刺激迷走神经向中端对大鼠不同脑区脑啡肽含量的影响

自从1975年(Hughes et al. 1975)发现脑啡肽以来,经多方面研究已认为脑啡肽可能是一种神经递质,它具有多种生理功能(范少光、汤健,1978)。据新近文献报道,脑啡肽与催产素及加压素三者具有共同存在的并存关系(Martin and Voigt。1981)。 已经证明,刺激迷走神经向中端,可引起脑内释放乙酰胆硷,从而促使神经垂体释放压加素和催产素,肾上腺释放肾上腺素(Chang, et al. 1937;1961,1964;吕运明等1965,1977;唐正荣1981)。但是,刺激迷走神经向中端,是否也能引起脑内脑啡肽的释放,迷走神经传入纤维与脑内脑啡肽能神经原之间,是否存有机能上的联系?关于这个

THE EFFECTS OF STIMULATION OF CENTRAL END OF VAGUS ON CONTENTS OF ENKEPHALINS IN SEVERAL BRAIN AREAS OF RATS

By means of radioimmunoassay we studied the effects of stimulation of central end of vagus on contents of enkephalins in several brain areas (hypothalamus, corpus striatum, thalamus, brain stem and pituitary). Fourteen male rats were used and divided into experimental and control groups. Each group had seven animals, the animals were anesthetized with urethane and the vagus on both sides of the neck were severed. The results are as follows:1. In hypothalamus and thalamus: The contents of leu-enkephalin were decreased by 65% (P<0.05) and 73% (P<0.01) respectively, while those of the met-enkephalin was unchanged.2. In corpus striatum: The contents of met-enkephalin were significantly reduced. The reduction was 82% (P<0.05) less than that of the controls. However, there were no significant changes in leu-enkephalin contents at this area.3. In brain stem: The contents of leu-enkephalin showed no changes, while those of met-enkephalin were significantly elevated, 8,8 times (P<0.05) more than those of the controls.4. In pituitary: The contents of met-enkephalin showed no obvious changes, but the contents of leu-enkephalin were greatly increased, 23 times (P<0.001) more than those of the controls.In summary, the stimulation of central end of vagus could induce influences in the contents of leu- or met-enkephalin in different brain areas. The results showed that there is functional relation ship between the fiber of vagus and neuron of the enkephalin. But the peptide concentrations in different brain areas are different from each other. The mechanism of there differences in response to stimulation remains to be investigated. Besides, according our results support the view that the pituitary contains enkephalin.