The influence of phentolamine on the fluorescence of catecholaminergic structures in selected areas of rat brain.
Wistar rats were given phentolamine into the ventriculus lateralis. The D1 group of rats received a larger dose than the D2 group. The animals were decapitated within 2 hours after phentolamine injection. The FALCK fluorescence technique was applied to demonstrate the fluorescence of catecholaminergic structures. The results in rat brain areas selected according to KONIG and KLIPPEL are shown in figs 10-46. Whereas earlier biochemical experiments did not show any phentolamine-induced changes in the NA level of the whole brain, the present histochemical experiments carried out with the fluorescence technique revealed the influence of phentolamine on individual structures and areas of the NA system. In comparison with the control material in 5 out of 11 areas the fluorescence was much weaker, in 3 it was similar to the control group, and in 3 (1 with a larger dose and 2 with a smaller dose of phentolamine) it was slightly stronger. The simultaneous increase of fluorescence in 6 out of 7 areas of the DA system may indicate a compensatory interaction of these areas as a response to the neuromediator decrease in the NA system. The paper discusses the increase in the intensity of fluorescence induced by a small dose of phentolamine in some brain areas, or by a large dose in others, both these alternatives depending on the neuromediator turnover.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D002395:Catecholamines / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D009928:Organ Specificity; D010646:Phentolamine / Q000494:pharmacology*; D051381:Rats
D002395:Catecholamines; D010646:Phentolamine