Publication: Cerrahi olarak menopoz oluşturulmuş sıçanlarda melatonin tedavisininöstrojen, progesteron ve vitamin D’nin serum düzeylerine etkisi7
Abstract
Amaç: Bifosfonatlar menopoz sonrası osteoporozda kemik kütlesinin korunması amacıyla sıklıklakullanılmaktadır. Melatonin kemik metabolizmasında da düzenleyici rolü olduğu düşünülen birantioksidan hormondur. Ancak seks hormonları ve Vitamin D düzeylerine etkisi daha önceçalışılmamıştır.Gereç ve Yöntem: Anestezi altında, Sprague-Dawley sıçanlara (n=40) bilateral overektomi (OVT) ve taklitcerrahi (n=8) uygulanmıştır. Cerrahiden dört hafta sonra OVT’li sıçanlar serum fizyolojik (1 ml/kg/gün),melatonin (25 mg/kg/gün), alendronat (70 µg/kg/hafta) veya melatonin + alendronat ile sekiz hafta tedaviedilmişlerdir. Sıçanlar dördüncü (n=8) ve 12. haftanın (n=12) sonunda kalpten kan alınarak sakrifiyeedilmiştir.Bulgular: Overektomiden sonraki dördüncü ve 12. haftalarda serum östrojen seviyelerindeki düşüş(p<0,05) melatoninle kontrol düzeyine dönmüştür (p<0,001). Ancak melatonin+alendronatla tedaviedilen gruplarda bir değişiklik görülmemiştir. Öte yandan, 12. haftanın sonunda OVT grubundaprogesteron düzeylerinde bir değişiklik görülmezken, melatonin, alendronat veya kombine tedaviyapılan gruplarda anlamlı bir artış saptanmıştır (p<0,05-0,001). Seks hormon bağlayıcı globülindüzeylerinde OVT gruplarının hiçbirinde farklılık oluşmamış, fakat melatonin grubunda anlamlı olmayan biryükseliş eğilimi gözlenmiştir. Benzer olarak, yalnızca melatonin tedavili grupta Vitamin D düzeylerindeanlamlı bir artış bulunmuştur. (p<0,01-0,001).Sonuç: Bulgularımız melatoninin over-dışı seks hormonlarının ve Vitamin D’nin sentezinde bir rolüolduğunu düşündürmektedir. Melatoninin hormon replasman tedavisinde yeni bir terapötik ajan olarakkullanılabilmesi için klinik araştırmalara gereksinim vardır.
Aim: In order to maintain bone mass in post-menopausal osteoporosis, bisphosphonates (e.g. alendronate) are frequently used, while the antioxidant agent melatonin was also suggested to have a regulatory role in bone physiology. However, their impact on the serum levels of sex hormones and vitamin D was not studied before. Materials and Methods: Under anesthesia, Sprague-Dawley rats (n=40) underwent bilateral ovariectomy (OVT), while control group had sham surgery (n=8). Four weeks after the surgery, OVT rats were treated with saline (1 ml/kg/day), melatonin (25 mg/kg/day), alendronate (70 µg/kg/week) or melatonin + alendronate for 8 weeks. Rats were euthanized at the end of 4th (n=8) or 12th weeks (n=40). Results: At the 4th and 12th weeks after OVT, serum levels of estrogen were depressed (p<0.05), while melatonin abolished the reduction in estrogen (p<0.01), but OVT-induced reduction in estrogen levels was still evident in alendronate or melatonin + alendronate-treated groups. Despite that progesterone levels were not significantly changed by OVT on the 12th week, melatonin, alendronate or their combination elevated progesterone levels (p<0.05-0.001). Sex hormone binding globulin was not altered significantly in none of the OVT groups, while a tendency to increase was observed by melatonin treatment. Similarly, in only melatonin-treated group, serum levels of Vitamin D were elevated significantly (p<0.01-0.001). Conclusion: The results implicate that melatonin may have an impact on the extraovarian synthesis of sex hormones and vitamin D, suggesting its clinical investigation as a potential therapeutic agent for hormone replacement therapy.
Aim: In order to maintain bone mass in post-menopausal osteoporosis, bisphosphonates (e.g. alendronate) are frequently used, while the antioxidant agent melatonin was also suggested to have a regulatory role in bone physiology. However, their impact on the serum levels of sex hormones and vitamin D was not studied before. Materials and Methods: Under anesthesia, Sprague-Dawley rats (n=40) underwent bilateral ovariectomy (OVT), while control group had sham surgery (n=8). Four weeks after the surgery, OVT rats were treated with saline (1 ml/kg/day), melatonin (25 mg/kg/day), alendronate (70 µg/kg/week) or melatonin + alendronate for 8 weeks. Rats were euthanized at the end of 4th (n=8) or 12th weeks (n=40). Results: At the 4th and 12th weeks after OVT, serum levels of estrogen were depressed (p<0.05), while melatonin abolished the reduction in estrogen (p<0.01), but OVT-induced reduction in estrogen levels was still evident in alendronate or melatonin + alendronate-treated groups. Despite that progesterone levels were not significantly changed by OVT on the 12th week, melatonin, alendronate or their combination elevated progesterone levels (p<0.05-0.001). Sex hormone binding globulin was not altered significantly in none of the OVT groups, while a tendency to increase was observed by melatonin treatment. Similarly, in only melatonin-treated group, serum levels of Vitamin D were elevated significantly (p<0.01-0.001). Conclusion: The results implicate that melatonin may have an impact on the extraovarian synthesis of sex hormones and vitamin D, suggesting its clinical investigation as a potential therapeutic agent for hormone replacement therapy.