Aneuploidy in male germ cells induced by alcohol ingestion

Nondisjunction induced by ethanol in Drosophila melanogaster females

The effect of ethanol on chromosomal segregation was investigated in Drosophila melanogaster females homozygous for a structurally normal X chromosome marked with the recessive mutation yellow (y/y). For chronic treatments the females were kept from eclosion in food supplemented with 10% or 15% (v/v) ethanol, mated 24 or 48 h later to wild-type males and brooded in freshly prepared ethanol food. For the acute treatments 24- or 48-h-old females were exposed for 60 min to a 75% (v/v) ethanol solution by means of soaked tissue paper placed at the bottom of regular culture vials and brooded daily after mating. The results obtained show that: (1) both treatments significantly increased the frequency of X-chromosome nondisjunction; (2) after acute treatment this effect declined in later broods; (3) the yield of malformed flies in the progeny of acutely treated females was significantly higher than control values and also declined in later broods; (4) ovary analysis showed that chronic ethanol treatments caused a cessation of egg production. The induction pattern of nondisjunction and malformed flies is interpreted as giving support to the assumption that these effects may result from a direct action of ethanol. Ethanol toxicity was assessed by exposing females of different ages to a 50% or a 75% (v/v) solution for 60 min and counting the surviving flies 24 h later. The surviving fraction decreased steeply from 1-day-old (100%) to 5-day-old females (1.8%). It is suggested that toxicity may have been due to the action of a metabolite of ethanol, probably acetaldehyde.

A comparative study on ethanol and acetaldehyde as inducers of chromosome malsegregation in Aspergillus nidulans

The activity of ethyl alcohol and acetaldehyde on mitotic chromosome segregation and conidial germination in Aspergillus nidulans was studied. Ethanol effectively induced malsegregation in a narrow range of concentrations (4.5-5.5%, v/v) and was inactive at doses which arrested conidial germination (above 6%). The same bell-shaped dose-response curve was shown by the spindle poison chloral hydrate, which was active in the range 6-10 mM. Acetaldehyde displayed a diphasic dose-response curve. Genetic analysis of induced segregants suggests that the disturbance of chromosome segregation is the primary genetic effect at low doses (0.025-0.037%), while at higher doses (above 0.1%), when growth was arrested, chromosome damage was primarily induced. The same pattern of segregants was produced by hydroquinone, a substance which indirectly affects chromosome segregation in A. nidulans. These differences in the genotoxic profiles of ethanol and acetaldehyde suggest that the effect exerted by ethanol on A. nidulans mitosis is not dependent on its conversion into acetaldehyde. In the absence of an effect of ethanol on in vitro polymerization of tubulin (actively inhibited by acetaldehyde at doses above 0.075%), a direct effect of ethanol on cell membranes is hypothesized. Comparison of the inhibition of growth and the effectiveness in aneuploidy induction displayed by ethanol, methanol, n-propanol and n-butanol demonstrates, in fact, a fair correlation with logP, a descriptor of lipophilicity related to the partitioning of compounds in biological membranes.

Paternal and maternal alcohol consumption: effects on offspring in two strains of rats

Long-Evans and Sprague-Dawley male rats were given liquid alcohol diets containing 35%, 17.5%, or 0% ethanol-derived calories (EDC). The latter two groups were pair fed to the higher alcohol diet group. A fourth group received lab chow and water ad libitum to assess the role of paternal undernutrition associated with alcohol consumption. After three or four weeks of diet consumption, these males were bred to females of the same strain. Pregnant females were divided into similarly treated alcohol groups and were fed these diets beginning on gestation Day 8, thus creating a factorial study with strain, paternal, and maternal alcohol consumption as main factors. Paternal alcohol consumption was associated with decreased litter size, decreased testosterone levels, and a strain-related effect on offspring activity. Offspring activity decreased for those sired by 35% and 17.5% EDC Long-Evans fathers. Activity also decreased for offspring sired by 17.5% EDC Sprague-Dawley fathers but increased for those sired by 35% EDC fathers. Paternal alcohol consumption did not affect postnatal mortality or passive avoidance learning of offspring. Maternal alcohol consumption was associated with lower birth weights, lower offspring weights at weaning, increased postnatal mortality, and poorer passive avoidance learning. However, offspring activity was not affected. In a separate study, levels of alcohol in the testes were found to be somewhat, but not significantly, lower than blood alcohol levels. DNA taken from sperm of Long-Evans males consuming alcohol, migrated farther under pulsed field electrophoresis than DNA from control fathers, suggestive of an alcohol-related effect on sperm DNA.

Ethanol accelerates acrosomal loss in human spermatozoa

The effects of ethanol on the loss of the human sperm acrosome, as determined by the chlortetracycline fluorescence assay and by indirect immunofluorescence assay, were assessed over 6 hours during incubation at 37 C in BWW medium containing 0 to 250 mM ethanol. Both assays gave the same results. At the end of 6 hours, 48 +/- 6% acrosomal loss was found in samples in 250 mM ethanol compared with 4 +/- 1% in the absence of ethanol. After 0.25 hour, the first time point chosen for sampling, the spermatozoa in 250 mM ethanol showed 23 +/- 3% loss of acrosomes compared with less than 1% in the absence of ethanol. Ultrastructural studies revealed that the ethanol-treated spermatozoa showed complete acrosomal loss as well as loss of the equatorial segment. No examples of the vesiculation characteristic of the physiologic acrosome reaction were found in the 150 cells examined. Calcium is required for the ethanol-mediated acrosomal loss: omission of Ca2+, addition of 2 mM EGTA, or 0.2 mM verapamil blocked the effect. Ethanol induced a dose-dependent efflux of cholesterol from human spermatozoa, but the ethanol-induced acceleration of acrosomal loss occurred to the same extent in the presence of cholesterol microdispersions that prevented this efflux. The loss of the equatorial segment, which is necessary for egg penetration, during ethanol-induced acrosomal loss would explain the known effect of ethanol in inhibiting, rather than enhancing, the penetration of zona-free hamster eggs by human spermatozoa.

Effects of paternal alcohol consumption on pregnancy outcome in rats

Male rats were divided into 3 groups and were given ad lib access to a liquid alcohol diet containing 35% ethanol derived calories (EDC) or were pair-fed with an isocaloric control diet, containing 17.5% or 0% EDC, for a minimum of 52 days. A fourth group was fed rat chow ad lib. Males were then mated with non-treated females. Males consuming alcohol did not differ in sexual behavior but were less fertile and sired offspring that were significantly less active than controls and the effects on activity were dose-related. Females sired by males consuming alcohol also performed worse in a two-way shock avoidance learning task although differences in this task were not dose-related. There were no significant effects, however, on body weight of offspring at birth or at 21 days of age or on other behavioral measures such as spontaneous alternation or passive avoidance learning.

Hypoploidy and hyperplasia in the developing brain exposed to alcohol in utero

Prenatal effects of acute maternal alcohol ingestion on chromosome segregation and mitotic frequency in the brain cells of the fetus were evaluated in mice by direct chromosome and mitotic counts and by flow cytometry. Fetuses were exposed to acute transplacental doses of alcohol for 4 days and killed on the fifth day. Those litters in which the fetuses were developed to the equivalent of normal 16th-17th-day gestation age were analyzed. A marked increase in the number of hypoploid metaphases was observed in direct proportion to the dose ingested by the mother. An over 30% increase in hypoploidy over controls was measured in the fetuses exposed to the highest dose. Counts of mitotic cells showed an over tenfold increase in the mitotic index of the fetal brain exposed to alcohol. Flow cytometric measurements of DNA content in isolated fetal brain cell nuclei showed a shift from a single G0/G1 peak in controls to a bimodal G0/G1-G2 + M distribution in alcohol-exposed fetuses of the same developmental age.

Concomitant mutagenicity of ethanol and x-ray irradiation in the mouse male germ cells

The mutagenic effect of ethanol and x-ray irradiation on the male germ cells was investigated in the mouse. The meiotic micronuclei in the testis were recorded and the abnormalities in the epididymal sperm heads were counted. The number of micronuclei in early spermatids did not differ in the ethanol-exposed groups from that of their control groups at the end of 5 week ethanol diets. However, in the mice irradiated with a dose of 0.5 Gy, there was a statistically significant (p less than 0.01) difference in micronucleus induction between the groups of different ethanol exposure levels. No statistically significant differences were found in the numbers of abnormal sperm heads immediately after the diet or 25 days, 5 weeks and 10 weeks after the cessation of the diet. However, sperm abnormality frequencies were elevated at 5 weeks after 4 and 6% (v/v) ethanol diets and at 25 days after the 6% diet. The results suggest that ethanol is co-mutagenic with x-rays in the mouse male germ cells. Ethanol alone showed also a tendency to be mutagenic in the sperm abnormality test. The stage and mechanism of action of ethanol is discussed.

Glycolysis in the mouse uterus during the early post-implantation stages of pregnancy and the effects of acute doses of ethanol

The objective of this study was to assess the possibility that, in mice, alcohol interferes with uterine glycolysis to influence indirectly embryonal development. Glycolysis was found to be a major metabolic process in the mouse uterus and its pattern of activity changed during post-implantation pregnancy between days 5 and 9. This was evidenced by changes in glycolytic enzymes and intermediates, and in the capacity of endometrial preparations to consume oxygen and produce lactate during incubation in vitro. The intraperitoneal administration of ethanol at 3.0 and 6.0 gm/kg body weight, but not at 1.5 gm/kg body weight, on day 9 of pregnancy modified glycolysis in the uterus after 2 hours, resulting in significant changes in the rates of accumulation of glucose, glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-diphosphate, and citrate. These effects were not mediated by changes in redox state, since the ratio of lactate to pyruvate remained unchanged after injection of ethanol. Citrate was considered to be a major factor involved both in the regulation of uterine glycolysis and in the ethanol-induced alterations in the levels of hexose phosphates. The elevated levels of uterine glucose registered after treatment with ethanol were related to an acceleration of glycogen degradation in the liver and not in the uterine endometrium. The results suggest that part of the adverse action that these doses of ethanol exert on embryonal development stems from indirect effects that involve uterine functions relating to the nurture of the conceptus via glycolysis.