Naloxone has a Local Effect on the Testis of Immature Rats

Abstract
The local effect of naloxone on testicular weight, compensatory hypertrophy and differentiation of the testis and serum testosterone level was studied in immature rats. A single injection of naloxone in a dose of 2 .mu.g/testis under the testicular capsule significantly increased the testicular weight, promoted testicular differentiation and enhanced the rate of compensatory hypertrophy of the remaining testis in unilaterally orchidectomized animals. Apparently, naloxone has a direct effect on the testis of immature rats.