Brain dopamine D-2 receptor mRNA levels are elevated in young spontaneously hypertensive rats

Levels of brain dopamine D-2 receptor expression were compared between spon taneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) contr ols by quantitative in situ hybridisation, using a complementary RNA probe for D-2 receptor mRNA. In SHR which were 6 weeks of age, significantly high er levels of D-2 receptor mRNA were found in the caudate-putamen (42%), nuc leus accumbens (23%), olfactory tubercle (17%) and substantia nigra (38%) c ompared to age-matched WKY controls. D-2 receptor mRNA levels were also hig her in the substantia nigra (27%) of 12-14-week old SHR compared to WKY. Th e increased levels of dopamine D-2 receptor gene expression displayed in yo ung prehypertensive SHR could implicate altered central dopaminergic activi ty in the pathogenesis of hypertension. (C) 1999 Elsevier Science Ireland L td. All rights reserved.