Alterations in the adenylate cyclase-cAMP-phosphodiesterase system in the locus coeruleus during the development of spontaneous hypertension of the rat

The quantitatively most important noradrenergic cell group of the brain is the locus coeruleus. Significantly increased cAMP concentration could be measured in spontaneously hypertensive rats in comparison to normotensive Wistar-Kyoto control rats at every stage investigated. Furthermore, both the basal activity and maximal stimulation of Ca++- and GTP-dependent adenylate cyclase as well as phosphodiesterase activity were significantly decreased in the spontaneously hypertensive rats at 14 weeks of age. The possible role of the locus coeruleus in spontaneous hypertension is presumed in counterregulatory mechanisms against rising blood pressure.