The deleterious effect of mechanical dissociation of rat testes on the functional activity and purification of Leydig cells using Percoll gradients.

The effect of mechanically dispersing rat testes prior to collagenase treatment on the activity of the subsequently isolated Leydig cells has been investigated. The latter were obtained by centrifugation of the testes cells on Percoll density gradients. It was found that the lutropin-stimulated testosterone and cyclic AMP production were 5 and 3 times higher, respectively, in the purified Leydig cells when the mechanical dispersion was omitted, whereas the specific binding of human choriogonadotrophin was unchanged. It is concluded that mechanical treatment of rat testes, unlike mouse testes, decrease the activity of the Leydig cells.