Roles Of α7nACh Receptor On The Inhibitory Effects Of Prenatal Alcohol Exposure To RRDA Of Neonatal Rat

Background Alcoholism is one of the factors that affect human’s health. It not only damage to personal physical and mental health, but also has a negative effect to society. Women drinking during pregnancy can severely affect fetal growth and development, such as fetal alcohol syndrome (fetal alcohol syndrome, FAS), and central nervous system disorders is one of its characteristics. The stable basic rhythmic respiration originates in the medullary respiratory center, and the stability of rhythmic respiration is very important for maintaining many of the body’s functions. Central respiratory system diseases, especially the lesion of medullary respiratory center, are common diseases and frequently. encountered disease in the clinical work, and there are more and more abnormal central respiratory induced by alcoholism, therefore, it has a far-reaching significance to study the influence of prenatal alcohol exposure on the function of medullary respiratory center.Objective To explore the mechanism of prenatal alcohol exposure depression rhythmic respiratory discharge activities(RRDA) of neonatal rat medullary slice via down-regulating of a7nicotinic acetylcholine receptor(α7nAChR) by observing the change of RRDA and a7nAChR protein and mRNA expression in neonatal rat medullary slice induced by prenatal alcohol exposure.MethodsHealthy Sprague-Dawley rats were randomly divided into control and experimental groups. Adult rats in control group and prenatal alcohol exposure group were same breeding except the rats in prenatal alcohol exposure group had access to8%(v/v) alcohol solution as sole drinking water for1month before mating and throughout the pregnancy and lactation1. Sprague-Dawley rat (2days) medullary slices was made, and recorded the RRDA in the medullary slice.Observe the roles of a7nAChR agonist acetylcholine (ACh) and its antagonist Alpha-bungarotoxin (α-BGT) on RRDA in the medullary slice of control group and experimental group rats, to clear whether a7nAChR take part in the inhibitory effects of prenatal alcohol exposure to medullary respiratory center of neonatal rat.2. Using Western Blot technology to research a7nAChR protein level in prenatal alcohol exposure neonatal rats slices.3. Using qRT-PCR technology to research a7nAChR mRNA level in prenatal alcohol exposure neonatal rat slices.Results1. Control group and experimental group slices discharge were stability without attenuation in60min, and the experiment model were stable and reliable. Experimental group slices discharge was weaker than control group(TI, IA, RC of experimental group were87.67±3.28%,90.57±4.81%,89.93±4.42%to the control), α7nAChR agonist ACh could excite slices discharge of the two groups, and control group excited effect was stronger than the experimental group(the change rates of experiment and control group were10.33±0.58%,9.69±0.48%,9.19±0.71%;18.33±0.60%,17.55±0.45%,19.56±0.63%, respectively). α7nAChR antagonist α-BGT had inhibitory effect on slices discharge of the two groups, while control group inhibitory effect was stronger than the experimental group(the change rates of experiment and control group were11.87±0.49%,14.64±0.69%,10.69±0.48%;14.64±0.65%,16.89±0.53%,15.56±0.64%, respectively).2. Western Blot results show that, prenatal alcohol exposure down regulated a7nAChR protein level in medullaly slices of neonatal rat(experimental group0.682±0.034, control1.012±0.090).3. qRT-PCR results show that, prenatal alcohol exposure down regulated a7nAChR mRNA level in medullaly slices of neonatal rat(experimental group0.716±0.047, control1.004±0.101). Conclusions1. Prenatal alcohol exposure depresses RRDA of the medullary slice, inhibits the respiratory function of medulla.2. Inhibit RRDA by down-regulating the α7nAChR protein and mRNA level perhaps is one of the mechanisms of prenatal alcohol exposure depresses respiratory function of medulla of neonatal rats.