The hypothalamic peptide that exerts a direct inhibitory effect on pituitary GH secretion, while also suppressing TSH, glucagon, and pancreatic exocrine secretion, is:
- A Growth hormone-releasing hormone (GHRH)
- B Ghrelin
- C Somatostatin (GHIH) ✓
- D Neuropeptide Y
Correct answer: C. Somatostatin (GHIH)
Explanation
Somatostatin (growth hormone-inhibiting hormone, GHIH) is produced by the periventricular nucleus of the hypothalamus and also by pancreatic delta cells. It inhibits pituitary GH and TSH secretion, suppresses glucagon and insulin release from the pancreas, and reduces gastric acid and pancreatic enzyme secretion. Its broad inhibitory role makes it distinct from other hypothalamic peptides. Ghrelin, produced mainly in the stomach, stimulates GH.
Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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