Biochemical changes in denervated cremaster muscle and its relationship to spermatogenesis in the bonnet monkey

Abstract

Transection of genitofemoral nerve resulted in a number of changes in the composition of the bonnet monkey cremaster muscle in a 58 day period. Total fat, glycogen/g wet wt and total DNA/g wet wt increased, whereas the water content and the levels of total protein and RNA decreased. On presentation/unit DNA, protein increased suggesting volume changes of the muscle fiber on denervation. There was about 34.56 ± 1.26% atrophy in muscle fiber as measured by its cross-sectional area. Sarcoplasmic protein/unit wet wt remained unaltered, while collagenous proteins increased and myoglobin, myosin and actin content decreased. Levels of ATP, creatine phosphate and pyruvate also decreased while ADP, creatine, Pi and lactate concentrations increased. A significant reduction in lactic dehydrogenase, creatine phosphokinase, phosphorylase, actomyosin and myosin ATPase and Na-azide sensitive ATPase activities were noted after denervation. “Phosphate potential” indicating the efficiency of phosphorylating systems decreased suggesting that the denervated muscle has a greater utilization and a lower phosphorylating efficiency. Together with these changes, a number of histological changes in testis were recorded. The seminiferous tubules atrophied and the lumen was obliterated. The majority of germ cells became edematous and the Sertoli cells degenerated. The changes observed in testes closely resemble those brought about by exposing the testes to higher temperature. It is suggested that the loss of “trophic” influence due to denervation impairs muscle function and the regulatory mechanisms concerned with temperature in the scrotum.