The effect of somatostatin on 5-hydroxytryptamine release from a carcinoid tumor.

Abstract

One of the major manifestations of the carcinoid syndrome is secretory diarrhea thought to be due to overproduction of 5-hydroxytryptamine (5-HT). Synthetic somatostatin analogues have proved to be clinically effective in controlling this diarrhea. We have established a continuous cell line from a human pancreatic carcinoid tumor that secretes 5-HT. We examined the ability of the somatostatin analogue, SMS 201-995, to inhibit 5-HT release in vitro. Tumor cells were exposed to SMS 201-995 (10(-6) mol/L), pentagastrin (10(-9) mol/L), acetylcholine (10(-5) mol/L), and isoproterenol (10(-5) mol/L) alone and in combination; 5-HT release was assayed with high pressure liquid chromatography. We found that pentagastrin (6.43 +/- 0.64 ng/ml), isoproterenol (20.24 +/- 2.17 ng/ml), and acetylcholine (12.39 +/- 1.10 ng/ml) each stimulated release of 5-HT compared to control values (4.38 +/- 0.42 ng/ml). SMS 201-995 significantly reduced release of 5-HT in response to isoproterenol and acetylcholine but did not inhibit the effect of pentagastin. These data suggest that different agents do not act through the same pathway to stimulate 5-HT release from human pancreatic carcinoid cells.

• Authors: J P Lawrence, J Ishizuka, B Haber, C M Townsend Jr, J C Thompson
• Journal: Surgery (Surgery) Vol. 108 Issue 6 Pg. 1131-4; discussion 1134-5 (Dec 1990) ISSN: 0039-6060 [Print] United States
• PMID: 1978946 (Publication Type: Journal Article)

Chemical References

• Serotonin
• Somatostatin
• Pentagastrin
• Isoproterenol
• Acetylcholine
• Octreotide

Topics

• Acetylcholine (pharmacology)
• Carcinoid Tumor (metabolism)
• Humans
• Isoproterenol (pharmacology)
• Octreotide (pharmacology)
• Pancreatic Neoplasms (metabolism)
• Pentagastrin (pharmacology)
• Serotonin (metabolism)
• Somatostatin (pharmacology)
• Tumor Cells, Cultured