Genetically fixed enhanced G protein activation in essential hypertension.

Recent studies have shown that enhanced Na/H exchanger activity, a frequently observed abnormality in essential hypertension, persists in Epstein-Barr-virus-immortalised lymphoblasts from afflicted patients. This phenomenon is associated with an enhanced proliferation of these cell lines. Studies have ruled out structural changes in the Na/H exchanger protein, but demonstrated a distinct enhancement of intracellular signal transduction in these cell lines. The ultimate cause can be assigned to an obviously genetically fixed increased reactivity of pertussis-toxin-sensitive G proteins, which can easily explain the increased formation of intracellular- second messengers, enhanced Ca2+ signals, and enhanced proliferation of these cell lines. Thus, hypertension in the subset of patients with enhanced Na/H exchanger activity could be caused by increased G protein reactivity.