• oestrogen receptor α;
  • neuronal nitric oxide synthase;
  • clitoris;
  • mice


To study the presence of oestrogen receptors (ER) and neuronal nitric oxide synthase (nNOS) in the mouse clitoris.


A series of sections of the pelvic area, including the preputial glands and clitoris, of 10 mice were assessed by immunocytochemical studies specific for ER-α and -β, and nNOS; selected sections were also stained with Masson’s trichrome.


ERα was detected in the epithelium of the gland of the clitoris, and in the glandular tissue, preputial and apocrine gland. ERα was detected in the nuclei of stromal cells around the cavernous tissue and near the epithelium of the clitoris. Cytoplasm ERα was detected in a few cells in an area ventral to the clitoral gland. There was also nuclear staining in the connective tissue cells surrounding the clitoris. Very light ERβ immunostaining was detected in the clitoris and in the tissue related to it. There were some cells with nuclear staining in the vessels of the cavernous tissue of the clitoris. nNOS immunostaining was detected in the clitoris, the preputial gland and the connective tissue.


ERα and β isoforms, and nNOS, are present in the clitoris and preputial glands of female mice in different cellular locations and with differing levels of receptivity. Functional studies would further elucidate the role of receptor functions and their relationship to the neuronal expression of NO.