GH secretion in two siblings with Laron's dwarfism: the effects of glucose, arginine, somatostatin, and bromocryptine

The Journal of Clinical Endocrinology and Metabolism
J J AlcañizB Barcelo

Abstract

The secretion of GH in two siblings with clinical dwarfism and high GH plasma levels (the mean of several basal values; 233.83 ng/ml in patient A and 178.16 in patient B has been studied with several dynamic tests. An arginine infusion increased GH levels in both cases (+193.55% for A, +140.27% for B). No significant modifications were obtained with oral glucose tolerance test +18.70% for A, +24.32% for B). A bolus of somatostatin almost completely prevented the rise in GH levels in response to arginine. Pretreatment with bromocryptine clearly increased basal GH plasma levels (A, +58.66%; B, +56.03%) and the response to arginine. As in the case of a normal hypothalamus, the hypothalamus of Laron's syndrome responds to arginine and bromocryptine, with GH elevations. Somatostatin suppresses GH levels. A lack of response to glucose can be considered as a nonspecific effect of the very low biological activity of the stimulus in a hyperstimulated hypothalamus. We suggest that GH secretion by the hypothalmo pituitary system in Laron's syndrome is normal, and that GH hyperproduction may be due to a generalized defect in GH receptors or to the low levels of somatomedin.

References

Jul 1, 1996·Baillière's Clinical Endocrinology and Metabolism·K A Woods, M O Savage
Nov 15, 1990·The New England Journal of Medicine·A L RosenbloomP J Fielder
Nov 1, 1983·Clinics in Endocrinology and Metabolism·A Gómez-Pan, M D Rodriguez-Arnao
Sep 24, 2020·Reviews in Endocrine & Metabolic Disorders·Zvi Laron, Haim Werner
Jan 11, 1991·Acta Paediatrica Scandinavica. Supplement·J Guevara-AguirreR G Rosenfeld

Related Concepts

Arginine hydrochloride
Oral Glucose Tolerance Test
Novothyral
Recombinant Insulin-Like Growth Factor
Somatomedin Assay
Pituitary Diseases
Somatomedins
Thyroid Hormone Plasma Membrane Transport Defect
Glucose, (beta-D)-Isomer
Process of Secretion

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