Evaluation of methods for perfusing rat testes.

Organ perfusion methods offer a number of advantages in biologic studies but require full characterization before application. Two new methods for perfusing rat testes were characterized and compared with recirculating hemicorpus system. These preparations, selective and isolated testicular perfusion, are nonrecirculating and consequently, allow direct measurement of testosterone secretion. In both systems, testosterone production was a fuction of the dose of human chorionic gonadotropin in the perfusion medium up to 1000 mIU per ml which appeared to be inhibitory. The isolated testis method, in comparison with the selective, is more sensitive to human chorionic gonadotropin, requires less perfusion medium, maintains normal blood flow rates and water content, and is associated with no ischemia at commencement of perfusion. However, this system does not retain normal levels of ATP and GTP after 3 hr of perfusion. Whereas both procedures may be used for studies of testosterone secretion and androgen receptors, the inability to maintain testicular ATP and GTP levels indicates that present methods are not suitable for study of processes dependent upon high energy phosphate metabolism.