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Effect of Corticotropin-Releasing Factor Receptor Antagonist on Psychologically Suppressed Masculine Sexual Behavior in Rats


Yoshiji Miwa, MD, PhD, Department of Urology, University of Fukui, 23-3 Shimoaizuki, Matsuoka, Fukui 910-1193, Japan. Tel: +81-776-61-8399; Fax: +81-776-61-8126; E-mail:


Introduction.  Corticotropin-releasing factor (CRF) coordinates various responses of the body to stress, and CRF receptors are important targets of treatment for stress-related disorders.

Aim.  To investigate the effect of a nonselective CRF receptor antagonist, astressin, on suppression of masculine sexual behavior by psychological stress in rats.

Methods.  First, we investigated the influence of psychological stress, induced 2 hours per day for three consecutive days, on sexual behavior. Then, rats were divided into 4 groups: a control group, an astressin administration group (A), a psychological stress loading group (PS), and a psychological stress loading and astressin administration group (PS + A). The rats were exposed to sham or psychological stress for three consecutive days. After the last stress loading, the rats were injected with vehicle or astressin, and their sexual behavior was observed. We also measured serum levels of adrenocorticotropic hormone (ACTH).

Main Outcome Measure.  The effects of astressin on sexual behavior and serum levels of ACTH in rats affected by psychological stress were determined.

Results.  Sexual behavior was reduced after psychological stress loading. The PS rats had significantly longer mount, intromission, and ejaculation latencies and lower ejaculation frequency than did the control, A, and PS + A rats. The intromission latency and ejaculation frequency in the PS + A rats did not achieve the level observed in the controls. There was no significant difference in these parameters between the control and A rats. Serum ACTH levels were significantly lower in PS + A rats than in PS rats.

Conclusions.  Psychologically suppressed masculine sexual behavior could be partially recovered with astressin administration in rats. These data provide a rationale for the further study of CRF receptor antagonists as novel agents for treating psychological sexual disorders. Miwa Y, Nagase K, Oyama N, Akino H, and Yokoyama O. Effect of corticotropin-releasing factor receptor antagonist on psychologically suppressed masculine sexual behavior in rats. J Sex Med 2011;8:688–695.