Consequences of Accelerated Gain and Growth Hormone Administration for Lipid Metabolism in Growing Beef Steers

Peters, J. P.

doi:10.1093/jn/116.12.2490

Cited by 92 publications

(63 citation statements)

References 34 publications

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“…45,135 ± 137 This ®nding is in line with the reduction of body fat observed in ad libitum fed, but not in calorie-restricted, beef steers after bovine GH administration. 138 GH treatment is known to increase resting energy expenditure (REE), whose main determinant is LBM, in both GH de®cient adults 139 ± 141 and in obese patients on a weight-maintaining diet. 137 In our experience, 133 rhGH administration was effective in preventing the diet-induced reduction of REE and enhancing the energy metabolism of LBM even in severely calorie-restricted obese women.…”

Section: Effects Of Gh Administration On Body Composition In Obesitymentioning

confidence: 99%

Growth hormone in obesity

1999

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Growth hormone (GH) secretion, either spontaneous or evoked by provocative stimuli, is markedly blunted in obesity. In fact obese patients display, compared to normal weight subjects, a reduced half-life, frequency of secretory episodes and daily production rate of the hormone. Furthermore, in these patients GH secretion is impaired in response to all traditional pharmacological stimuli acting at the hypothalamus (insulin-induced hypoglycaemia, arginine, galanin, L-dopa, clonidine, acute glucocorticoid administration) and to direct somatotrope stimulation by exogenous growth hormone releasing hormone (GHRH). Compounds thought to inhibit hypothalamic somatostatin (SRIH) release (pyridostigmine, arginine, galanin, atenolol) consistently improve, though do not normalize, the somatotropin response to GHRH in obesity. The synthetic growth hormone releasing peptides (GHRPs) GHRP-6 and hexarelin elicit in obese patients GH responses greater than those evoked by GHRH, but still lower than those observed in lean subjects. The combined administration of GHRH and GHRP-6 represents the most powerful GH releasing stimulus known in obesity, but once again it is less effective in these patients than in lean subjects. As for the peripheral limb of the GH ± insulin-like growth factor I (IGF-I) axis, high free IGF-I, low IGF-binding proteins 1 (IGFBP-1) and 2 (IGFBP-2), normal or high IGFBP-3 and increased GH binding protein (GHBP) circulating levels have been described in obesity. Recent evidence suggests that leptin, the product of adipocyte speci®c ob gene, exerts a stimulating effect on GH release in rodents; should the same hold true in man, the coexistence of high leptin and low GH serum levels in human obesity would ®t in well with the concept of a leptin resistance in this condition. Concerning the in¯uence of metabolic and nutritional factors, an impaired somatotropin response to hypoglycaemia and a failure of glucose load to inhibit spontaneous and stimulated GH release are well documented in obese patients; furthermore, drugs able to block lipolysis and thus to lower serum free fatty acids (NEFA) signi®cantly improve somatotropin secretion in obesity. Caloric restriction and weight loss are followed by the restoration of a normal spontaneous and stimulated GH release. On the whole, hypothalamic, pituitary and peripheral factors appear to be involved in the GH hyposecretion of obesity. A SRIH hypertone, a GHRH de®ciency or a functional failure of the somatotrope have been proposed as contributing factors. A lack of the putative endogenous ligand for GHRP receptors is another challenging hypothesis. On the peripheral side, the elevated plasma levels of NEFA and free IGF-I may play a major role. Whatever the cause, the defect of GH secretion in obesity appears to be of secondary, probably adaptive, nature since it is completely reversed by the normalization of body weight. In spite of this, treatment with biosynthetic GH has been shown to improve the body composition and the metabolic ef®cacy of lean body mass in obese pa...

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Section: Effects Of Gh Administration On Body Composition In Obesitymentioning

confidence: 99%

Growth hormone in obesity

1999

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“…(1989) investigated the interaction betwcen diet and rcsponse to growth hormone in lambs and were able to show that the reduction in fat G It0 W'I'H content is related to the extent to which the control animals are depositing fat, the biggest reductions being seen in animals on a high plane of nutrition. Although some incrcases in muscle mass are seen in animals on a low plane of nutrition (Peters, 1986) maximal effects will only be seen in animals receiving an adequate protein intake (Enright, 1989). The work of Breier et al (1988a,b) and of Elsasser et af.…”

Section: G R O W T H H O R M O N Ementioning

confidence: 99%

Growth promotion in farm animals

Buttery

Dawson

1990

Proc. Nutr. Soc.

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“…De même, la diminution des niveaux de l'insulinémie, le relèvement de ceux de la GH et le maintien de la glycémie sont en accord avec les observations faites chez les Bovins sous-alimentés (Peters, 1986 ;Bocquier et al, 1992) ou à jeun .…”

Section: Introductionunclassified

“…Certains travaux menés chez les Bovins en croissance (Peters, 1986) ou en lactation (Cisse et al, 1991) et chez le mouton (Parkes et Bassett, 1985) (Brockman, 1990 (Niijima, 1989), un mécanisme mettant en jeu le réflexe vagal a également été proposé chez le mouton (Bassett, 1974b) (Trenkle, 1978 …”

Section: Introductionunclassified