Contractile responses of rat lateral gastrocnemius and soleus to dianabol (17 beta-hydroxy-17-methyl-1,4-androstadien-3-one) and exercise.

Rats were maintained for 8 weeks on a program of twice weekly subcutaneous injections of 0.075 mg Dianabol (methandrostenolone) and treadmill running to investigate the ability of this compound to increase skeletal muscle contractility. The lateral gastrocnemius isometric twitch and tetanic tensions of the Dianabol Exercise group were both 1.5 times that of the Control animals. Treatment with either Dianabol or exercise alone did not affect the contractile strength of this muscle. The contractility of the soleus was not altered by any of the treatments employed. Withholding of steroid injections midway through the 8 week treatment period while maintaining exercise administration did not alter the effect observed in the Dianabol Exercise group. It is concluded from the results of this study that concomitant administration of Dianabol and exercise for 8 weeks can have a marked effect on isometric force characteristics of skeletal muscle in young adult male rats.