ON THE INFLUENCE OF (STRIN INJECTIONS ON THE BALANCE BETWEEN THE PREHYPOPHYSEAL GONADOTROPIC HORMONES OF THE MALE RAT

¹ Institute of Physiology, University of Concepción, Chile

The injection of impure strin (from urine of the pregnant mare) into the adult normal male rat causes the luteinizing faculty of the prehypophysis, as revealed by subcutaneous administration to the infantile female rat, to be diminished whereas the strogenic faculty remains unaltered or is even sometimes increased.

The administration of male strin-prehypophysis does not always cause luteinization, although with the same quantities of male control prehypophysis a coefficient of luteinization of Q_lut = 0·95 may be obtained.

When greater quantities of strin-prehypophysis are given luteinization also occurs, but the coefficient of luteinization decreases as the number of the injections is increased (down to Q_lut = 0·12).

The effect of strin injections on the prehypophysis of the adult normal male rat is interpreted as being due to a change in the balance between the strogenic and the luteinizing gonadotropic hormones, the quantity of the luteinizing factor being diminished.

The prehypophyseal weight is greater in strin-injected adult male rats than in normal ones.

These results make it highly probable that the prehypophysis of the uncastrated adult male rat injected with strin behaves differently from the prehypophysis of the strin-injected castrated male.

strin injections produced in most cases a partial disturbance of spermatogenesis. Possibly autolytic substances emanating from the seminal tubules with disturbed spermatogenesis interfered in the gonadotropic balance of the prehypophysis.