ABSTRACT
The distribution of nitroxide ergic neurons in the medulla oblongata nuclei in Wistar rats (n = 8) was studied histochemically (NADPH-diaphorase) and using immunohistochemistry with an antiserum against neuronal form of nitric oxide synthase (nNOS). NADPH-diaphorase activity was found in large and small neurons of the sensory, autonomic and motor nuclei. The latter were especially rich in the cells demonstrating the activity of the enzyme. Unlike NADPH-diaphorase, nNOS in the corresponding nuclei was always detected in the fewer number of neurons, predominantly of small sizes. The sensory nuclei (nucleus of solitary tract, reticular parvocellular and lateral nuclei, spinal nucleus of the trigeminal nerve) contained 1.5-3 times more nNOS neurons than in motor nuclei. In some nuclei (nucleus ambiguus, hypoglossal nerve nucleus), containing numerous NADPH-diaphorase-positive neurons, immunoreactive cells were particularly rare.
Subject(s)
Medulla Oblongata/enzymology , NADPH Dehydrogenase/metabolism , Neurons/enzymology , Nitric Oxide Synthase Type I/metabolism , Animals , Brain Stem/enzymology , Brain Stem/metabolism , Brain Stem/ultrastructure , Immunohistochemistry , Medulla Oblongata/metabolism , Medulla Oblongata/ultrastructure , Neurons/metabolism , Neurons/ultrastructure , Nitrogen Oxides/metabolism , Rats , Rats, Wistar , Tissue DistributionABSTRACT
The results of the application of a "pixel method" for the automated measurement of the intensity of histochemical reaction in the neurons are presented. The method is based on measuring principle, which includes the automatic counting the sum of brightnesses of all the pixels forming the image with the help of standard computer programs. The potential of this method is demonstrated on the example of NADPH-diaphorase activity study in the nitroxidergic neurons of sensory and motor nuclei of the medulla of healthy rats.
Subject(s)
Histocytochemistry/methods , Motor Neurons , NADPH Dehydrogenase/isolation & purification , Nitrergic Neurons , Animals , Image Processing, Computer-Assisted , Male , Models, Theoretical , Motor Neurons/cytology , Motor Neurons/enzymology , NADPH Dehydrogenase/metabolism , Nitrergic Neurons/cytology , Nitrergic Neurons/enzymology , RatsABSTRACT
Distribution of nitroxidergic neurons and neuronal NO-synthase activity in certain medulla oblongata nuclei were studied in normotensive and hypertensive rats with different types of arterial hypertension. In rats with renovascular hypertension, neuronal NO-synthase activity markedly decreased in most nuclei 2 weeks after surgery, while the number of NO-positive cells did not change significantly; after 4 weeks, the percentage of NO-positive neuron markedly decreased and neuronal NO-synthase activity also slightly decreased. No further decrease in neuronal NO-synthase activity was observed 8 week after intervention, but the percentage of NO-neurons decreased compared to that in normotensive rats. In spontaneously hypertensive rats, changes in most nuclei were directed similarly to those observed in 8-week renovascular hypertension, but motor nuclei demonstrated less differentiated reaction to hypertension. In all cases, changes in the parameters observed in sensory nucleus (n. solitarius) appeared earlier and were more pronounced than in nuclei of the reticular formation related to bulbar vasomotor center.