This study is a complex investigation of alcohol-mediated changes in CYP2E1 mRNA and protein expression in the testes, as well as spermatogenesis indices and type I collagen amino acid contents, in male rats. Wistar albino male rats were divided into two groups: I--control (intact animals), II--experimental (chronic alcoholism, exposure to a 15% ethanol aqueous solution during 150 days). The destructive changes in the spermatogenic epithelium were accompanied by a decrease in sperm number and motility time. CYP2E1 mRNA and protein expression were elevated in the testes 3 and 1.4 times, respectively. Also, significantly lower contents of lysine, glutamic acid, serine, proline, alanine, valine, and phenylalanine residues accompanied by an increase of hydroxyproline, glycine, and threonine residue contents were detected in the skin type I collagen of the experimental group. Chronic ethanol consumption caused testicular failure along with an overexpression of CYP2E1 mRNA and protein in the testes as well as quantitative changes in type I collagen amino acid contents. The profound alcohol-mediated changes in collagen type I amino acid contents may have affected the spermatogenic epithelium state. The modulation of testicular cytochrome P450 2E1 mRNA and protein expression could change the functioning of this isozyme in target organs and take part in the mechanism of ethanol gonadotoxicity.