title: Further studies on the effect of leupeptin, a protease inhibitor, on induction of bladder tumors in rats by N-butyl-N-(4-hydroxybutyl)nitrosamine.
abstract: The effect of a microbial protease inhibitor, leupeptin, on the induction of urinary bladder tumors in W rats by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was examined. Three groups of animals were given 0.01% BBN in their drinking water for 12 weeks. A basal powder diet supplemented with 0.1% leupeptin was given to group A throughout the experiment and to group B when BBN administration was stopped. Group C was given the basal  diet without leupeptin throughout the study. The total preservation period was 40 weeks. Results clearly showed that when leupeptin was given during the promotion step of bladder carcinogenesis (as in group B), it increased the size of tumors and the incidences of cancer and invasion. When leupeptin was given throughout the experiments, its effect was counteracted (as in group A).
mesh_terms: D000818:Animals; D002085:Butylhydroxybutylnitrosamine / Q000008:administration & dosage; D004347:Drug Interactions; D007976:Leupeptins / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced; D009602:Nitrosamines / Q000008:administration & dosage; D009842:Oligopeptides / Q000494:pharmacology*; D011480:Protease Inhibitors; D051381:Rats; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced* / Q000648:ultrastructure
chemical_list: D007976:Leupeptins; D009602:Nitrosamines; D009842:Oligopeptides; D011480:Protease Inhibitors; D002085:Butylhydroxybutylnitrosamine