Methodological aspects of testicular blood flow measurements in rats.

3 techniques for the measurement of testicular blood flow in anesthetized adult rats were compared. Direct measurement of testicular venous outflow yielded values more than 3 times lower than those obtained Xe-133 clearance and radioactive microsphere techniques due to the surgical procedures involved in spermatic venous cannulation. There was an agreement between flow values obtained with Xe-133 clearance (17.8 +/- 3.5 ml/100 g X min) and radioactive microspheres (19.9 +/- 5.5 ml/100 g X min). A homogeneous distribution of microspheres to different segments of the testis indicates that Xe-133 clearance is an adequate technique for testicular blood flow measurements. However, for some experimental purposes the radioactive microsphere technique is more versatile than Xe-133 clearance because of its capacity of measuring several organ flows simultaneously.