Effects of Ovarian Steroid Hormones on Histochemically Demonstrable Lipids in the Rat Uterine Epithelium

Abstract

Histochemical studies showed that during the rat oestrous cycle, uterine epithelial lipids were at their highest levels during dioestrus and pro-oestrus. In ovariectomized mature animals given oestradiol-17\g=b\, either by itself or in combination with medroxyprogesterone acetate, neutral lipids and unsaturated lipids were below control levels, while phospholipids were increased. Medroxyprogesterone acetate, however, increased levels of neutral lipids and unsaturated lipids, and decreased phospholipids. It is suggested that during the oestrous cycle of the rat, high concentrations of uterine epithelial lipid during late dioestrus and pro-oestrus reflect the increased plasma progesterone of early dioestrus acting in a low plasma oestrogen environment.

Fructose metabolism in the rat endometrium under normal and experimental conditions

“…), were maintained in an air-conditioned, temperature-(20-21°C) and light-(from 07.00 to 19.00 hours) controlled room. Vaginal smears were taken daily and recorded as described previously (Boshier & Holloway, 1973). Females were used only after the completion of two regular 4-day cycles.…”

Hormonal Influence on Uterine Lipids

“…However, uterine lipids were suggested to be derived from the Fallopian tubes, or circulatory system or by biosynthesis in the uterus itself (1). Even though much work has been concentrated on blood cholesterol under the influence of oestrogen or contraceptive pills, elaborate investigations on the various classes of lipids in the uterus with reference to different sex steroids except oestrogens (18,19) are not forthcoming. In the present study an attempt has been made to concentrate on the effect of oestrogen, oestrogen plus progesterone or progesterone alone on the uterine lipid metabolism.…”

Effects of the rat blastocyst on neutral lipids and non-specific esterases in the uterine luminal epithelium at the implantation area

“…The periodic variations in concentrations of neutral lipids result from increased non-specific esterase activity in the uterine epithelium caused by increasing levels of circulating oestrogen (Boshier & Katz, 1975). This communication reports the results of histochemical investigations of the effect of the blastocyst on neutral lipids and nonspecific esterases in the uterine epithelium at the implantation site.Mature virgin female rats of a hooded strain were maintained under normal animal house condi¬ tions as has been described (Boshier & Holloway, 1973). After two complete 4-day oestrous cycles, females were caged, usually at the following metoestrus, with males of proven fertility and the day the copulation plug or spermatozoa in the vaginal smear were found was recorded as Day 1 of pregnancy.…”

“…Triglycerides are the principal components of neutral lipids, and these compounds vary in quantity and intracellular distribution within the rat uterine epithelium during the oestrous cycle (Boshier & Holloway, 1973). The periodic variations in concentrations of neutral lipids result from increased non-specific esterase activity in the uterine epithelium caused by increasing levels of circulating oestrogen (Boshier & Katz, 1975).…”

“…Mature virgin female rats of a hooded strain were maintained under normal animal house condi¬ tions as has been described (Boshier & Holloway, 1973). After two complete 4-day oestrous cycles, females were caged, usually at the following metoestrus, with males of proven fertility and the day the copulation plug or spermatozoa in the vaginal smear were found was recorded as Day 1 of pregnancy.…”