TEMPORAL CHANGES IN SULFATED GLYCOPROTEIN-2 (CLUSTERIN) AND ORNITHINE DECARBOXYLASE MESSENGER-RNA LEVELS IN THE RAT TESTIS AFTER ETHANE-DIMETHANE SULFONATE-INDUCED DEGENERATION OF LEYDIG-CELLS

Short- (3-24 h) and long-term (4-50 days) changes in sulphated glycoprotein-2 (SGP3) and ornithine decarboxylase (ODC) mRNA levels in the adult rat testis were studied following a single dose of ethane-dimethane sulphonate (EDS), to destroy the Leydig cells. Distribution patterns of SGP-2 and ODC labelling were consistent with prevailing expression of the two transcripts in Sertoli cells and germ cells, respectively This pattern did not show appreciable changes following EDS administration. No labelling of SGP-2 mRNA was noted in the interstitium of control and EDS-treated rats. This finding indicates that Leydig cell death induced by EDS is not associated with increased SGP-2 mRNA levels, a phenomenon related to apoptotic cell death in many tissues. Semi-quantitative densitometric analysis of the preparations demonstrated differential changes in SGP-2 and ODC mRNA levels in:the tubular compartment following EDS treatment. At 6, but not at 3 and 12, h following EDS administration, SGP-2 mRNA levels showed a significant increase, possibly secondary to a direct effect of the alkylating agent on Sertoli cells. A significant decrease in ODC mRNA levels was observed from day 7 to day 28, matching degenerative changes in the seminiferous epithelium. In contrast, a decrease in SGP-2 transcript levels was observed from days 21-35 after treatment. In conclusion, our findings demonstrate that SGP3 mRNA, a putative marker of apoptosis, is not altered in the testicular interstitium during EDS-induced degeneration of Leydig cells. In the tubular compartment, the content of both ODC and SGP-2 mRNAs following EDS administration appears to be dependent mostly on the integrity of the germ cell complement and not to be influenced directly by changes in testosterone levels.