Effect of chronic alcohol consumption on rat uterine spontaneous motility, prostaglandin production and triglyceride metabolism

Effects of low chronic ethanol exposure on prostaglandin E synthesis by preimplantation mouse embryos

Embryo prostaglandin (PG) synthesis plays a role in the modulation of embryo metabolism and viability, and in the beginning of the implantation. The effects of ethanol consumption seem to be mediated at least in part by PGs. Increased PG production of postimplantation embryos is associated with retardation and abnormalities in the gestational period. The aim of this study was to find out the effects of low chronic ethanol ingestion by mice, previous to pregnancy, on the PGE released by in vitro and in vivo derived embryos. Immature females or adult males were treated with 5% ethanol for 30 days. After fertilization and mating, two-cell embryos, morulae and blastocysts were collected. The PGE synthesis and release were measured by radioimmunoassay. PGE production by in vitro derived two-cell embryos from ethanol-treated females was lower than in the control group (P < 0.01). Also, PGE production was reduced when two-cell embryos came from ethanol-treated males (P < 0.01). There were no differences in PGE synthesis by in vitro derived morulae and blastocysts in these groups. Two-cell embryos derived from mating produced lower quantities of PGE when they came from ethanol-treated females mated with control males, as compared to the control group. PGE release by in vivo derived blastocysts from ethanol-treated females was reduced significantly, as compared to the control group (P < 0.01). We conclude that a low concentration of ethanol administered chronically to immature females reduces PGE synthesis and release by two-cell embryos from culture in vitro, and by embryos of days 2 and 4 from in vivo development.

Ethanol and parturition: a role for prostaglandins

A common pattern of birth defects was reported in children born to alcoholic women over 20 years ago. Shortly thereafter the constellation of defects became known as the Fetal Alcohol Syndrome, and reports from around the world served to acknowledge the pervasiveness of the disorder. Simultaneously with the clinical reports, animal models were developed to characterize the full spectrum of the teratogenic effects of ethanol. Not only did these animal models serve to define the actions of ethanol on fetal growth and development at the molecular pharmacological, neuroanatomical, and behavioral level, but unintentionally, they have resulted in renewed scientific interest in the effects of ethanol on pregnancy and parturition itself. The purpose of this review is twofold. First we will consolidate and summarize data from both clinical and basic research that pertains to ethanol and parturition. These data will demonstrate that ethanol consumption during pregnancy results in both delayed as well as premature delivery depending upon the pattern of consumption and timing of exposure. With these data as a background, the second objective will be to present a theoretical case for prostaglandins as possible mediators of ethanol-induced effects on the onset of parturition.

Effect of chronic ethanol consumption on the spontaneous contractions, prostaglandin production, triglycerides and glucose metabolism of uterine strips isolated from pregnant rats and in embryos

The constancy of spontaneous isometric developed tension (IDT) and the metabolism of triglycerides (TGs), U-14C-Glucose and 14C-arachidonic acid (14C-AA) in uterine strips isolated from controls and from chronic ethanol (ETOH) fed pregnant rats were explored. The studies were performed on isolated uterine strips suspended in glucose-containing as well as a glucose-free medium. The spontaneous decrement of IDT as time progressed after tissue isolation and mounting was significantly higher in tissue preparations obtained from pregnant rats drinking 20% ETOH, than the controls. This situation was evident in uterine strips isolated from rats at 10 and at 16 days of pregnancy, both in solutions containing glucose or in glucose-free conditions. On the other hand, uterine strips isolated from control rats at 7, 10 and 16 days of pregnancy exhibited almost no decrement of IDT after 60 min of activity in a solution containing glucose or in a glucose-free medium. The absolute values of TGs in uteri obtained from rats drinking ETOH were significantly greater (p < 0.001) than in non-drinking controls. TG levels did not differ at 0 min (initial or postisolation) to those at 60 min in control uterine preparations obtained from pregnant rats at 7, 10 or 16 days of pregnancy and incubated either in a medium with or without glucose. On the contrary, in strips from ETOH-fed animals isolated on the same day of pregnancy, TG levels determined at 60 min following isolation and mounting were significantly lower, when glucose was present or absent from the suspending solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute effects of a single ethanol injection on in vitro rat uterine spontaneous motility, on uteri prostaglandin production and on tissue metabolism of triglycerides

The acute effects of ethanol (ETOH), injected at 3 g.kg-1i.p. on spontaneous contractions, on prostaglandin (PG) production and on the metabolism of triglycerides (TGs), have been studied in uterine strips obtained from rats at diestrus and suspended in glucose-containing or glucose-free solution. The absolute values of isometric developed tension (IDT: expressed in mg) recorded at 0 time (initial or post isolation determinations) and the frequency of contraction (FC), expressed as the number of contraction cycles during 20 min, were similar for uterine strips from controls and from ETOH treated rats. The uterine IDT and the FC expressed as percent changes from internal controls (0 time values) were explored during 180 min in uteri suspended in glucose medium. The magnitude of IDT decreased, as time progressed, both in controls as well as in ETOH-treated rats. Afterwards, uterine strips from controls exhibited a partial recovery of their contractile activity. This pattern of recovery was not observed in uterine strips from ETOH-treated rats. The uterine IDT, in the ETOH-injected animals after 180 min of activity, were significantly smaller than those of controls. On the other hand, the FC decreased progressively up to the end of the experimental period both in controls as well as in ETOH-treated rats. In glucose-free medium, the IDT of uterine strips from ETOH-injected animals diminished significantly more than controls from 100-180 min following isolation and mounting. In addition, the FC of uterine strips from the ETOH group of rats were significantly smaller than in controls suspended in glucose-free solution.(ABSTRACT TRUNCATED AT 250 WORDS)