Melatonin Implants Have No Effect on the Testis Volume and Body Weight in Mongolian Gerbils

Authors : Alper KARAKAŞ, Bülent GÜNDÜZ

Pages : 209-214

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Publication Date : 2003-12-01

Article Type : Research Paper

Abstract :Photoperiod is an important environmental cue in the regulation of reproductive activity in Mongolian gerbils. Photoperiodic information is ultimately transduced into a hormonal signal by the pineal gland. We examined the effect of constant-release melatonin capsules on the testicular size and body weights of male Mongolian gerbils exposed to a long insert ignore into journalissuearticles values(14L: 10D); photoperiod. Three groups were formed: control insert ignore into journalissuearticles values(n = 10);, intact + melatonin implant insert ignore into journalissuearticles values(n = 10); and pinealectomy + melatonin implant insert ignore into journalissuearticles values(n = 10);. The testes and body weights of the gerbils were recorded every week for 8 weeks. Body weights insert ignore into journalissuearticles values(76 ± 2.0 g intact + melatonin implant; 79 ± 3.0 g pinealectomy + melatonin implant); and testes weights insert ignore into journalissuearticles values(1.54 ± 0.21 g intact + melatonin implant; 1.47 ± 0.19 g pinealectomy + melatonin implant); of intact + melatonin implanted and pinealectomy + melatonin implanted groups were not statistically different from those of the control group insert ignore into journalissuearticles values(80 ± 3.1 g body weight; 1.55 ± 0.20 g testes weight); insert ignore into journalissuearticles values(P > 0.05); at the end of the study. Regardless of treatment, the animals fully reflected the characteristics of a long photoperiod. These results indicate that masking the endogenous melatonin rhythm via constant-release melatonin implants has no effect on the testis volume or body weight of Mongolian gerbils when the animals are kept in a long photoperiod.
Keywords : Implantation, Melatonin, Pinealectomy, Gerbil