title: Alteration of free sulphydryl content of rat sperm heads by suppression of intratesticular testosterone.
abstract: Subcutaneous injections of testosterone propionate to adult male rats at a dose of 2.5 or 10 mg/kg body weight, 3 times per week for 7 weeks, resulted in a 75% reduction in serum LH and more than 50% reduction in intratesticular testosterone concentration, but serum FSH levels remained unchanged. The free -SH content, measured as iodo[14C]acetamide binding, increased by 70-100% in testicular sperm heads after suppression of testicular testosterone, and by 25-30% in caput epididymal sperm heads but was decreased by 70-80% in cauda epididymal sperm heads. These results demonstrate an alteration in the oxidative state of sperm nuclear basic proteins, suggesting incomplete nuclear maturation. These changes may be specific for the suppression of intratesticular testosterone, thus illustrating the androgen dependency of sperm head maturation. The contrast effects noted between the iodo[14C]iodoacetamide binding by the caput and the cauda epididymal sperm heads indicate that testosterone propionate treatment may affect the mechanisms regulating the oxidation of the sulphydryl residues in sperm heads during epididymal transit. This alteration may not directly relate to the tissue androgen concentrations.
mesh_terms: D000818:Animals; D003864:Depression, Chemical; D007460:Iodoacetamide / Q000378:metabolism; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008858:Microscopy, Phase-Contrast; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013077:Sperm Head / Q000187:drug effects / Q000378:metabolism*; D013079:Sperm Maturation; D013094:Spermatozoa / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D013438:Sulfhydryl Compounds; D013739:Testosterone; D007986:Luteinizing Hormone; D007460:Iodoacetamide