Ans. c. GliomaOctreotide is a synthetic analogue of somatostatin and its pharmacological actions are similar to somatostatin, used in insulinoma, glucagonoma and carcinoid tumors but not in glioma."Somatostatin is a hypothalamic peptide that regulates the function of several endocrine and exocrine glands.Somatostatin acts primarily as a negative regulator of a variety of different types of cells blocking processes such as cell secretion, cell growth and smooth muscle contraction. It is secreted from the hypothalamus into the portal circulation and travels to the anterior pituitary gland where it inhibits the production and release of both growth hormone and thyroid stimulating hormone: Somatostatin is present in many tissues other than hypothalamus. It is also secreted by the cells in the pancreas and in the intestine where it inhibits the secretin of variety of hormones. " Action of Somatostatin BrainGITPancreasInhibits the release of:* Growth hormone* Thyroid stimulating hormoneInhibits the release of:* Gastrin* Chofecystokinin* Secretin* Motilin* Vasoactive intestinal polypeptide* Gastric inhibitory polypeptideInhibits the release of:* Insulin* Glucagon"By virtue of its pharmacological actions. Octreotide has been used to treat the symptoms associated with metastatic carcinoid tumors (flushing and diarrhea) and vasoactive intestinal peptide (VIP) secreting adenomas."Octreotide* Most widely used somatostatin analogue* Preferentially binds to SSTR-2 and SSTR-5 receptors* Administered subcutaneously; Peak effects within 30 minutes* Half life: 90 minutes; Duration of action: 12 hours* Adverse reactions: Nausea, abdominal pain and gall stones0Indications* Decreases GH secretion (indicated in acromegaly)* Decreases TSH secretion (indicated in thyrotrope adenomas)* Decreases insulin (indicated in insulinoma)* Decreases glucagon (indicated in glucagonoma)* Secretory diarrhea* Variceal bleeding* Pancreatitis* Intestinal dysmotilityBy virtue of its pharmacological actions, Octreotide has been used to treat the symptoms associated with metastatic carcinoid tumors (flushing and diarrhea) and vasoactive intestinal peptide (VIP) secreting adenomas.