Thyrotropin-releasing hormone somatotropin

Somatotropin release inhibiting hormone (SIH), somatostatin a polypeptide, M, 1638, which inhibits secretion of somatotropin, thyrotropin, insulin, glucagon, gastrin and cholecystokinin. SIH has a broad activity spectrum it acts outside the hypothalamus as a neurotransmitter in the central nervous system, and as a hormone in the intestinal tract it has also been found in the thyroid and pancreas. 

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