Sharma P, Kaur G, Bhardwaj S K, Kaur G
Department of Biotechnology, Guru Nanak Dev University, Amritsar, India.
Brain Res Bull. 1998 Sep 1;47(1):81-6. doi: 10.1016/s0361-9230(98)00058-6.
We examined the effect of intracerebroventricular (i.c.v.) administration of mu-opioid agonist, morphine, and its antagonist naloxone followed by morphine on the activities of monoamine-metabolizing enzymes, namely tyrosine hydroxylase (TH) and monoamine oxidase (MAO) along with adenosinetriphosphatase (Na+, K+ -ATPase), the enzyme responsible for the maintenance of ionic gradients across the membrane, in seven discrete regions of brain from estrogen- and progesterone-primed ovariectomized rats. TH activity decreased after morphine treatment in some areas such as the median eminence-arcuate region (ME-ARC), the amygdala, and the thalamus, showing statistically significant change. MAO activity increased in all the areas studied, but more appreciable change was observed in medial preoptic area (mPOA), the ME-ARC region, and the cortex. Pronounced increase in Na+, K+ -ATPase enzyme activity was observed after the drug treatment. Naloxone given prior to morphine injection resulted in recovery of the enzyme activities in most of the areas studied. Our study may provide insights into the precise opioidergic modulation of gonadotropin releasing hormone (GnRH) release mechanisms through the involvement of monoaminergic system, elucidating the basis of various neuronal dysfunctions and their management in opioid addicts.
我们研究了向经雌激素和孕酮预处理的去卵巢大鼠脑室内注射μ-阿片类激动剂吗啡及其拮抗剂纳洛酮后再注射吗啡，对单胺代谢酶（即酪氨酸羟化酶（TH）和单胺氧化酶（MAO））以及腺苷三磷酸酶（Na +，K + -ATP酶）活性的影响，Na +，K + -ATP酶是负责维持跨膜离子梯度的酶，实验涉及大脑七个离散区域。在某些区域，如正中隆起-弓状核区域（ME-ARC）、杏仁核和丘脑，吗啡处理后TH活性降低，呈现出统计学上的显著变化。在所有研究区域中MAO活性均升高，但在内侧视前区（mPOA）、ME-ARC区域和皮质中观察到更明显的变化。药物处理后观察到Na +，K + -ATP酶活性显著增加。在注射吗啡前给予纳洛酮可使大多数研究区域的酶活性恢复。我们的研究可能通过单胺能系统的参与，为促性腺激素释放激素（GnRH）释放机制的精确阿片能调节提供见解，阐明阿片类药物成瘾者各种神经功能障碍的基础及其处理方法。
