Effects of pinealectomy on circadian rhythm of asprosin hormone

Circadian rhythms are biological processes evolved to adapt organisms to environmental cycles. The pineal gland and melatonin play a central role in regulating these rhythms. The relationship between melatonin and asprosin, a newly discovered adipokine, as well as its circadian rhythm, has not yet been fully elucidated in the literature. This thesis aimed to investigate the circadian rhythm of the asprosin hormone, to reveal potential changes in this rhythm following pinealectomy, and to understand the possible correlations between asprosin and other hormones such as corticosterone, insulin, leptin, ghrelin, TSH, and GH. In the scope of this study, experimental animals (Sprague Dawley) were used to investigate the circadian rhythm of the asprosin hormone, and pinealectomy was performed on these animals. Pinealectomy, sham, and control groups were established with 12 animals in each group. The pinealectomy procedure was conducted using a stereotaxic device, and the groups were divided into morning and evening subgroups in accordance with the experimental protocol. Following the recovery period after pinealectomy, blood samples were collected from the animals in each group at 07:00 (morning) and 19:00 (evening), and the levels of asprosin and other hormones were measured using the ELISA method. Statistical analyses of the data were performed using the GraphPad Prism software, and the level of significance was set at p ≤ 0.05. At the end of the study, it was revealed that the asprosin hormone possesses a natural circadian rhythm and that this rhythm is affected by pinealectomy. Additionally, the impact of melatonin deficiency on the correlations between asprosin and other hormones was emphasized. This study clarified that the asprosin hormone operates through a mechanism integrated with circadian rhythms and that the pineal gland plays a critical role in this regulation. The findings obtained in this study represent a significant step toward a deeper understanding of the role of the asprosin hormone in circadian biology and provide an essential foundation for future studies in this field. Keywords: Asprosin Hormone, Circadian Rhythm, Pinealectomy