Central dopaminergic neurons during development of genetic and DOCA-salt hypertension in the rat.
The in vivo binding of [3H]spiroperidol was measured in discrete areas of the brain in 7-, 9- and 16-week-old spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto (WKY) controls. An increase in the [3H]spiroperidol binding in the striatum, tuberculum olfactorium and frontal cortex but not in the cerebellum was detected at all ages in SHR. The increase was more pronounced in 7- than in 9- or 16-week-old SHR. In vitro data indicated an increase in Bmax but no variation in Kd in the striatum of 7-week-old SHR. Moreover no difference was detectable in the dopaminergic cell bodies (A9, A10). This increase was specific to [3H]spiroperidol binding sites since no difference was observed in the in vivo binding of [3H]QNB and [3H]LSD in the same brain regions. No variation in dopamine level or dopamine utilization, as estimated by measuring the disappearance of the amine induced by alpha-methyl-p-tyrosine, was observed. The DOPA accumulation after injection of the DOPA decarboxylase inhibitor NSD 1015 was greater in the tuberculum olfactorium from 7-week-old SHR. An increase in [3H]spiroperidol binding sites was also observed in the striatum and tuberculum olfactorium after 7 weeks of DOCA-salt treatment. These results suggest that dopaminergic neurons might be implicated in the onset of hypertension in the rat.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002540:Cerebral Cortex / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D003900:Desoxycorticosterone / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism; D005838:Genotype; D008032:Limbic System / Q000378:metabolism; D008238:Lysergic Acid Diethylamide / Q000378:metabolism; D008297:Male; D008636:Mesencephalon / Q000378:metabolism; D009434:Neural Pathways / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D013134:Spiperone / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism
D011954:Receptors, Dopamine; D003900:Desoxycorticosterone; D013134:Spiperone; D011813:Quinuclidinyl Benzilate; D008238:Lysergic Acid Diethylamide; D004298:Dopamine