Calcium channel blockers are widely used for treatment of hypertension, and L-type voltage-gated calcium channels are regarded as the subtype involved in the excitation-contraction mechanism in resistance vessels. However, both L- and P/Q-type calcium channels are of functional importance for the depolarization-induced contraction in human renal blood vessels. It was hypothesized that non-L-type channels are of general importance for vascular function in human blood vessels. In human internal mammary arteries from bypass surgery patients, PCR analysis showed expression of L-type (Cav 1.2) and T-type (Cav 3.1 and Cav 3.2) voltage-gated calcium channels and variable expression of P/Q-type (Cav 2.1) channels between patients. Immunohistochemical labeling of human mammary arteries vessels revealed signal for Cav 2.1 in both endothelium and smooth muscle cells. The T-type blocker mibefradil (10-7 M) significantly attenuated the depolarization-induced contraction (60 mM potassium) by 21±6,7% in human mammary arteries using a myograph set-up. The P/Q type antagonist, ω-agatoxin IVA (10-9 M and 10-8 M) inhibited the potassium-induced contraction with large variations between patients. In human intrarenal arteries, mibefradil had a tendency to inhibit the contraction induced by 60 mM potassium. In summary, human mammary arteries express functionally significant L-type and T-type channels with variable presence and significance of P/Q-type channels. We conclude that non-L-type channels are involved in excitation-contraction coupling in human arteries and could be involved in regulation of blood pressure.