Vascular Smooth Muscle Cells Express the α
            <sub>1A</sub>
            Subunit of a P-/Q-Type Voltage-Dependent Ca
            <sup>2+</sup>
            Channel, and It Is Functionally Important in Renal Afferent Arterioles

Hansen, Pernille; Jensen, Boye L.; Andreasen, Ditte; Friis, Ulla Glenert; Skøtt, Ole

doi:10.1161/01.res.87.10.896

Cited by 76 publications

(89 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…HVA currents also inactivate over a wide range of potentials, with some R-type currents inactivating over the same voltage as T-type channels. These concerns take on additional weight with the finding that some vascular SMCs express non-L-type HVA currents (291) such as P-type currents (155). Native P-type currents can be mid-voltage activated (33).…”

Section: E Smooth Musclementioning

confidence: 99%

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

Perez‐Reyes

2003

Physiological Reviews

1,518

1,446

View full text Add to dashboard Cite

T-type Ca2+ channels were originally called low-voltage-activated (LVA) channels because they can be activated by small depolarizations of the plasma membrane. In many neurons Ca2+ influx through LVA channels triggers low-threshold spikes, which in turn triggers a burst of action potentials mediated by Na+ channels. Burst firing is thought to play an important role in the synchronized activity of the thalamus observed in absence epilepsy, but may also underlie a wider range of thalamocortical dysrhythmias. In addition to a pacemaker role, Ca2+ entry via T-type channels can directly regulate intracellular Ca2+ concentrations, which is an important second messenger for a variety of cellular processes. Molecular cloning revealed the existence of three T-type channel genes. The deduced amino acid sequence shows a similar four-repeat structure to that found in high-voltage-activated (HVA) Ca2+ channels, and Na+ channels, indicating that they are evolutionarily related. Hence, the α1-subunits of T-type channels are now designated Cav3. Although mRNAs for all three Cav3 subtypes are expressed in brain, they vary in terms of their peripheral expression, with Cav3.2 showing the widest expression. The electrophysiological activities of recombinant Cav3 channels are very similar to native T-type currents and can be differentiated from HVA channels by their activation at lower voltages, faster inactivation, slower deactivation, and smaller conductance of Ba2+. The Cav3 subtypes can be differentiated by their kinetics and sensitivity to block by Ni2+. The goal of this review is to provide a comprehensive description of T-type currents, their distribution, regulation, pharmacology, and cloning.

show abstract

Section: E Smooth Musclementioning

confidence: 99%

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

Perez‐Reyes

2003

Physiological Reviews

1,518

1,446

View full text Add to dashboard Cite

show abstract

“…Interestingly, P-(Ca V 2.1a) and Q-type Ca 2ϩ channel subunits (Ca V 2.1b) are splice variants of a single gene (ie, CACNA1A) and are expressed in the afferent arteriole. 17 Although splice variants have been demonstrated in neuronal and cardiac cells, 18 as well as in vascular smooth muscle cells from atherosclerotic tissues, 19 whether these variants affect the renal function remains undetermined.…”

Section: ؉ Channel Subtypesmentioning

confidence: 99%

Ca ²⁺ Channel Subtypes and Pharmacology in the Kidney

Hayashi

Wakino

Sugano

et al. 2007

Circulation Research

202

175

View full text Add to dashboard Cite

Abstract-A large body of evidence has accrued indicating that voltage-gated Ca 2ϩ channel subtypes, including L-, T-, N-, and P/Q-type, are present within renal vascular and tubular tissues, and the blockade of these Ca 2ϩ channels produces diverse actions on renal microcirculation. Because nifedipine acts exclusively on L-type Ca 2ϩ channels, the observation that nifedipine predominantly dilates afferent arterioles implicates intrarenal heterogeneity in the distribution of L-type Ca 2ϩ channels and suggests that it potentially causes glomerular hypertension. In contrast, recently developed Ca 2ϩ

show abstract

“…10 Primers for renin, ␣ 1C , and actin were as reported. 7,11 Amplification products were sequenced with ready-reaction mix from ABI using sense primer and read on an ABI Prism genetic analyzer.…”

Section: Reverse Transcription-polymerase Chain Reactionmentioning

confidence: 99%

Molecular and Functional Identification of Cyclic AMP-Sensitive BK _Ca Potassium Channels (ZERO Variant) and L-Type Voltage-Dependent Calcium Channels in Single Rat Juxtaglomerular Cells

Friis

Jørgensen

Andreasen

et al. 2003

Circulation Research

Self Cite

View full text Add to dashboard Cite

Abstract-This study aimed at identifying the type and functional significance of potassium channels and voltagedependent calcium channels (Ca v ) in single rat JG cells using whole-cell patch clamp. Single JG cells displayed outward rectification at positive membrane potentials and limited net currents between Ϫ60 and Ϫ10 mV. Blockade of K ϩ channels with TEA inhibited 83% of the current at ϩ105 mV. Inhibition of K V channels with 4-AP inhibited 21% of the current. Blockade of calcium-sensitive voltage-gated K ϩ channels (BK Ca ) with charybdotoxin or iberiotoxin inhibited 89% and 82% of the current, respectively. Double immunofluorescence confirmed the presence of BK Ca and renin in the same cell. cAMP increased the outward current by 1.6-fold, and this was inhibited by 74% with iberiotoxin. Expression of the cAMP-sensitive splice variant (ZERO) of BK Ca was confirmed in single-sampled JG cells by RT-PCR. The resting membrane potential of JG cells was Ϫ32 mV and activation of BK Ca with cAMP hyperpolarized cells on average 16 mV, and inhibition with TEA depolarized cells by 17 mV. The cells displayed typical high-voltage activated calcium currents sensitive to the L-type Ca v blocker calciseptine. RT-PCR analysis and double-immunofluorescence labeling showed coexpression of renin and L-type Ca v 1.2. The cAMP-mediated increase in exocytosis (measured as membrane capacitance) was inhibited by depolarization to ϩ10 mV, and this inhibitory effect was blocked with calciseptine, whereas K ϩ -blockers had no effect.

show abstract

Vascular Smooth Muscle Cells Express the α _1A Subunit of a P-/Q-Type Voltage-Dependent Ca ²⁺ Channel, and It Is Functionally Important in Renal Afferent Arterioles

Cited by 76 publications

References 32 publications

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

Ca ²⁺ Channel Subtypes and Pharmacology in the Kidney

Molecular and Functional Identification of Cyclic AMP-Sensitive BK _Ca Potassium Channels (ZERO Variant) and L-Type Voltage-Dependent Calcium Channels in Single Rat Juxtaglomerular Cells

Contact Info

Product

Resources

About

Vascular Smooth Muscle Cells Express the α 1A Subunit of a P-/Q-Type Voltage-Dependent Ca 2+ Channel, and It Is Functionally Important in Renal Afferent Arterioles

Cited by 76 publications

References 32 publications

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

Molecular Physiology of Low-Voltage-Activated T-type Calcium Channels

Ca 2+ Channel Subtypes and Pharmacology in the Kidney

Molecular and Functional Identification of Cyclic AMP-Sensitive BK Ca Potassium Channels (ZERO Variant) and L-Type Voltage-Dependent Calcium Channels in Single Rat Juxtaglomerular Cells

Contact Info

Product

Resources

About

Vascular Smooth Muscle Cells Express the α _1A Subunit of a P-/Q-Type Voltage-Dependent Ca ²⁺ Channel, and It Is Functionally Important in Renal Afferent Arterioles

Ca ²⁺ Channel Subtypes and Pharmacology in the Kidney

Molecular and Functional Identification of Cyclic AMP-Sensitive BK _Ca Potassium Channels (ZERO Variant) and L-Type Voltage-Dependent Calcium Channels in Single Rat Juxtaglomerular Cells