Effects of chronic dietary lithium on phosphatidylinositol pathway in heart and arteries of DOCA-salt hypertensive rats.

The sensitivity of the phosphatidylinositol (PI) pathway was evaluated in slices of atria (A), ventricles (V), and mesenteric artery (MA) in normotensive (NT) and DOCA-salt hypertensive (DOCA-HT) rats. During norepinephrine (NE) activation, the PI reactivity was two to three times greater in A, V, and MA of HT rats compared to NT rats. The long-term (2 weeks) administration of dietary lithium (Li) reduced the activation of PI by NE in left A and right V but caused no changes in MA of HT rats. The Li-treated hypertensive rats were also characterized by a lower systolic blood pressure and a lower ratio of ventricular weight/body weight. Plasma epinephrine (E) levels that were higher in HT rats were normalized in DOCA-HT + Li-treated rats, while the NE levels remained elevated in the DOCA-HT + Li group.