Effect of castration on serum concentrations of gonadal hormones, insulin-like growth factor-I and its binding proteins in male pigs.
Ten male pigs (Large White x Landrace), 7 months old, were randomly allocated to two experimental groups. Five of them were castrated and the other five served as controls. Sera were collected on the day of castration and 1, 5, 6 and 7 weeks after castration for hormone assay. There was a significant rise in the splenic and pancreatic weights in the castrates (P < 0.01). The weights of prostate, seminal vesicles and bulbourethral glands were significantly decreased (P < 0.01) in the castrates, which is attributed to a fall in testosterone levels (P < 0.001). The fall in oestradiol concentrations (P < 0.001) in castrates confirms that the testis is the major source of oestrogens in males. Although there was no significant change in the body weight, serum IGF-I levels were elevated in the castrates as compared to the controls after 5, 6 and 7 weeks (P < 0.001). IGFBP bands of 43 and 39 kda predominate in both control and experimental groups indicating that castration had no effect on the IGFBP pattern. It is suggested that the increase in IGF-I levels may be due to uncoupling of GH/IGF-I axis induced by the decrease in steroid concentrations due to castration.
Umapathy
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Department of Physiology, School of Medicine, University of Zimbabwe.
Makinde
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MO
Mandisodza
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D000818:Animals; D002030:Bulbourethral Glands / Q000033:anatomy & histology; D004958:Estradiol / Q000097:blood*; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy; D009929:Organ Size; D011467:Prostate / Q000033:anatomy & histology; D012669:Seminal Vesicles / Q000033:anatomy & histology; D013552:Swine; D013739:Testosterone / Q000097:blood*; D015430:Weight Gain
D018969:Insulin-Like Growth Factor Binding Proteins; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I