Impact of Maternal Chronodisruption on Female Offspring Puberty. A Role of Kisspeptin and Irisin

Abstract The neuroendocrine mechanisms regulating the onset of puberty are unclear. Kisspeptin is a potent gatekeeper of pubertal onset, but it has also been proposed that the time of puberty is dictated by kisspeptin independent mechanism. In this way, the myokine irisin could be involved in the puberty onset process serving as a metabolic trigger. Puberty is influenced by environmental factors like photoperiod. Maternal photoperiod influences postnatal development; thus alterations in maternal melatonin rhythm may affect the offspring’s reproductive axis development, especially at puberty. There is no research regarding the influence of maternal photoperiod on kisspeptin and irisin profile in offspring close to puberty. We investigated the influence of maternal photoperiod on serum kisspeptin and irisin levels during sexual development in female rat offspring.The study was carried out on female offspring Wistar rats at 25 and 30 days of age and in the vaginal opening day. Pregnant mother rats were included in three groups; control (12L/12 D), other exposed to continuous light during pregnancy (24L/0D), and the third exposed to continuous light as well as receiving daily melatonin during pregnancy. Serum kisspeptin and irisin were determined and vaginal opening day were registered. The results demonstrated that both continuous light exposure and melatonin treatment during intrauterine life affects kisspeptin and irisin secretion in the offspring during sexual maturation; these point out to an important role of the cytokine irisin in the onset of puberty.