[Insulin resistance and its relationship to intracellular calcium metabolism in essential hypertension].

Insulin resistance (IR) and intracellular calcium metabolism in 26 essential hypertensive (EH) patients (18 non-obese, 8 obese) were studied and compared with 24 normotensive (NT) subjects. The changes of plasma insulin and glucose before and after intravenous glucose tolerance test (IVGTT), the platelet cytoplasmic ionized calcium concentration ([Ca2+]i) with the fluorescent indicator Quin 2 and the Ca2+ pump activities in erythrocyte (RBC) lysates with the improved Vincenzi method were studied. These results strongly suggest that essential hypertension is characterized by fundamental metabolic abnormalities as well as hemodynamic abnormalities. Insulin resistance and abnormalities of cellular calcium metabolism, such as elevation in cytoplasmic [Ca2+], decrease in basal Ca-pump activity which rendered an increment of cytoplasmic [Ca2+], are major metabolic disturbances in patients with EH. The interaction between IR and cytoplasmic [Ca2+] is very complicated and needs further studies.