Ranitidine and cimetidine differ in their in vitro and in vivo effects on human colonic cancer growth.
Histamine has recently been shown to be a growth factor for some gastric and colorectal cancer cells. Previous studies have shown that cimetidine blocks in vitro and in vivo histamine-stimulated growth and cAMP release from the human colonic cancer cell line, C170. In this study, ranitidine, another H2 receptor antagonist, did not affect either basal or histamine-stimulated in vitro proliferation of C170, and failed to prevent cAMP release in vitro. Ranitidine did not inhibit in vivo growth of C170 at a dose of 1, 10, 25, 50 or 100 mg/kg, in contrast to 50 mg/kg/day cimetidine, which produced 39.3% inhibition of tumour volume (p<0.01) after 23 days' treatment. Ranitidine did not inhibit in vivo histamine-stimulated growth of C170 cells . LIM2412, another colonic cancer cell line, was significantly stimulated by both cimetidine and ranitidine in vivo. Ranitidine had no effect on in vitro cell proliferation.
Lawson
J A
JA
UNSW Department of Surgery, The St. George Hospital, Kogarah Sydney, Australia.
Adams
W J
WJ
Morris
D L
DL
D000230:Adenocarcinoma / Q000473:pathology*; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002927:Cimetidine / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000473:pathology*; D000242:Cyclic AMP / Q000096:biosynthesis; D004347:Drug Interactions; D006632:Histamine / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011899:Ranitidine / Q000494:pharmacology*; D013268:Stimulation, Chemical; D014407:Tumor Cells, Cultured / Q000187:drug effects
D006635:Histamine H2 Antagonists; D002927:Cimetidine; D006632:Histamine; D011899:Ranitidine; D000242:Cyclic AMP