AUTHOR=Kwon Ahreum , Eom Ji Young , Lee Woo Jung , Choi Han Saem , Song Kyungchul , Suh Junghwan , Chae Hyun Wook , Kim Ho-Seong 

TITLE=Serum kisspeptin levels mainly depend on ovarian expression of Kiss1 mRNA in female rats

JOURNAL=Frontiers in Physiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2022.998446

DOI=10.3389/fphys.2022.998446

ISSN=1664-042X

ABSTRACT=<p>The hypothalamic kisspeptin/KISS1 receptor system is essential for puberty onset and reproductive development. Although serum kisspeptin might be associated with puberty, its levels, according to developmental stage, and its origin still remain unclear. This study evaluated the changes in serum kisspeptin levels during puberty and the corresponding <italic>Kiss1</italic> mRNA and protein expression in various organs of female rats to identify the source of serum kisspeptin. Tissues from several organs, including the ovaries and anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) in the hypothalamus, were obtained for assessing <italic>Kiss1</italic> mRNA and protein expressions. Serum kisspeptin levels progressively increased with developmental stages until the peripubertal stage. The ovaries showed the highest <italic>Kiss1</italic> expression among the organs examined. Next, we explored the changes in serum kisspeptin levels and hypothalamic <italic>Kiss1</italic> expression in ovariectomized and estradiol-treated ovariectomized rats. Serum kisspeptin levels decreased regardless of estradiol treatment; <italic>Kiss1</italic> expression was enhanced by ovariectomy and estradiol treatment in the ARC, while it was decreased by ovariectomy and enhanced by estradiol in the AVPV, suggesting that serum kisspeptin may be associated with pubertal development and mainly depended on ovarian <italic>Kiss1</italic> expression. Thus, serum kisspeptin levels are associated with puberty and may serve as a downstream marker of ovarian reproductive function.</p>