Immunohistochemical demonstration of renin in the endometrium.

Increased levels of plasma prorenin, an inactive form of renin, and renin were demonstrated during normal menstrual cycles and the source of this enzyme was thought to be the ovary. To demonstrate that endometrium may produce renin, an immunohistochemistry for human renin was used in this study. Renin containing cells either in the glands or in the stroma were demonstrated in 5 of 20 sections of endometria. Since a product of renin, angiotensin II has been found to have angiogenic properties and may have a role in repair process, we postulate that renin containing cells present only in proliferative phase endometria may be involved in repair or regeneration of the endometrium.