Apoptosis and p53 gene expression in male reproductive tissues of cadmium exposed rats

Reverse transcription (RT) PCR technique was used to investigate the mechan ism of apoptosis induced by Cd and the change of its related genes in teste s and prostate of rats, Adult male rats were given a single (s.c.) injectio n of CdCl2 0, 2.5, 5.0, 10 mu mol/kg. 48 h and 72 h after administration of Cd, animals were sacrificed. The results indicated that Cd can induce apop tosis in testes via p53-independent pathway. No apoptosis occurred in prost ate in any of the Cd-exposed groups. There was a clearly negative relations hip in testes between p53 gene expression and Cd exposure and this dose-res ponse relationship was observed both at 48 h and 72 h, There was a very sma ll increase of this gene expression in the dorsolateral lobe of the prostat e in Cd exposed groups. The other apoptosis related gene, bcl-x, was not de tectable in either control or Cd-exposed group in testes and dorsal prostat e, Although the MT-I gene was expressed in testes or dorsal prostate both i n control and exposed groups, no overexpression of MT-I gene was found afte r administration of Cd, The expression of MT-I in the ventral prostate was not detected in the control group, but a weak expression was found after Cd exposure. Since p53 is a tumor suppressor gene which can inhibit tumorigen esis, the consequence of a Cd-induced decrease of p53 in testes may have a relation to the known risk of Cd tumorigenesis in this tissue.