Supplemental administration of 1 alpha-hydroxyvitamin D3 inhibits promotion by intrarectal instillation of lithocholic acid in N-methyl-N-nitrosourea-induced colonic tumorigenesis in rats.
The effect of 1 alpha-hydroxyvitamin D3 [1 alpha(OH)D3] on promotion by intrarectal instillation of lithocholic acid (LC) in N-methyl-N-nitrosourea (MNU)-induced colonic tumorigenesis was studied in a rodent model. Ninety-two female F344 rats received intrarectal injection of 2.5 mg of MNU twice in one week followed by 1 mg of LC or its vehicle alone three times weekly for 48 weeks. Those which received LC were given a concomitant intragastric administration of 0.04 micrograms of 1 alpha(OH)D3 or its vehicle alone three times weekly. In the group receiving MNU alone (n = 30) five rats bore colonic tumors; in the MNU + LC group (n = 32) 15 and in the MNU + LC + 1 alpha(OH)D3 group (n = 30) six rats bore colonic tumors (MNU + LC versus MNU + LC + 1 alpha(OH)D3 group, P less than 0.05). These results indicated that promotion of MNU-induced colonic tumorigenesis by LC was suppressed by supplemental administration of 1 alpha(OH)D3.
Kawaura
A
A
Department of Internal Medicine, Hyogo College of Medicine, Japan.
Tanida
N
N
Sawada
K
K
Oda
M
M
Shimoyama
T
T
D000818:Animals; D003110:Colonic Neoplasms / Q000139:chemically induced*; D005260:Female; D006887:Hydroxycholecalciferols / Q000494:pharmacology*; D008095:Lithocholic Acid / Q000037:antagonists & inhibitors*; D008770:Methylnitrosourea; D051381:Rats; D011916:Rats, Inbred F344; D012007:Rectum
D006887:Hydroxycholecalciferols; D008095:Lithocholic Acid; D008770:Methylnitrosourea; C008088:alfacalcidol