Measurement of Ca2+ pump-mediated efflux in hypertension.

Ca2+ homeostasis has been a prominent research area in the study of hypertension. There is convincing evidence that hypertension in spontaneously hypertensive rats is characterized by enhanced Ca2+ influx in various cell types. It is, however, still unclear whether hypertension is associated with reduced or enhanced Ca2+ efflux. Reduced Ca2+ efflux would augment the effects of enhanced Ca2+ influx. However, enhanced Ca2+ extrusion may occur as an adaptive process to minimize the effects of Ca2+ overload. This question remains unanswered because of inconsistent results obtained using a variety of experimental techniques. In this article we have reviewed the research findings and discuss existing and possible new techniques to assess Ca2+ efflux in hypertension, with particular attention to vascular smooth muscle. We have focused mainly on studies using the spontaneously hypertensive rat and discuss its appropriateness as a model for essential hypertension.