RESUMEN
Rabbit antisera against mouse LDH-C_4 were generated by immunization of rabbits with highly purified mouse lactate dehydrogenase C_4. Immunofluorescent localization of LDH-C_4 on mouse and human sperms was performed by rabbit antibodies against mouse LDH-C_4 at 1:20 dilution of antisera. Sheep anti-rabbit IgGFITC conjugates at dilution of 1:10 was used as second antibody for the detection. Human sperms were obtained from fresh semen of fertile males. Mouse sperms were prepared from epididymis fluid of mature mice. Both human and mouse sperms were thoroughly washed by PBS buffer. Sections of 4 ?m mouse testes were made and dried on the slides for the immunohistochemical localization, ?-hydroxy-n-valeric acid was used as specific substrate in incubation medium for revealing the LDH-C_4 activity. Immunofluorescent studies demonstrated that LDH-C_4 can be found on the surface of mouse and human spermatozoa. In human spermatozoa, the strong fluorescence was seen on the neck and midpiece. On mouse sperm, the antibody binding was directed toward the tail segment with little or no binding on the head or midpiece. Histochemical studies showed that the intensive formazen deposits were on the neck and midpiece of human and mouse spermatozoa, as well as the cells approximate to the lumen of mouse seminiferous tubules.