There are still many areas in the field of female sexual physiopathologies that remain to be fully studied, among which are disturbances of the excitation phase, particularly the hemodynamics of the clitoral corpora cavernosa. Low levels of estrogens and vascular risks lie at the base of female sexual arousal disorders.

The aim of our study was to investigate the ultrastructure of the clitoral cavernosal tissue in healthy women and those affected by metabolic and hormonal pathologies.

Recent data show the presence of nitric oxide synthase in the clitoral tissue, suggesting that nitric oxide could be involved in the mechanisms of clitoral tumescence. Moreover, the presence of type 5 phosphodiesterase activity in clitoral tissue has been hypothesized.

Informed consent was obtained from the 24 women enrolled in the study. Five were diabetic premenopausal women, and 8 were naturally post menopausal and 6 surgically post menopausal women affected by HSDD. They all underwent a micro-biopsy of the clitoral body by means of fine needle aspiration under total anesthesia during gynaecological operation for stress urinary incontinence. Five health women undergoing surgically procedures for benign gynaecological pathology were considered as control group. The tissue removed was fixed in Karnowskiʼs liquid and underwent ultrastructural analysis with standard procedures.

Histomorphometric studies have shown that there is a correlation between age and smooth muscle fibers of the clitoral corpora cavernosa due to an increase of connective tissue. In the clitoris there is also a correlation between large diameter thin-walled vessels and smooth muscle fibrocells(SMF), which make up the majority of the cellular elements of the concavity.

In health premenopausal women there are extensive bundles of smooth muscle fibrocells SMF, seen both transversely and longitudinally; the SMF have regular borders, regular nuclei with dense chromatin and evident nucleoli. The cytoplasm includes contractile microfilaments and dense bodies. The cell borders do not have continuous basal membranes(BM) and electro-ionic junctions of the “tight” type. The SMF, in all pre menopause subjects, are isometric with regular borders, having a homogeneous distribution of the microfilaments and dense bodies. The basal membranes are regular with a constant thickness, rarely reduplicate. The blood vessels are thin-walled, made up of a flattened endothelial layer and by an incomplete layer of pericytes, a close association with the interstitial SMF is observed, which, with the pericytes, form tight junctions. The vascular lacunae are particularly interesting, having a single line of flattened epithelial cells with a cytoplasm relatively poor in organules, resting on continuous BM. The SMF have a direct relationship with the vascular lacunae, giving rise to an anatomical-functional complex comparable to that of the corpora cavernosa of the penis.

In diabetic women, the SMF of the BM and the vascular lacunae are notably thickened.

In natural post menopausal subjects the general arrangement is maintained, and only rarely is there a discrete thinning of the SMF, which can, in places, have an irregular border. The concavity, made up of isometric collagen fibers that can be poorly cohesive and moderately thickened in post menopausal subjects.

In surgically postmenopausal women, clitoral tissue is reduced; the SMF have irregular distribution of the microfilaments and borders. The blood vessels are riduced, and the vascular lacunae have not relationship the SMF. Transdermic testosterone therapy of surgically postmenopausal women affected by HSDD seems to also act at the level of the clitoral tissue. In fact, the ultrastructure of the clitoral corpora cavernosa has features almost identical to those found in pre menopausal women.

We hope the electronic microscopic study of the clitoral cavernosal tissue can give similar information to that recorded above, and can be used as an additional tool for the diagnosis, prognosis and therapeutic orientation of female sexual dysfunctions.