Functional Importance of L- and P/Q-Type Voltage-Gated Calcium Channels in Human Renal Vasculature
Open Access
- 1 September 2011
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Hypertension
- Vol. 58 (3), 464-470
- https://doi.org/10.1161/hypertensionaha.111.170845
Abstract
Calcium channel blockers are widely used for treatment of hypertension, because they decrease peripheral vascular resistance through inhibition of voltage-gated calcium channels. Animal studies of renal vasculature have shown expression of several types of calcium channels that are involved in kidney function. It was hypothesized that human renal vascular excitation-contraction coupling involves different subtypes of channels. In human renal artery and dissected intrarenal blood vessels from nephrectomies, PCR analysis showed expression of L-type (Ca v 1.2), P/Q-type (Ca v 2.1), and T-type subtype (Ca v 3.1 and Ca v 3.2) voltage-gated calcium channels (Ca v s), and quantitative PCR showed highest expression of L-type channels in renal arteries and variable expression between patients of subtypes of calcium channels in intrarenal vessels. Immunohistochemical labeling of kidney sections revealed signals for Ca v 2.1 and Ca v 3.1 associated with smooth muscle cells of preglomerular and postglomerular vessels. In human intrarenal arteries, depolarization with potassium induced a contraction inhibited by the L-type antagonist nifedipine, EC 50 1.2×10 −8 mol/L. The T-type antagonist mibefradil inhibited the potassium-induced constriction with large variations between patients. Interestingly, the P/Q-type antagonist, ω-agatoxin IVA, inhibited significantly the contraction with 24% at 10 −9 mol/L. In conclusion L-, P/Q, and T-type channels are expressed in human renal blood vessels, and L- and P/Q-type channels are of functional importance for the depolarization-induced vasoconstriction. The contribution of P/Q-type channels to contraction in the human vasculature is a novel mechanism for the regulation of renal blood flow and suggests that clinical treatment with calcium blockers might affect vascular reactivity also through P/Q-type channel inhibition.Keywords
This publication has 37 references indexed in Scilit:
- Voltage-gated divalent currents in descending vasa recta pericytesAmerican Journal of Physiology-Renal Physiology, 2010
- Effects of Benidipine, a Long-Acting T-Type Calcium Channel Blocker, on Home Blood Pressure and Renal Function in Patients with Essential HypertensionClinical Drug Investigation, 2009
- Heterogeneity of L- and T-Channels in the VasculatureHypertension, 2009
- The Role of L- and T-Type Calcium Channels in Local and Remote Calcium Responses in Rat Mesenteric Terminal ArteriolesJournal of Vascular Research, 2008
- Coexpression of Voltage-Dependent Calcium Channels Ca v 1.2, 2.1a, and 2.1b in Vascular MyocytesHypertension, 2006
- Low voltage-activated calcium channels in vascular smooth muscle: T-type channels and AVP-stimulated calcium spikingAmerican Journal of Physiology-Heart and Circulatory Physiology, 2005
- Renal Protection in Hypertensive Patients: Selection of Antihypertensive TherapyDrugs, 2005
- Depolarization‐induced calcium influx in rat mesenteric small arterioles is mediated exclusively via mibefradil‐sensitive calcium channelsBritish Journal of Pharmacology, 2004
- Major Outcomes in High-Risk Hypertensive Patients Randomized to Angiotensin-Converting Enzyme Inhibitor or Calcium Channel Blocker vs Diuretic: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)JAMA, 2002
- Autosomal dominant cerebellar ataxia (SCA6) associated with small polyglutamine expansions in the α1A-voltage-dependent calcium channelNature Genetics, 1997