Distribution of the vanilloid (capsaicin) receptor type 1 in the rat ovaries on different sexual development period

Abstract

Vanilloid receptor (VR1) is expressed in the central nervous system as well as in various non-neuronal cells (mast cells, keratinocytes and epithelial cells). The VR1 expression in rat ovaries according to the sexual development period was investigated in the present study by immunohistochemistry. Ovaries were removed after euthanasia from pubertal female Sprague Dawley rats (42 day old), from post-pubertal females (56 day old) and from adult females (70 day old) (n = 10 in each group) and tissue samples were processed for conventional histology and for immunohistochemistry using the Streptavidin-Biotin Peroxidase method and a rabbit polyclonal anti-VR1 primary antibody. Serum gonadotropins and sexual steroid concentrations were determined in parallel by commercial ELISA kits. Whatever the sexual development state, the VR1 expression was evidenced in the cytoplasm of various ovarian cell types (granulosa, interstitial, theca and luteal cells) with a moderate intensity albeit the protein accumulation was lower in the theca follicle cells. Furthermore the VR1 ovarian expression seems to be independent from a hormonal control. These results demonstrate the constitutive VR1 expression in rat ovaries.