Resumen de Effect of human menopausal gonadotropin on testicular morphometry, gonadal and extragonadal sperm reserves of rabbit bucks
Anietie Archibong Ansa, James A. Imasuen
Testicular morphometry, gonadal and extragonadal sperm reserves of rabbit bucks treated with Human Menopausal Gonadotrophin (Menogon®) were studied. Twenty-four crossbred rabbit bucks weighing 1.3-1.6 kg at 15-17 wk were randomised into 4 treatment doses of 0 (control), 7.5, 15.0, and 22.5 I.U. in a completely randomised design with 6 bucks per group. A vial of Menogon® was reconstituted in 1 mL of physiological saline solution and administered intramuscularly at 72 h intervals for 56 d prior to commencement of sample collection. Parameters evaluated were ejaculate concentration, testicular morphometry, gonadal and extragonadal sperm concentrations. Results for ejaculate concentration (86, 110, 186, and 135×106/mm3) revealed a significantly (P<0.05) higher difference in the 15.0 I.U. group. Gonadal and extragonadal sperm reserve indices were not significantly (P>0.05) affected by the treatment. Testicular morphometry results showed that paired testis volume (cm3), testis circumference (cm), ductus deferens length (cm) and epididymal length (cm) were significantly (P<0.05) different, with a progressive increase that corresponds to increased Menogon® administration. High and positive correlations (P<0.01) were observed between testis weight and gonadal sperm reserves (r=0.99) and body weight and gonadal sperm reserves (r=0.99). Similarly, correlations between epididymal weight and epididymal sperm reserves (r=0.85), testis weight and ejaculate concentration (r=0.97), body weight and ejaculate concentration (r=0.96), body weight and testis weight (r=0.97), testis volume and ejaculate concentration (r=0.97), testis volume and gonadal sperm reserve (r=0.91), testis volume and testis weight (r=0.96), and testis volume and body weight (r=0.90) were positive and significant (P<0.05). Taking all the reported results into consideration, controlling the amount of Menogon® administration at 15.0 I.U. for rabbit bucks could be a promising approach to regulating testosterone synthesis and secretion, thereby affording a potential method of enhancing fertility.
