AB144. Histological structures of female genital tissues from angle of the entry of topical drugs

OBJECTIVE: Genital skin is composed of three tissue layers including epidermis, dermis and hypodermis. There are limited histologic and morphologic data concerning the skin of female genital erectile tissues. Knowledge of the histology of female genital erectile tissue is important to the development of safe and effective drug delivery system with topical vasoactive agents for management of female sexual arousal disorder. The aim of this study was to determine the structural and morphological components of various aspects of the external female genital erectile tissue to evaluate the entry of topical drugs for treatment of female sexual arousal disorder. METHODS: Female genital erectile tissues including glans clitoris, labia minora and labia majora were sampled from 20 female cadavers by punch-biopsy (2-3 mm diameter, 5-8 mm long). The tissues were fixed in formalin to be embedded in paraffin, and cut as 12 mm transverse sections, which were stained with haematoxylin and eosin. Thickness of epidermis and dermis, keratin-layer in epidermis, skin appendage in dermis and adipose tissue density in dermis and hypodermis was evaluated. RESULTS: Epidermis of the glans clitoris was thin compared to general skin area but thicker than other genital tissues. Thickness of the Rete ridge of glans clitoris was also thicker than other genital tissues. However, thickness of dermis and hypodermis was much thinner than other genital tissues. Skin appendages such as hair, sebaceous gland and sweat gland and adipose tissue were observed in labia minora and majora but not in glans clitoris. Blood vessels were abundant in all three genital tissues. Hypodermis in labia minora and majora was fatty but not in glans clitoris. In the glans clitoris, no tunica separating hypodermis from the corpus spongiosum (labia) was observed. Also skin of glans clitoris with thin epithelium was easily connected to erectile tissue through loose connective tissue in hypodermis. CONCLUSIONS: Topical delivery of vasoactive drugs of low molecular weight to the glans clitoris might reach the labia but not likely the clitoral cavernous tissue. Further research in the vascular system of the female genitals will be required.