Effects of ethanol on reproduction and arterial hypertension in spontaneously hypertensive and normotensive rats: a preliminary communication

Hydrocephalus following prenatal exposure to ethanol

Pregnant rats were administered a liquid diet containing 5% (w/v) ethanol between gestational days 10 and 21, and the brains of nine offspring were examined at 8 weeks of age. Two ethanol-treated offspring showed obvious hydrocephalus characterized by markedly enlarged lateral ventricles. Most of the other ethanol-treated rats only showed a slight enlargement of the lateral ventricles. An ethanol-treated offspring showed no neuropathological signs of hydrocephalus. Histological observation of the hydrocephalic brains revealed dilation of the lateral ventricles, loosely bundled corpus callosum, hypoplasia of the septum and fimbria, and thinning of the cerebral cortices. There were no differences in the shape of the third ventricle and aqueduct between hydrocephalic and non-hydrocephalic rats. Ectopic cell clusters were found on the surface of the lateral ventricle and in the interventricular foramen in ethanol-treated rats with hydrocephalus. However, leptomeningeal heterotopias were found on the cortical surface in ethanol-exposed rats independently of whether or not they showed hydrocephalus. Thus, heterotopias within the ventricles may be related to the genesis of hydrocephalus following prenatal ethanol exposure. However, whether they could be a direct cause of the hydrocephalus is uncertain as they seem to be not enough large to block the current of the cerebrospinal fluid. We also examined the expression of L1, a cell adhesion molecule suspected of involvement in the genesis of hydrocephalus after prenatal ethanol exposure, in 1-day-old rats. Western blot analysis using specific antibody against L1 showed no significant change in L1 protein expression in ethanol-exposed rats. These data suggest that L1 protein expression is not affected by ethanol.

Effects of gestational alcohol exposure on the fatty acid composition of umbilical cord serum in humans

This study examined the effects of maternal periconceptional alcohol intake on polyunsaturated fatty acid (PUFA) concentrations in human neonates. The area percentage of each fatty acid in cord blood serum from 12 infants born to control women (who consumed <2 mL absolute ethanol/d) was compared with that of 9 infants born to women whose periconceptional alcohol intake averaged > or = 30mL absolute ethanol/d. Periconceptional alcohol use was associated with a 30% increase in the proportion of docosahexaenoic acid (22:6n-3) in cord blood (3.0% of total lipid in control infants compared with 3.9% in alcohol-exposed infants; P < 0.01). The rise in the proportion of 22:6n-3 was responsible for increases in the ratio of n-3 to n-6 fatty acids and the ratio of long-chain n-3 to n-6 fatty acids (P < 0.055). Examination of the lipid-class fatty acid profile indicated that serum lipid alterations were localized to the cholesterol esters; 22:6n-3 in the cholesterol esters of alcohol-exposed infants increased 54% (P < 0.011) and arachidonic acid increased 55% (P < 0. 005). The relative fatty acyl composition of maternal serum showed a significant increase in 18:0 fatty acids in the alcohol-exposed group (25%, P < 0.005) but there were no changes in the other fatty acids. The increase in the proportion of 22:6n-3 was unexpected but is consistent with the hypothesis that this essential lipid may be conserved selectively. These results imply that the lifelong neurobehavioral and sensory dysfunction in fetal alcohol syndrome and other alcohol-related neurodevelopmental disorders may be due in part to PUFA dysregulation.

Alcohol abolishes the hypotensive effect of clonidine in spontaneously hypertensive rats

This study tested the hypothesis that concurrent ethanol administration attenuates the hypotensive effect of clonidine. Four groups of spontaneously hypertensive rats matched for baseline systolic pressure and body weight were randomly assigned the following treatments: (1) water (control), (2) ethanol, (3) clonidine, and (4) ethanol plus clonidine for 13 weeks. Ethanol was provided in the drinking water as 5% for 1 week, 10% for the next 2 weeks, and 20% from week 4 to 13. Starting from similar baseline systolic blood pressures, the blood pressure of the control group increased 10 to 15 mm Hg over the 13-week treatment period. A similar rise in systolic blood pressure occurred in ethanol-treated rats despite a drastic (40% to 50%, P < .05) reduction in fluid intake. Clonidine (300 micrograms/kg per day) caused a smaller and shorter reduction in fluid intake. The fluid intake of the combined treatment group was similar to that of the ethanol group. Either treatment caused a significant and additive reduction in body weight gain. Treatment-related mortality (20%) occurred only in the combined treatment group by the 12th week. Clonidine elicited a slowly developing hypotensive response (P < .05) that started 2 to 3 weeks after treatment was initiated and lasted throughout the treatment period. Ethanol abolished the hypotensive effect of clonidine and resulted in blood pressure values that were not significantly different from those of the control or the ethanol group. Blood ethanol concentration was similar in the presence or absence of clonidine (5.5 +/- 1.9 versus 6.5 +/- 3 mmol/L).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of ethanol on heart rate and blood pressure in nonstressed and stressed rats

The effect of ethanol on the cardiovascular system (ECG, heart rate, blood pressure) was studied in anesthetized, nonstressed or stressed rats. In anesthetized rats, ethanol showed no effect on heart rate or ECG. In nonstressed rats, ethanol sedated the animals but increased heart rate significantly. This ethanol induced tachycardia seemed the result of a direct stimulation of the sympathetic nerves to the heart. Blood pressure was not significantly affected by ethanol in these nonstressed rats. In stressed rats, marked behavioral excitation and significant increases in heart rate and blood pressure were noted. Ethanol pretreatment calmed the animals considerably during restraint. Ethanol did reduce slightly the stress-induced tachycardia but markedly reduced or antagonized stress-induced blood pressure increases. No major changes in the ECG were noted during these studies with the exception of a few individual animals which showed pathologic ECG responses to ethanol. These data show that ethanol affects cardiovascular functions differently in anesthetized, nonstressed or stressed rats, and that ethanol can significantly reduce or antagonize stress-induced behavioral excitation, tachycardia and hypertension.

Preferential alcoholic embryopathy among contiguous siblings of Long-Evans rats

Ethanol exposure alters sex steroidogenesis and sexually dimorphic behaviors in rodent offspring. Contiguity to siblings of the same or opposite sex in utero also affects steroidogenesis and sexual dimorphism in rodents. The present study with Long-Evans rats shows that maternal exposure to ethanol during the critical period of rodent organogenesis preferentially affects body weights and increases malformations in offspring dependent on their in utero contiguity to siblings of the opposite sex.

Studies on the embryopathic effects of ethanolamine in Long-Evans rats: preferential embryopathy in pups contiguous with male siblings in utero

The embryopathic effects of high doses of ethanolamine were evaluated in pregnant Long-Evans rats during the "critical period" or organogenesis. Ethanolamine was given by gavage at levels of 0, 500, 300, or 50 mg/kg/day (24%, 14.4%, or 2.4% of the LD50 value). Ethanolamine caused dose-dependent increases in intrauterine deaths, malformations, and intrauterine growth retardation. Embryolethality caused by 500 mg/kg of ethanolamine was not random: male pups contiguous to two male siblings (designated mMm) were almost quantitatively replaced by resorptions that were contiguous to two live male pups (designated mRm) (mMm pups constituted 6.7% of control implants and decreased to only 0.9% of group II implants while mRm resorptions increased from 0.3% in controls to 5.6% in group II dams). Intrauterine growth retardation and increases in gross structural anomalies (considered indicative of depressed fetal growth) more severely affected male than female offspring at all dose levels. Pups of either sex who were contiguous to male siblings were more adversely affected than those offspring contiguous to one or more female siblings. As ethanolamine was given prior to the period of greatest fetal growth and fetal sex steroidogenesis, it is suggested that intrauterine levels of female sex steroids (estradiol) enhance fetal repair of cellular damage while testosterone inhibits fetal repair or exacerbates previous embryonic damage by some unknown mechanism. Such interaction furthers the concept that intrauterine position affects the endpoints of developmental toxicity, as expressed at parturition.