Relationship between Growth Hormone (GH) Pulses in the Peripheral Circulation and GH-Releasing Hormone and Somatostatin Profiles in the Cerebrospinal Fluid of Goats

Journal of Veterinary Medical Science

Ding-Sheng CHEN¹  Jun-You LI²  Keitaro YAMANOUCHI¹  Toru SAWASAKI²  Masugi NISHIHARA¹  Kazutaka MOGI¹  Masatoshi SUZUKI¹  Tomohiro YONEZAWA¹ 

[1] Department of Veterinary Physiology, The University of Tokyo;Experimental Station for Bio-Animal Science, Veterinary Medical Science, The University of Tokyo

关键词: ghrelin;    growth hormone;    growth hormone-releasing hormone;    NPY;    somatostatin;   

DOI  :  10.1292/jvms.66.1071

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(49)Cited-By(13)Growth hormone (GH) is secreted in a pulsatile manner, but the underlying mechanisms of GH pulse generation remain to be resolved. In the present study, we investigated the relationship between GH pulses in the peripheral circulation and GH-releasing hormone (GHRH) and somatostatin (SRIF) profiles in the cerebrospinal fluid (CSF) of male goats. The effects of an intracerebroventricular (icv) injection of neuropeptide Y (NPY), galanin and ghrelin were also analyzed. Blood and CSF samples were collected every 15 min for 8 hr from the jugular vein and third ventricle, respectively. GH pulsatility in the goat was found to consist of distinct large pulses of 5 hr periodicity and small pulses of 1 hr periodicity. GHRH and SRIF in the CSF fluctuated in a pulsatile manner with 1 hr periodicity, and most of the descending phase of SRIF pulses were associated with the initiation of GH pulses. Icv injections of NPY, galanin and ghrelin stimulated GHRH release without affecting SRIF release. In addition, NPY suppressed, and galanin and ghrelin induced large GH pulses, although ghrelin was much more effective than galanin. These results suggest that an hourly fall in SRIF is involved in generating intrinsic circhoral rhythm of GH pulsatility. The mechanisms underlying the generation of large GH pulses of 5 hr periodicity remain unknown, while direct action of NPY and/or ghrelin on the pituitary might be involved.

【 授权许可】

Unknown