Delayed gastric emptying in conscious male rats following chronic estrogen and progesterone treatment

Abstract

Several clinical observations and animal experiments have led to speculation concerning the possible effects of pregnancy and pregnancy-associated sex steroids on gastrointestinal function. It was reported that estrogen increases intestinal contractile activity, while progesterone or the combination of estrogen and progesterone decreases it. In order to measure gastric emptying, a methylcellulose test meal was given orally into the stomach of conscious rats. In progesterone-treated rats, at the dose of 0.2 mg/kg, gastric emptying was not significantly different from that of the control, but it was found to be significantly delayed at the dose of 10 mg/kg (P < 0.05). Estrogen treatment at doses of 20 micrograms/kg and 600 micrograms/kg significantly delayed gastric emptying, when compared with controls (P < 0.001). Combined therapy of estrogen and progesterone induced a significant delay in gastric emptying rate compared with the control group (P < 0.001). In the animals with pseudopregnancy treatment (100 micrograms/kg estrogen+ 15 mg/kg progesterone; 7-12 days) the gastric emptying rate was significantly different from that of the control (P < 0.05). We conclude that both estrogen and progesterone exert inhibitory effects on gastric emptying, and this may account for the disturbances in gastrointestinal function that pregnant women frequently experience.

Immunolocalization of estrogen receptor alpha and beta in gastric epithelium and enteric neurons

“…The ER antisera (ER-21) used in this study showed nerve fiber staining in the lateral habenula (Wagner et al 1998) and ER immunoreactivity (PA1-310) in nerve fibers has been reported in regions of the hippocampus and lateral septum (Li et al 1997). Localization of ER proteins in enteric neurons is provocative in the light of studies showing that estradiol administration delays gastric emptying in Ovx and male rats (Chen et al 1995, Coskun et al 1995. Our results suggest that ER and ER could mediate estrogenic effects on gastric motility through the enteric nervous system.…”

Nutrition and human health from a sex–gender perspective

“…Additionally, several sex-gender related differences in colorectal cancer are reported in Section 4.1. Estrogens inhibit gastric emptying (Coskun et al, 1995;Wu et al, 2002), whereas the effects of progesterone vary depending on concentration: low concentrations increase gastric emptying in rats while high concentrations inhibit emptying (Chen et al, 1995;Liu et al, 2002). Preclinical findings have implicated gonadal hormones in the motor activity of the gastrointestinal tract (Bond et al, 1994;Ryan and Bhojwani, 1986).…”

Effects of progesterone on gastric emptying and intestinal transit in male rats

“…We reported that administration of estrogen inhibited the rat gastric emptying and intestinal transit while P enhanced the gut motility [7] . The effects of E were testified by other scholars while the inhibitory effect of P was observed [8] . Oxytocin (OT) is also a hormone related to pregnancy, and its plasma concentration is higher during the late phase [9,10] .…”