Interaction between Leptin and Growth Hormone (GH)/IGF-I Axis

Endocrine Journal

OSAMU ISOZAKI¹  HITOSHI SEKI²  MEGUMI MIYAKAWA¹  TOSHIO TSUSHIMA¹  HIROSHI DEMURA¹ 

[1] Department of Medicine, Institute of Clinical Endocrinology, Tokyo Women's Medical College;Sumitomo Pharmaceuticals Research Center

关键词: GH;    Obese;    ob gene;    Leptin;    Adipose tissue;   

DOI  :  10.1507/endocrj.46.Suppl_S17

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(20)Cited-By(7)In order to identify the mutual interaction between GH and leptin, we studied the effect of GH on fatty Zucker rats. GH administration at a high dose (5.0IU/kg) reduced % body fat after 7 days. The leptin mRNA level in subcutaneous fat tissue was not changed but that in epididymal fat tissue was decreased by an even lower dose of GH (1.5IU/kg). IGF-I treatment (200μg/kg/day) did not change the % body fat or leptin mRNA level. These observations suggest that GH directly interacts with visceral fat and reduces fat mass and leptin expression. We also measured serum leptin levels in patients. The levels in patients with acromegaly were significantly lower than those in normal subjects with the same amount of body fat, but serum IGF-I and urinary C peptide excretion rates were higher in the acromegalic. These observations also suggests that GH directly interacts with adipose tissue and reduces leptin expression. Next we investigated the direct action of leptin on GH release from the pituitary. Leptin pretreatment of pituitary cells in culture or rats in a fasted or fed condition did not change GRH induced GH secretion. As indicated also by other recent studies, leptin may increase GRH or decrease somatostatin secretion by the hypothalamus. Thus GH interacts with fat tissues and leptin may be a good marker of the interaction.

【 授权许可】

Unknown