THE RÔLE OF PROGESTERONE AND LOCAL TRAUMA IN THE PRODUCTION OF CYSTIC-GLANDULAR CHANGES IN THE ENDOMETRIUM AND HYPERTROPHY OF THE MYOMETRIUM

Abstract

Expts. in ovariectomized rats pretreated with [alpha]-estradiol and then chronically treated with large doses of progesterone have shown that if the endometrium of such animals is traumatized, it is gradually transformed into a typical "Swiss cheese endometrium" as the result of cystic hyperplasia of its glands. This change is preceded by deciduoma formation at site of trauma. The myometrium is much thicker in the areas distended by cyst formation than it is elsewhere; this is mainly due to hypertrophy of the individual muscle fibers. The stimulating action exerted by progesterone on uterine muscle cells is increased by the mechanical factor of distention. The possible implications of these observations as regards the hypertrophy of the myometrium during gestation are discussed.