Effect of melatonin and change in expression of clock genes in ovary of polycystic ovarian syndrome rat model

Abstract

Modern lifestyle significantly shapes the health of mammals, offering newlineconveniences but also posing threats. Night shift work and contemporary habits newlinecan newlineadversely affect reproductive health, disrupting the endogenous newlinephotoperiodic balance. newlineThe length of day and night or photoperiod, affects mammals including humans newlinediversifyingly. It exerts a notable influence on various physiological aspects such newlineas circadian rhythm, reproduction, melatonin secretion, vitamin D synthesis, newlinemood and behavior in mammals by regulating sleep-wake cycle. Synchronization newlineof this environmental cue with endogenous system or circadian rhythm is newlinemaintained by biological clock. This internal time regulator is found in supra newlinechiasmatic nucleus (SCN) or master clock and various peripheral tissues such as newlineovary, skeletal muscle, liver. newlineWhen light information passes SCN through the retino-hypothalamic pathway it newlinehelps reset the internal clock in response to external light-dark cycles. In SCN, newlinethe expression of clock genes such as period (Per) and cryptochrome (Cry) is newlineregulated. These genes are part of a feedback loop that generates circadian newlinerhythm. The gene responsible for positive feedback loop is Bmal1 and Clock. newlineWhen photic signal reaches the SCN, it adjusts the phase of this feedback loop, newlineensuring that the internal clock aligns with the external light-dark cycle. The SCN newlinein turn synchronize its signal to pineal gland and peripheral tissues to harmonize newlinevarious physiological processes including reproduction. The clock genes present newlinein ovarian follicles coordinate the environmental clock and ovarian events. The newlinetiming of secretion of gonadotropic hormone and ovulation is based on the newlineinformation of light received by SCN. newlineThe disruption of clock genes due to photoperiodic stress is linked to disorders newlinelike polycystic ovarian syndrome (PCOS). PCOS is characterized by alterations newlinein androgen levels, leading to an increased LH/FSH ratio and anovulation. newlineAdditionally, free radicals generated by photoperiodic stress