Studies on the Formation and Maintenance of the Corpus Luteum

Abstract

Factors favouring the growth of the corpus luteum and secretion of progestational compounds are said to be ‘luteotrophic’ while factors causing luteal regression and diminution of progesterone secretion are generally referred to as ‘luteolytic’. However, luteal tissue maintenance and progesterone secretion may not always be closely associated. For example, corpora lutea persist ‘morphologically’ for relatively long periods of time in hypophysectomized rats, but these corpora do not produce progesterone and can be readily differentiated from truly functional corpora on histological grounds. On the other hand, stimulation of bovine luteal tissue growth by methods described below has almost invariably been associated with an increased total progesterone content of the tissue, and often with an increased concentration, as well. Most studies indicate that luteal tissue contents and ovarian vein blood levels of progesterone are correlated.