The roles of cell Ca2+, protein kinase C and the Na(+)-H+ antiport in the development of hypertension and insulin resistance.

There is evidence that the cytosolic free Ca2+, protein kinase C, and the Na(+)-H+ antiport cross-communicate with one another through positive and negative feedback mechanisms, thereby maintaining cellular Ca2+ and pH homeostasis. This triumvirate may play a role in the development of insulin resistance--a common characteristic of both essential hypertension and non-insulin-dependent diabetes mellitus. Circulating cells from patients with essential hypertension and non-insulin-dependent diabetes mellitus demonstrate elevated cytosolic free Ca2+, increased protein kinase C activity, or both, and these perturbations are associated with augmented activity of the Na(+)-H+ antiport. If present in other cells (e.g., striated muscle cells and adipocytes), these alterations could underlie insulin resistance in essential hypertension and non-insulin-dependent diabetes mellitus.