Studies on the Mechanism of Growth Hormone and Thyrotropin Responses to Somatostatin Antiserum in Anesthetized Rats

Kazuo Chihara, Akira Arimura, Mieko Chihara, Andrew V. Schally

Research output: Contribution to journalArticlepeer-review

58 Scopus citations

Abstract

An iv administration of 1 ml sheep antiserum to somatostatin (anti-SS) resulted in marked increases of both serum GH and TSH, with a peak 10-20 min after administration in male rats anesthetized with urethane or pentobarbital. Administration of anti-SS had no effect on serum PRL. Ablation of the basal medial hypothalamus abolished the rises of both serum GH and TSH after anti-SS administration. Intravenous injection of 1 ml rabbit antiserum to TRH (anti-TRH) decreased serum TSH levels 15 min after injection, whereas injection of normal rabbit serum did not affect TSH levels. Serum TSH levels did not rise after injection of anti-SS in rats pretreated with anti-TRH. On the other hand, pretreatment with anti-TRH did not affect the basal serum GH levels nor the anti-SS-induced GH release. The enhanced secretion of GH and TSH after anti-SS injections was not blocked by pretreatment with indomethacin, an inhibitor of prostaglandin synthesis. The following conclusions were made: both GH and TSH responses to anti-SS require an intact basal medial hypothalamus; TSH response to anti-SS is mediated by hypothalamic TRH; and the GH response may be mediated by hypothalamic GH-releasing hormone which is not TRH or prostaglandins.

Original languageEnglish (US)
Pages (from-to)1916-1923
Number of pages8
JournalEndocrinology
Volume103
Issue number5
DOIs
StatePublished - Nov 1978
Externally publishedYes

ASJC Scopus subject areas

  • Endocrinology

Fingerprint Dive into the research topics of 'Studies on the Mechanism of Growth Hormone and Thyrotropin Responses to Somatostatin Antiserum in Anesthetized Rats'. Together they form a unique fingerprint.

Cite this