Effects of oestrone and progesterone on collagen and ascorbic acid content in the endometrium and myometrium of the rat.

Abstract

Department of Physiology and Cell Biology, University of Kansas, Lawrence, Kansas 66045, U.S.A. Although endometrial progestational differentiation appears to be regulated precisely by ovarian steroid hormones (Yochim & DeFeo, 1963), little evidence is available concerning the hormonal effects on uterine collagen during the preimplantation stages of progestation. The present study was undertaken to examine the effects of oestrone and progesterone on endometrial and myometrial collagen content in the rat during the oestrous cycle and early pseudopregnancy. Hydroxyproline content was used as an index of extractable collagen, and ascorbic acid was also measured, since this vitamin has been implicated in the hydroxylation of proline during collagen production (Gould, 1958). Adult female Holtzman rats (200-300 g) were caged individually in temperature (23 ± 1°C)- and light-controlled (14 hr light/24 hr) quarters. Animals were allowed unrestricted access to food and water, and vaginal smears for each rat were recorded daily for at least