The effect of temperature on the potential difference and input resistance of rat seminiferous tubules

摘要

1. The p.d. of rat seminiferous tubules was 5·86 ± 0·15 mV, lumen negative, at 33° C and varied linearly with temperature between 24 and 37° C, exhibiting an apparent Q10^{25-35° C} of 2·0 with a slope of 0·43 mV/° C. Exposing testes to a temperature of 37-43° C resulted in an initial hyperpolarization followed by depolarization of the tubules. These changes were more rapid in testes exposed to 41-43° C than in testes exposed to 37-39° C.2. The Rin of seminiferous tubules was 198 ± 7·8 kΩ at a testis temperature of 33° C. The Rin decreased when testes were maintained at 37 and 41° C, the rate of decrease being similar to the rate of depolarization.3. Exposing testes to deep body temperature by unilateral surgical cryptorchidism caused a reduction of 30 and 64% in tubular p.d. and Rin respectively when measured 24 hr after surgery. Exposure to deep body temperature for up to 4 days did not cause any further change in either parameter.4. There was no evidence that lanthanum penetrated through the Sertoli cell tight junctions after exposing testes to 41° C for up to 30 min.5. The results indicate that the seminiferous tubule p.d. is maintained by a temperature-sensitive, cellular mechanism. Exposing testes to deep body temperature or above depolarized the tubules and increased their permeability.