Study On Alcohol Consumption Induced Hyperprolactinemia Increase In Female Rats And Their Progency And The Mechanism

Part 1:Effects of alcohol on the serum prolactin level, pituitary wet weights in female ratsObjective To discover the effect of alcohol on the serum prolactin (PRL) level and pituitary wet weights in female rats, understand the correlation between the alcohol concentration and the rats age and serum prolactin (PRL) level change and pituitary hyperplasia, and explore the relation between alcohol consumption and hyperprolactinemia (HP).Methods 1. Forty grown female SD rats of the same age were randomly divided into three alcoholic groups and one control group, ten in each group.10%,20% and 30% ethanol were administered to three alcoholic groups respectively for 4 weeks (in 5 rats) and 8 weeks (in 5 rats) via gastrogavage; the control group was pair-fed on distilled water.2. 20% ethanol was administrated to thirty female SD rats aged four, six and eight weeks respectively for 4 weeks via gastrogavage, and the rats in the control groups were pair-fed on distilled water.3. The serum prolactin levels were detected using radioimmunoassay, the pituitary wet weights were measured, the correlation between the alcohol concentration and the rats age and the serum prolactin level and the pituitary wet weights was analysed. Results 1. The serum prolactin levels and the pituitary wet weights in the group of 30% ethanol were significantly higher than that in other three groups after ethanol intake via gastrogavage for 4 weeks; the serum prolactin levels and the pituitary wet weights in the 10% and 20% ethanol groups were obviously higher than that in 30% ethanol group and the control group after alcohol consumption via gastrogavage for 8 weeks. The comparison made in the same group showed that the serum prolactin levels and the pituitary wet weights in the 10% and 20% ethanol groups after 8 weeks of alcohol consumption were remarkably higher than that in the same groups after 4 weeks of alcohol consumption; the serum prolactin levels and the pituitary wet weights in the 30% after 8 weeks of alcohol consumption were significantly higher that than in the same group after 4 weeks of alcohol consumption. The aforesaid differences were statistically significant, P<0.05.2. After 4 weeks of alcohol consumption with the same concentration,4-week-old rats presented significantly higher serum prolactin levels and the pituitary wet weights compared with respective control groups; while, there were no statistical significances between the serum prolactin levels and the pituitary wet weights in 6-week-old and 8-week-old rats. P>0.05.Conclusion 1. Alcohol consumption can cause change in the serum prolactin level of female rats which depends on ethanol concentration and doses:Higher alcohol concentrations could increase the serum prolactin level within a relatively short time. Long-term consumption of lower alcohol concentrations may greatly elevate the plasma prolactin level.2. Long-term heavy alcohol consumption may lead to the pituitary dysfunction of secreting the prolactin.3. Compared with adult rats, a increased serum prolactin level could be more easily caused by alcohol consumption in juvenile rats. Part 2 The Effect of High Alcohol Intake During Pregnancy on the Serum Prolactin Level and Pituitary Wet Weights of the Rat ProgenyObjective:To discuss the effects of high alcohol intake during pregnancy on the serum prolactin level and the pituitary wet weights of rat progenyMethods:Six grown female SD rats of the same age were randomly divided into one alcoholic group and one control group, three in each group.20% alcohol was administrated to the rats in the alcohol group via gastrogavage (2g/kg per day) from the first day of pregnancy (P1) to pre-delivery. The rats in the control group were given distilled water in the same period. The offspring rats were fed for 4 weeks after birth, then half of the rats in each group were sacrificed at random. The remaining rats were fed continually for another 4 weeks before being killed. The prolactin levels of the rats in each group were detected using radioimmunoassay, and their pituitary wet weights were measured.Results:1. With 4-week-old offspring:the pituitary wet weights in the alcohol group were significantly higher than that in the control group (P<0.05), while there was no statistical significance in the differences between the PRL levels in the two groups (P> 0.05); 2. With 8-week-old offspring:the pituitary wet weights and the PRL levels of the rats in the alcohol group were significantly higher than those in the control group (P <0.05).Conclusion:High alcohol intake during pregnancy in rats could reduce progeny serum prolactin levels and increase the pituitary wet weights. Alcohol may cause a increased blood prolactin level by stimulating the pituitary hyperplasia. Part 3 Study on Mechanism of the Serum Prolactin Increase in Female Rats Caused by Alcohol ExposureObjective:Study on mechanism of a increased serum prolactin in female rats by alcohol exposure.Methods:Forty grown female SD rats of the same age were randomly divided into one alcoholic group and one control group, twenty in each group. The rats were implanted with intragastric cannulae. The alcoholic group was fed on 2ml of 20% ethanol,2 times daily for 8 weeks. The control group was pair-fed on distilled water. The serum prolactin levels were detected, the pituitary wet weights were measured, and the pituitary gland cell proliferation were detected using immunohis-tochemistry. Norepinephrine, dopamine,5-HT, r-aminobutyric acid, glutamate in hypothalamus homogenate were assayed using coulomb array electrochemistry high performance liquid chromatography(HPLC) and the comparisons were made.Results:1. The serum prolactin levels, the pituitary wet weights in the experimental group were significantly higher than that in the control group P<0.05.2. The hypothalamic homogenate dopamine,5-HT, r-aminobutyric acid in the experimental group were significantly lower than those in the control group. While, the glutamate acid concentration in the experimental group was significantly higher than that in the control group, P<0.05. There was no significant difference between noradrenaline concentrations in the two groups, P>0.05.3. The Ki-67 expression in the experimental group was remarkably higher than that in the control group, P<0.05.Conclusion:Alcohol increases the serum prolactin, and the mechanism is probably associated with:1. the pituitary prolactin cell proliferation 2. a decreased secretion of prolactin release inhibiting factor (PIF) such as dopamine,5-HT, r-aminobutyric acid by the hypothalamus after alcohol stimulation, and a increased secretion of prolactin releasing factor (PRF), such as glutamate by the hypothalamus after alcohol stimulation.