CA2135813A1 - Treatment of obesity - Google Patents

Abstract

A method for the treatment of obesity in an animal such as a human, comprises administering to the animal an effective amount of a peptide which comprises the carboxyl-terminal sequence of a growth hormone, particularly the carboxyl-terminal sequence of human growth hormone containing amine acid residues 177-191. A pharmaceutical composition for use in the treatment of obesity is also disclosed.

Description

TREATMENT OF OBESITY

FIELD OF THE INVENTION

This invention relates to the treatment of obesity in animals. In particular, the invention relates to the treatment of obesity in humans, although it is to be understood that the present invention also extends to the treatment of obesity in non-human mammals, for example, for the improvement of meat qualities in farm 10 animals used in food production.

BACKGROUND OF THE INVENTION.

The critical role of human growth hormone (hGH) in postnatal growth in 15 humans is well recognised. Less obvious is the impact of this hormone on the regulation of lipid and carbohydrate metabolism, due to lack of detailed molecular studies.

lt is well docu",ented that the predominant form of hGH is a globular 20 protein with a molecular weight of 22,000 daltons (22-KD) and consists of 191amino acid residues in a single-chain, folded by 2 disulphide bonds with a smallloop at the carboxyl terminus between residues 182 and 189. Recent crystallographic studies also show that the hGH ,nelecule contains four anti-parallel a-helices which are arranged in a left-twisted, tightly-packed helical 25 bundle'. The cGncept that there are discrete functional domains within the hGH
molecule responsible for speciric metabolic actions of the hormone is generall accepted. The amino-terminus has been ider,liried as the functional domain responsible for the insulin-like actions of the hGH molecule23.

Recombinant DNA technology opens the way to the large-scale commercial production of human growth hormone, and the recG"Ibinant hGH appears to have equivalent biological efficacies and pharmacokinetic properties 4'5. Current supply 941 103,p:\op\jm~,0~ .spc,1 of this multiple-functional hormone no longer restricts the types and numbers ofexperimental therapies in humans and animals. The use of hGH for treatment of short stature in children and adults is well-established6. Therapeutic effects of hGH in female infertility have also been reported 7~8, Treatment of human obesity 5 with hGH has been advocated because of its remarkable effects on body composition with lipid metabolism9. However, the clinical applications of the intact hormone encounter a variety of problems. Evidence suggests that this multiple-functional hormone often simultaneously exerts in vivo, by various bioactive domains within the molecules, some adverse effects'.
Regulation of lipid metabolism by GH was first described in 1959 by Raben & Hollenberg1'. The acute increase of plasma free fatty acids after GH
administration was the major evidence for this metabolic function of the hormone.
The regulatory role of the hormone in lipid metabolism was subsequently 15 supported by the body composition studies of GH-deficient and GH-treated humans'2'3 and pjg514~15 The findings of Gertner suggest that hGH is linked to adipose tissue distribution through a series of interactions known as the 'GH-fat cycle"6. However, the mlolecul~ events transpiring to these biochemical and physiological changes remained largely unknown. The Illetab~lic effects of GH
20 on adipose and other tissues in vivo are variable and complex, apparently consisting of at least two cG""~onents, an early insulin-like effect followed by a later more profound anti-insulin effect". The results of the latter effect may include both a stimulation of lipolysis and an inhibition of lipogenesis. The anti-lipogenic effect of hGH has been sul)s~ ,liated with the dei"on~l,dliGns of the 25 decrease of the e3~.ressiol- of glucose transporter GLUT 4 in adipocytes'8, the inhibition of the activity of acetyl-CoA carboxylase in ~ipose tissues'920 and the reduction of glucose incorporation into lipid in both isolqted cells and tissues2' 22.

In view of the multiple-functional effects of intact hGH and the problems 30 encountered in clinical applications of the intact hGr",one, work leading tothe present invention has been directed to investig-~ting whether hGH derivatives could be synthesised that retain the dasi,ed bioactivities and lack the unwanted 941 103,~,.\.,,~.\, 0~ ~ .sp~,2 .

side effects. In this work, structure-function studies of hGH have been carried out to elucidate the molecular mechanism of the metabolic actions of this multiple-functional hormone.

The structure-function studies of hGH with synthetic hormonal fragments have revealed that the carboxyl terminus of the hGH molecule appears to be the functional domain of the hormone for the regulation of lipid metabolism20232425 and it has now been shown that a synthetic peptide having a sequence based in the carboxyl terminal region reduces body weight gain and adipose tissue mass 10 in a laboratory obese animal model.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided a 15 method for the treatment of obesity in an animal, which comprises administering to the animal an effective amount of a peptide which comprises the carboxyl-terminal sequence of a growth hormone.

As used throughout this specificdtion, the term "obesity" is used to include 20 both excess body weight and excess adipose tissue mass in the animal, and correspondingly the references to l,eabnent of obesity include both reduction ofbody weight gain and reduction of adi~,ose tissue mass of the obese animal.

P,eferably, the animal is a human although the invention also extends to 25 the treatment of non-human mammals. Preferably also, the peptide comprises the carboxyl-terminal sequence of human growth hormone containing amino acid residues 177-191 (hereindrler referred to as hGH 177-191). Alternatively, the peptide may comprise the carboxyl-terminal sequence of the growth hor"lone of other non-human mammalian spee es, such as bovine, porc;ne, ovine or equine 30 growth hormone, corresponding to the hGH 177-191 peptid~.

941 103,~,.\, \, C`l ~ .5pc,3 ~.

It will, of course, be appreciated that the present invention extends to the use of peptides having longer amino acid sequences than the particular sequence 177-191 of growth hormone, for example the sequence 172-191 of human growth hormone or the corresponding sequence of growth hormone of other non-human 5 mammalian species, however the present invention does not extend to the use of intact full-length human growth hormone or growth hormone of other animal species. The present invention also extends to the use of peptides which are homologues, analogues, mutants, variants or derivatives of the native carboxyl-terminal sequences of human growth hormone or growth hormone of other animal 10 species, and which are derived from natural or synthetic (including recombinant) sources, provided always that the resulting peptide retains the biological activity of the native carboxyl-terminal sequence described herein, namely the ability toreduce body weight gain and adipose tissue mass in an obese animal.

These homologues, analogues, mutants, variants or derivatives may be derived by insertion, deletion or substitution of amino acids in, or chemical modification of, the native carboxyl-terminal sequence. Amino acid insertional derivatives include amino and/or carboxylic terminal fusions as well as intra-sequence insertions of single or multiple amino acids. Insertional amino acid 20 sequence variants are those in which one or more amino acid residues are introduced into a predetermined site in the protein although random insertion isalso possible with suitable screening of the resulting product. Deletional variants are chara~;tarised by the removal of one or more amino acids from the sequence.
Substitutional amino acid variants are those in which at least one amino acid 25 residue in the sequence has been replaced by another of the twenty primary protein amino acids, or by a non-protein amino acid. Chemical modificatiGns of the native carboxyl-terminal sequence include the acetylation of the amino-terminus and/or amidation of the carboxyl-terminus and/or side chain cyclisationof the native carboxyl-terminal sequence.
The term "effective amount" as used herein means an amount of the peptide surricient to attain the desired effect in the lledlll~elll of obesity in the 941 103~p.\ r \~ . ~ 5~4 ..

animal, but not so large an amount as to cause serious side effects or adverse reactions.

In another aspect, the present invention provides the use of an effective 5 amount of a peptide which comprises the carboxyl-terminal sequence of a growthhormone as described above in the treatment of obesity in an animal or in the manufacture of a pharmaceutical composition for the treatment of obesity in an animal.

In yet another aspect, the present invention provides a pharmaceutical composition for use in the treatment of obesity in an animal, comprising an effective amount of a peptide which comprises the carboxyl-terminal sequence of a growth hormone as described above, together with one or more pharmaceutically acceptable carriers and/or diluents.
The peptide which is the active ingredient of the pharmaceutical composition of this aspect of the invention exhibits advantageous therapeutic activity in the treatment of obesity in an animal when administered in an amountappropriate to the particular case. For exampla, from about 0.5 ~9 to about 20 20 mg per kilogram of body weight per day may be administered. Dosage regimens may be adjusted to provide the optimum prophylactic or therapeutic response. Forexample, one or more divided doses may be administered daily, weekly, monthly or in other suitable time intervals or the dose may be proportionally reduced asindicated by the exigencies of the clinical situation.
The active ingredient may be adn,inistared in any convenient manner such as by the oral, parenteral (including intrape,itoneal, intravenous, subcutaneous, intramuscular and inl,~i"edullary injeçtion), ir,(,anasal, intradermal or suppository routes or by implanting (eg using slow release m~'e~ules). For ease of 30 administration, oral admini~l,alion is pref~r,ed, however parenteral adminial,ation is also quite convenient. Depending on the route of administration, the active ingredient may be required to be coated in a material that protects said ingredient 941 103,~ pe,5 from the action of enzymes, acids and other natural conditions which may inactivate the said ingredient. For example, low lipophilicity of the ingredient may allow it to be destroyed in the gastrointestinal tract by enzymes capable of cleaving peptide bonds and in the stomach by acid hydrolysis. In order to 5 administer the composition by other than parel1teral administration, the active ingredient may be coated by, or administered with, a material to prevent its inactivation.

The active ingredient may also be administered in dispersions prepared in 10 glycerol, liquid polyethylene glycols, and/or mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations will usually contain a preservative to prevent the growth of microorganisms.

The pharmaceutical forms suitable for injectable use include sterile 15 aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the conta" ,inating action of 20 microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, forexample, by the use of a coali"g such as lecithin, by the maintenance of the 25 required particle size in the case of dispersion and by the use of surfactants. The prevention of the action of microor~anis",s can be brought about by various antibacterial and antifungal agents, for exam~le, parabens, chlorobutanol, phenol, sorbic acid, thiomorosal, and the like. In many cases, it will be p~f~rdbl~ to include isotonic agents, for example, sugars or sodium chlGride. Prolonged 30 absorption of the injectable compositions can be brought about by, for example, the use in the cGillposilions of agents delaying abs~r,uliGn.

94 1 103,~ , .spe,6 213581~

Sterile injectable solutions are prepared by incorporating the active ingredient in the required amount in the appropriate solvent with various of theother ingredients enumerated above, as required, followed by filtered sterilisation.
Generally, dispersions are prepared by incorporating the sterilised active 5 ingredient into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injec~ble solutions, the preferred methods of preparation are vacuum drying and the freeze-drying technique which yield a powder of the active ingredient plus any additional desired ingredient from 10 previously sterile-filtered solution thereof.

When the active ingredient is suitably prote..ted as described above, the composition may be orally administered, for example, with an inert diluent or with an assimilable edible carrier, or it may be enclosed in hard or soft shell gelatin 15 capsule, or it may be compressed into tablets, or it may be incG,,uorated directly with the food of the diet. For oral admi"isl,dliGn, the active ingredient may beincorporated with excipients and used in the form of ingestable tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contai~1 at least 0.01% by weight and more 20 preferably at least 0.1-1% by weight of active ingredient. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 5 to about 80% of the weight of the unit. The amount of active ingredient in the pharmaceutical cGi"positions is such that a suitable dosage will be obtained. rlefer,ed cG",positions or preparaliGi,s according to the present 25 invention may, for example, be prepared so that an oral dosaga unit form contains between about 0.5 ~9 and 200 mg and more pre~3rably 10,ug and 20 mg of active ingredient.

The tablets, troches, pills, c~psl!'es and the like may also contain the 30 following: a binder such as gum l,agacantl" ~cia, corn starch or gelatin;
excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium 941 lo3~p:\opa~ ob~sir/ sFe~7 .

stearate; and a sweetening agent such a sucrose, lactose or saccharin may be added or a flavouring agent such as peppermint, oil of wintergreen, or cherry flavouring. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier. Various other materials may be 5 present as coatings or to otherwise modify the physical form of the dosage unit.
For instance, tablets, pills, or capsules may be coated with shellac, sugar or both.
A syrup or elixir may contain the active compound, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavouring such as cherry or orange flavour. Of course, any material used in preparing any dosage 10 unit form should be pharmaceutically pure and substantially non-toxic in the amounts employed. In addition, the active ingredient may be incorporated into sustained-release preparations and formulations.

As used herein, pharmaceutically acceptable carriers and diluents include 15 any and all solvents, dispersion media, aqueous solutions, coatings, antibacteria!
and antifungal agents, isotonic and absorption delaying agents, and the like. The use of such media and agents for pharmaceutically active substances is well known in the art, and it is described, by way of example, in Remington's Pharmaceutical Sciences, 1 8th Edition, Mack Publishing Company, Pennsylvania, 20 USA. Except insofar as any conventional media or agent is incompatible with the active ingredient, use thereof in the pharmaceutical compositions of the presentinvention is conlemplated. Supplementary active ingredients can also be incorporated into the compositions.

It is especially advantageous to formulate compositions in dosage unit form for ease of admini lldlion and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary ~os~ges for the human suhjects to be treated; each unit containing a predetermined quantity of active ingredient calculated to produce the desired tl,erapeutic effect in associdlion with 30 the required pharmaceutical carrier and/or diluent. The specifications for the novel dosage unit forms of the invention are di~tated by and directly dependent on (a) the unique characteristics of the active ingredient and the particular 941 103,p.~, \; obe~i~y.sp~,8 2l~58l3 therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active ingredient for the treatment of obesity.

Throughout this specification and claims which follow, unless the context 5 requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Further details of the present invention will be apparent from the following 10 Example and the accompanying drawings which are included by way of illustration, not by way of limitation, of this invention.

In the drawings:

Figure 1 shows the effect of hGH 177-191 peptide on cumulative weight gains in male (panel A) and female (panel B) C57BU6J (ob/ob) mice during an 18-day treatment period. Animals were given a daily intraperitoneal injection of 0.1 ml of either saline (-,-) or synthetic hGH 177-91 peptide (200 ~g/kg body weight) (O,v). Body weight changes were determined at 3-day 20 intervals and each point represent~ the mean + SEM of 6 animals. The differences between the saline control and the hGH 177-191 treated groups were statistically analysed. ~P~0.05 and ~p~0.025 compared with corresponding controls.

Figure 2 shows the average daily food consul"ption (g/mouse/day) of C57BU6J (ob/ob) mice during an 18-day treat",ent period with hGH 177-191 peptide. The treatment for the four groups of animals was as described in Figure1. Food consumption of each group was determined at 3-day intervals and each point represents the mean + SEM of 6 animals. No significance between the 30 groups was observed at all times.

941 103~ .spe.9 Figure 3 shows the ex vivo effect on lipogenesis in adipose tissues of the C57BU6J (ob/ob) mice after 18-day treatment with hGH 177-191. The tissues were preincubated at 37C for 1 hr in Krebs-Ringer Bicarbonate buffer (pH 7.4) containing 1% defatted BSA and 1 mM glucose. After preincubation, 5 tissues were transferred to fresh media containing ['4C]-glucose (0.05 ~Ci/~mol) for a further 90 min incubation. Data indicate the rate of '4C-lipid synthesis and are expressed as '4C-glucose incorporated into lipid (pmol/mg tissue/min). Values are mean + SEM of 12 determinations from 6 animals of each group. The differences between the hGH 177-191 treated and saline control groups were 10 statistically significant (~p<0.1, *~p<0.05).

EXAMPLE

MATERIALS AND METHODS
Animals and t.~al".ents.

Twelve male and twelve female C57BU6J (ob/ob) mice aged 12-13 weeks were used in this study. The animals of the same sex were randomly divided into 20 two groups, housed 6 per cage and maintained on a normal 1 2-hr lighVdark cycle at a constant room temperature of 25C in the animal house of the Biochemistry Department, Monash University, Clayton, Australia. Animals were fed ad libitum on pre-determined quantity of mouse pellets (Clark King, Melbourne, Australia) and allowed free ~ccess to water at all times. The mice were given a daily 25 intraperitoneal (i.p.) injection of 0.1 ml of either the hGH 177-191 peptide (200 ,ug/kg body weight) or equivalent volume of physiological saline (0.9% sodium chloride) for 18 days. The i.p. injection was administered with a 30G x 1/2" (0.31 x 13 mm) needle on a 1-ml disposable tuberculin syringe, and the site of injection was the lower left quadrant of the abdomen of the animals.

941103,p.\, \; Ot ~.spe.10 Peptide synthesis. l l hGH 177-191, Leu-Arg-lle-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe, was prepared by manual solid-phase synthesis of Fmoc-strategy using DlC/HOBt activation. The coupling reactions were monitored by using the 5 ninhydrin method2~. Acetamidomethyl(Acm) group was used for the side-chain protective group of two Cys residues. After completion, the peptide was cleaved from the resin and side-chain protective groups, except Acm, were removed by using Reagent K27. Removal of two Acm groups and simultaneous formation of the disulfide bond between Cys182 and Cys189 of hGH 177-191 were performed 10 using the silyl-sulfoxide method28. Aller"dlively, other methods for formation of direct disulfide bonds may be used. After puriricalion on RP-HPLC, the oxidised hGH 177-191 peptide was characterised with Waters Pico Tag (PITC) system for amino acid analysis [Arg: 1.92 (2), Cys: not determined (2), Glu/Gln: 2.00 (2), Gly: 2.27 (2), lle: 0.84 (1), Leu: 1.19 (1), Phe: 1.10 (1), Ser: 1.54 (2), Val: 1.84 15 (2)] and with fast atom bombardment-mass spect,ometer (FAB-Mass) for molecular weight determination, [M+H]' I 1652.0 (experimental) for 1651.9 (calculated).

Cumulative weight gain and food consumption.
Cumulative weight gain and food consumption were determined at 3-day intervals by the measurements of body weight and uneaten food remaining in the cages. The animals were placed in a covered cha",ber to minimise movement during the weighing procedure. The food consumption data were obtained by subtracting the amount of uneaten food remaining in the cages from the original 25 provision.

Assays for plasma triglyceride and total cholesterol.
The animals were anaesll,etised with sodium pentobarbitone (80 mgA~g body weight) 12 hr after the last dose of hGH 177-191. Blood samples were 30 collected from the tail vein of anaesll ,etised animals 45 mins after the administration of anaesthetic. After being centrifuged at 2000 x 9 for 5 minutes, plasma was removed from the samples and used for metabolite assays.

941103,p.~, \; OL ~.spe,ll Triglyceride and total cholesterol in plasma were measured by enzyme-spectrophotometric methods. The reagents are based on either a modified glycerol phosphate oxidase (GPO)-Trinder s type colour reaction29 or a cholesterol oxidase-4-aminoantipyrine method30. All assays were performed with the 5 CentrifiChem System 400 (Union Carbide) containing an automated pipetter a centrifugal analyser and a recording spectrophotometer. Seronorm Lipid (Nycomed Pharma Co. Oslo Norway) was used as the calibrator.

Deterrnination of adipose ti~sue weight.
The procedure for the isolation and measuren,ent of intact epididymal fat pads was established in previous studies of epididymal growth of GH-deficient (liVlit) mice. In the present study white adipose tissues either whole epididymal or parametrical fat pads were excised with the identical techniques as previously described22 from the mice immediately after sacrifice. The tissues were washed 15 in cold physiological saline blotted and weighed. For ex vivo lipogenic assays the portions of adipose tissues without blood vessels were used.

Assay for lipogenic activity.
The rate of the incor~oraliGn of exogenous ['4C]-glucose into total lipid in 20 adipose tissue was measured as the index of lipogenic activity253'32. Adiposetissues were sliced into segments of approximately 200 mg each and then placed in Krebs-Ringer Bica,bonate (KRB) buffer (pH 7.4) co"lai"ing 1% deralled BSA
and 1 mM glucose and gassed with 95% 2 - 5% CO2 at 37C. After 1 hr preincubation the tissues were transfer,ed to another 2 ml of fresh media 25 containing ['4C]-gll~cose (final specific activity 0.05 ~Ci/f~mol) for a further 90 min incubation (conditions as above). Then the tissues were removed washed thoroughly with KRB buffer and lipid was exl,dcted with a chlorofor"~/methanol mixture33. '4C radioactivity was counted in a Wallac 1410 Liquid Scintillation Counter. The rates of total lipid synthesis are expressed as pmol ['4C]-glucose 30 incorporated into lipid/mg tissue/min.

stati~ l analyQis.

-~1 103,p.~, \ Ot ~ pe,12 . .

The Student's t-test was used to analyse the results. All data are expressed as the mean + SEM. P values of ~0.05 are accepted as statistically significant.

RESULTS

The chronic treatment of the obese mice with the synthetic hGH 177-191 peptide was evaluated by the measurements of a number of parameters including cumulative body weight gain and daily food consumption. Figure 1 reveals that 10 the control female animals appeared to have a larger mean cumulative body weight gain than their control male counterparts, similar to the observation previously reported by Ingalls et a/.34. During the 18-day treatment period, a clear reduction of cumulative body weight gain was observed in the hGH 177-191-treated male as well as female animals when compared with the appropriate 15 controls, indicating that the hGH fragment reduces the body weight gain in the obese mouse model. When the data were analysed and expressed as daily body weight gains, the treated male animals reduced their body weight gain from 0.22 + 0.03 to 0.16 + 0.04 g/day and the female animals from 0.30 ~ 0.02 to 0.22 +
g/day. The average daily body weight gains of the both male and female treated 20 animals showed approximately 27% lower than those of the appropriate control groups. However, no significant difference in the average daily food consumptionamong the 4 groups was observed over the study period (Figure 2). It was noted that the ratio of daily food consu",ptiGn to daily body weight gain between the l,adted animals and control ones was dirferer,l. 25 + 4 to 36 + 8 for the male 25 mice and 18 i 2 to 27 ~ 6 for the female mice. These data clearly demonstratethat the chronic treatment with the hGH 177-191 peptide reduced the body weight gains without arfactins~ food cons~""plion.

As indicated by the measure"~el)ts of epididymal and parametrical fat pads, 30 the l,aated mice sigr,iricantly reduced their adipose tissue weights up to 20% in the males and 12% in the femdlas as compared with the controls of the same sex (Table 1). Lipogenesis is subject to the supply of precursor metabolites such as 941 103~p.\1 r \~ Ol ~j .5pe~ 13 213S81~

glucose and acetate. The effect of hGH 177-191 on lipogenesis was therefore determined by measuring the incorporation of ['4C]-glucose into lipid in isolated adipose tissues. The hGH 177-191 peptide inhibited the lipogenesis from 2.80 + 0.33 to 2.33 + 0.21 pmol/mg tissue/min in the males and from 3.36 + 0.13 to 5 2.99 + 0.21 pmol/mg tissue/min in the females (Figure 3). These results are consistent with the reductions in adipose tissue mass and cumulative body weightgain previously observed. Table 2 depicts the effect of the hGH 177-191 treatment on the profiles of circulating levels of triglyceride and cholesterol. The total cholesterol in plasma was significantly reduced from 4.44 + 0.56 to 3.52 +10 0.39 mmol/l in the male animals but the plasma levels of cholesterol in the treated female animals were only slightly lower than those of control ones. The responses to hGH 177-191 l,edl"~e"l between the male and female mice appeared to be different in this respect. On the other hand hGH 177-191 did not influence the plasma levels of triglyceride in both sexes.
TABLE 1 Effect of sy,ltl,etic hGH 177-191 peplide on body weight and adipose tissue mass of obese mice after 18-day chronic treatment.
Animals were given a daily i.p. inj~ion of either hGH 177-191 (200 g/kg body weight) or equivalent volume of saline as control. All data represent the mean + SEM of 6 animals (~p<0.1; ~p~0.05).

Male Female Item Control Treated Control Treated Initial body wt.(g) 47.5 + 3.1 48.6 + 2.0 46.7 ~ 3.6 48.2 ~ 3.4 Final body wt.(g) 51.4 ~ 3.0 51.5 ~ 2.3 52.1 ~ 3.2 52.2 + 2.9 Body wt.gain(g)~" 3.9 + 0.6 2.9 ~ 0.6~ 5.4 ~ 0.4 4.0 + 0.6 Adipose tissue (g)(b) 3.18~ 0.43 2.52~ 0.25~ 3.67+ 0.54 3.26~ 0.25~
(a) The dirrerence between the initial and final body weights were considered as body weight gain.
(b) The intact epididymal or para",~:~,ical fat pads were the representative adipose tissues.

941 103,~ , \; 0~ ~, .spe,14 TABLE 2 Effect of synthetic hGH 177-191 on plasma levels of triglyceride and total cholesterol in obese mice after 18-day chronic treatment.
Blood samples were collected from the cut tips of the tails of the anaesthetised animals. Data represent the mean + SEM of 6 animals (~p<0.05).

Male Female Item Control Treated Control Treated Triglyceride 0.63 ~ 0.26 0.58 ~ 0.16 0.41 ~ 0.19 0.38 ~ 0.11 (mmol/l) Cholest~rol 4.44 ~ 0.56 3.52 ~ 0.39~ 3.01 ~ 0.52 2.84 ~ 0.29 (mmol/l) 941103.~,.\., \, .Ol ~,.5pc,15 REFERENCES:
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941103~ \Sr \; Ot ~,.sp~.17

Claims (10)

1. A peptide which comprises the carboxyl-terminal sequence of a growth hormone for the treatment of obesity in an animal.

2. Use of a peptide which comprises the carboxyl-terminal sequence of a growth hormone in the treatment of obesity in an animal.

3. Use of a peptide which comprises the carboxyl-terminal sequence of a growth hormone in the manufacture of a pharmaceutical composition for the treatment of obesity in an animal.

4. A pharmaceutical composition for use in the treatment of obesity in an animal, comprising an effective amount of a peptide which comprises the carboxyl-terminal sequence of a growth hormone together with one or more pharmaceutically acceptable carriers and/or diluents.

5. A composition according to claim 4, wherein the peptide comprises the carboxyl-terminal sequence of human growth hormone.

6. A composition according to claim 5, wherein the peptide comprises the carboxyl-terminal sequence of human growth hormone containing amino acid residues 177-191.

7. A composition according to claim 4, wherein the peptide comprises a homologue, analogue, mutant, variant or derivative obtained by insertion, deletion or substitution of amino acids in, or chemical modification of, the native carboxyl-terminal sequence of human growth hormone.

8. A composition according to claim 4, wherein the peptide comprises the carboxyl-terminal sequence of the growth hormone of a non-human mammalian species.

9. A composition according to claim 8, wherein the peptide comprises the carboxyl-terminal sequence of the growth hormone of a non-human mammalian species which corresponds to the sequence of amino acid residues 177-191 of human growth hormone.

10. A composition according to claim 4, wherein the peptide comprises a homologue, analogue, mutant, variant or derivative obtained by insertion, deletion or substitution of amino acids in, or chemical modification of, the native carboxyl-terminal sequence of the growth hormone of a non-human mammalian species.