Substance P in obstetrics and gynecology.

The occurrence and distribution of the neurohormone substance P in the urogenital tract suggest a role for substance P in regulation of blood flow, smooth-muscle activity, and sensation. The distribution and pharmacologic effects of substance P in the brain suggest an involvement of substance P in regulating the release of gonadotropins and prolactin from the pituitary and in the gonadal-hypothalamic feedback. As substance P is also present in endocrine-like cells of the diffuse endocrine system in the urogenital tract, it may serve as a tumor marker for carcinoid and related tumors, particularly in the ovary and the uterine cervix. This review is limited to the distribution and effects of substance P in the female genital tract and its relevance in female reproduction.