| The hypertension is one of diseases to most harmful to man. However, the mechanism of hypertension is still unclear. It is common knowledge that the hypertension is shown as abnormal high blood pressure resulted from the increasing peripheral resistance of circulation.The function in the visceral resistance vessels makes a important contribution to the peripheral resistance and in a sense ,even controls the blood pressure of circulation. The calcium ion is the central one involved in smooth muscle cells actions and it goes into cell mainly through the voltage-dependent calcium channels(VDC). Consequently, VDCs control the function of smooth muscle cell and peripheral resistance of circulation, then regulate the blood pressure. In these years, there is just a few papers on the VDC conducted in viscera small artery (unresistance vessel) in SHRsp. They show some contradictory data about the role of VDC in hypertension. Although the patch-clamp technique has been successfully using in recording transmembrane ionic currents of miscellaneous cells from diversified tissues of various living beings, the technical complications of whole-cell Ca2+ currents in vascular smooth muscle cells(VSMC) of resistance mesenteric artery of SHRsp as well particularly remain primarily because of: 1)The developing enzyme-dissociation technique of viable muscle cells from the very small blood vessel wall. 2)The small size of the VSMC, a few Ca2+ channel numbers in cell membrane per cell and so the proportionately smaller magnitude of its inward calcium current (about is up to several folds less than in larger neuronal, cardiac and skeletal muscle cells). 3)Time-dependent rundown of Ca2+ current induced chiefly by whole-cell dialysis and the removal of possible cytosolic mediators of Ca2+ channel activity. Until recent, there is no any publication indicated whether the VDC might be abnormal in resistance VSMC of mesenteric artery of SHRsp. The purpose of the...
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