Melatonin implants have no effect of the testis volume and body weight in mongolian gerbils

Mongolian gerbillerin üreme aktivitelerinin düzenlenmesinde fotoperiyot önemli bir faktördür. Fotoperiyodik bilgi en son pineal bez tarafından hormonal sinyale çevrilir. Bu çalışmada uzun fotoperiyotta (14L: 10D) tutulan Mongolian gerbillerin testis boyutlarına ve vücut ağırlıklarına, sürekli salınım gösteren melatonin hormonunun etkisini inceledik. Üç grup oluşturuldu; kontrol (n = 10), intakt + melatonin implantasyonu (n = 10) ve pinealektomi + melatonin implantasyonu (n = 10). Sekiz hafta süresince gerbillerin testis ve vücut ağırlık değişimleri haftada bir kaydedildi. Deney sonunda intakt + melatonin implantasyonu ve pinealektomi + melatonin implantasyonu gruplarının vücut ağırlığı (76 ± 2,0 g intakt + melatonin implantasyonu; 79 ± 3,0 g pinealektomi + melatonin implantasyonu) ve testis ağırlıkları (1,54 ± 0,21 g intakt + melatonin implantasyonu; 1,47 ± 0,19 g pinealektomi + melatonin implantasyonu) ile kontrol grubu (80 ± 3,1 g vücut ağırlığı; 1,55 ± 0,20 g testis ağırlığı; P > 0,05) arasında anlamlı bir farklılık tespit edilmedi. Uygulamalara bakmaksızın, hayvanlar uzun fotoperiyodun özelliklerini gösterdiler. Bu sonuçlar göstermektedir ki sürekli salınan melatonin implantasyonları ile maskelenen endojen melatonin ritmi, hayvanlar uzun fotoperiyotta tutuldukları zaman testis hacmi ve vücut ağırlığı üzerinde bir etki göstermemektedir.

Mongolian gerbillerde melatonin implantasyonlarının testis hacmi ve vücut ağırlıkları üzerine bir etkisi yoktur

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 constantrelease melatonin capsules on the testicular size and body weights of male Mongolian gerbils exposed to a long (14L: 10D) photoperiod. Three groups were formed: control (n = 10), intact + melatonin implant (n = 10) and pinealectomy + melatonin implant (n = 10). The testes and body weights of the gerbils were recorded every week for 8 weeks. Body weights (76 ± 2.0 g intact + melatonin implant; 79 ± 3.0 g pinealectomy + melatonin implant) and testes weights (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 (80 ± 3.1 g body weight; 1.55 ± 0.20 g testes weight) (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.

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