Phosphofructokinase in the Rat Testis: Changes in Isozyme Patterns during Maturation and Short Term Cryptorchidism1

Abstract

Phosphofructokinase [EC 2.7.1.11] (PFK) isozymes were separated, using polyacrylamide disc gel electrophoresis, in extracts of rat kidney, liver, testis, seminiferous tubules and testicular interstitium. Isozyme patterns were observed in the developing rat testis between 20 days and 120 days of age and in the artificially cryptochid testis at 2, 12, 24 and 96 h and 16 days after surgery. Kidney extracts contained 5 separable isozyme bands, designated A, B, C, D and E in order of increasing mobility. Liver contained 2 isozymes, with mobilities identical to A and B and adult testes contained A, C, D and E. Isozymes A and C were found in separated seminiferous tubules and D and E were restricted to interstitial elements of the testis. All 4 testicular isozymes were present at 20, 30, 40, 50, 60 and 120 days of age; A, C and D decreased in staining intensity during development and E increased. No changes in isozyme patterns were observed during 2-96 h of artificial cryptorchidism, but 2 additional bands were found at 16 days. One of these was slightly more mobile than band A, similar to band B; one was slightly less mobile. No evidence was found for a heat labile PFK isozyme that is specific to spermatogenic cells.