Leptin Receptors in Galea Spixii

The spix’s yellow-toothed cavy, (Galea spixii), is a small rodent found in South America. Due to its
adaptability, prolificity and low dietary requirements, the cavy has significant social importance, as it
represents a source of unconventional and low-cost animal protein mainly for low-income
communities Studies aimed at understanding the reproductive dynamics of these animals have a
significant contribution to the multiplication and preservation of the species. Leptin has been credited
with importance in both energy homeostasis and reproduction. Leptin actuation occurs by binding to
specific membrane receptors (Ob-Rb) The Ob-Rb receptor signals from the JAK-STAT pathway,
accounting for most of the biological effects of leptin including oocyte maturation in vertebrates. The
mechanism of action of leptin in the ovary is explained in several ways, one of them being its direct
action on ovarian secretory activity, the other acting on angiogenesis and also on follicular apoptosis.
This hormone also acts indirectly as activator of the neuroendocrine system, exerting its effects on the
hypothalamic-pituitary gonadal axis. In addition to stimulating GnRH, leptin acts directly on the
pituitary by stimulating FSH and LH secretion. Leptin receptors were detected in prey ovaries. They
are located in granulosa cells, teak cells, oocyte, stromal cells, endothelial and perivascular cells, as
well as the corpus luteum. Differences were observed in the intensity of reaction to the 3,3'-
Diaminobenzidine (DAB) chromogen, used in the immunohistochemical technique, in relation to the
ovary structures of Galea spixii. The intensity of the teak cells and the oocyte were the strongest, the
stroma and the large luteinic cells showed a medium staining (moderate reaction). The results
demonstrate the presence of leptin receptor immunostaining by immunohistochemistry in the oocyte,
teak and granulosa cells at all stages of follicle development, the corpus luteum in both small and
large lutein cells, endothelial and perivascular cells as well as of the ovarian stroma of prey (Galea
spixii). With different intensities between the ovarian structures being observed intense marking in the
oocyte and teak cells, moderate in the stroma and large luteinic cells, weak for the other cell types
mentioned. Based on this, it is possible to suggest that leptin plays a fundamental role in the
reproduction of this species.