Thyrotropin-Releasing Hormone Stimulation and Somatostatin Inhibition of Growth Hormone Secretion from Perfused Rat Adenohypophyses*
- 1 June 1974
- journal article
- other
- Published by The Endocrine Society in Endocrinology
- Vol. 94 (6) , 1709-1713
- https://doi.org/10.1210/endo-94-6-1709
Abstract
Thyrotropin-releasing hormone (TRH) resulted in a 15–20-min pulse of growth hormone (GH) secretion from perfused rat hemipituitaries. Small but significant effects were seen with 0.1 ng/ml TRH, and growth hormone secretion was increased 104% with TRH in a concentration of 100 ng/ml. Pretreatment with T3in vivo or in vitro resulted in only slight suppression of the GH response to TRH. Theophylline (5.5 ITIM) and dibutyryl cyclic AMP (1 mM) both released GH, while 1 mM dibutyryl cyclic GMP had no effect on the secretion of GH. Basal GH secretion was inhibited by somatostatin, 100 ng/ml, and was followed by a rapid overshoot in GH release when somatostatin was discontinued; this “off signal” suggests the accumulation of a secretory stimulant during somatostatin administration. Somatostatin likewise inhibited GH secretion provoked by TRH or theophyllin. (Endocrinology94: 1709, 1974)This publication has 0 references indexed in Scilit: