| Abstract: | The role of angiotensin (ANG II) at the tissue level, particularly in the brain, remains imperfectly defined. We measured angiotensinogen (A°) mRNA in the brain stems, sensory and sympathetic ganglia, and blood vessels of Wistar-Kyoto (WKY) and stroke-prone spontaneously hypertensive rats (SHR-SP) by quantitative, liquid hybridization. We micro-injected ANG II and glutamate into the brain stems of these rats to gain insight into the functional significance of our findings. A° mRNA was found in the dorsolateral, dorsomedial, and ventrolateral pons, as well as in the dorsolateral, dorsomedial, and ventrolateral medulla of both strains. A° mRNA was 8–10 pg/μg total mRNA higher (p<0.05) in the dorsomedial medulla (nucleus tractus solitarii) in WKY and SHR-SP (28.27 ± 1.26 and 33.50 ± 1.42 pg/μg RNA respectively) than in the other areas. SHR-SP had higher values (27.22±1.77 vs. 21.53±0.57 pg/μg mRNA) than WKY (p<0.05) in the dorsolateral pons (locus coeruleus). A° mRNA was also identified in the optic nerves and chiasm, trigeminal and coeliac ganglia, arteries and veins. Injections of glutamate and ANG II into the dorsomedial, dorsolateral, and ventrolateral. |
