The Effects of Cryptorchism in the Guinea Pig on the Isoenzymes of Testicular Lactate Dehydrogenase

Abstract

Unilateral cryptorchism was produced in guinea pigs by returning one testis to the abdominal cavity and by preventing its re-entry into the inguinal canal and scrotal sac. The retained testes were examined after 1-2, 3-4, or 5-7 weeks and estimates made of Iactate dehydrogenase activity. Disk electrophoresis in 7.5% acrylamide gel was used to separate the isoenzymes of Iactate dehydrogenase in the scrotal and cryptorchid testes. Scrotal testis contained 2 isoenzymes not found in heart of muscle. Cryptorchism produced a rapid decrease in the amounts of these isoenzymes. The activities of Iactate dehydrogenase sub units were calculated. Heart-type sub unit activity did not change significantly during cryptorchism but muscle-type subunit activity rose shrply within 3-4 weeks, falling slightly at 5-7 weeks. Testis-type subunit activity fell rapidly and at 5-7 weeks had disappeared. A rise in Iactate dehydrogenase activity occurred in the scortal testis during the experimental period.