Assay of stanozolol for tumor initiating and promoting activity in two rat liver foci bioassays.
In this study stanozolol, one of the most abused anabolic steroids, was investigated for tumor initiating and promoting activity in two rat liver foci bioassays, using gamma-glutamyltranspeptidase (GGT) as marker for detection of putative preneoplastic foci. Stanozolol, orally administered for 2 weeks, at a dose level approximately 400-times larger than the human therapeutic dose, in rats initiated with N-nitroso-diethylamine according to the Solt-Farber system assay, did not produce any increase in the number and volume of GGT-positive liver foci. A 6-week oral treatment with stanozolol (430 ppm in the diet) followed by 2 weeks of 2-acetylaminofluorene (AAF) diet (200 ppm), carried out according to the Tatematsu assay system to evaluate the initiating activity, did not provoke any significant modification of the number and volume of GGT-positive foci as compared to the controls. In the rats receiving AAF (200 ppm in the diet for 2 weeks) followed by 6 weeks of stanozolol, to evaluate the promoting activity, an increase in number and volume of the GGT-positive foci was observed at the highest oral dose, but the differences from the corresponding control values which resulted were not statistically significant. Taken as a whole the results of this study do not provide any substantial evidence of carcinogenic activity of stanozolol in rat liver, even when orally administered at high doses.
Ghia
M
M
Institute of Pharmacology, University of Genoa, Italy.
Mereto
E
E
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D008099:Liver / Q000187:drug effects*; D008113:Liver Neoplasms / Q000139:chemically induced; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced; D009929:Organ Size / Q000187:drug effects; D011230:Precancerous Conditions; D051381:Rats; D013197:Stanozolol / Q000633:toxicity*; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D013197:Stanozolol; D005723:gamma-Glutamyltransferase