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L‐type C a 2+ channel current characteristics are preserved in rat tail artery myocytes after one‐day storage
Author(s) -
Mugnai P.,
Durante M.,
Sgaragli G.,
Saponara S.,
Paliuri G.,
Bova S.,
Fusi F.
Publication year - 2014
Publication title -
acta physiologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.591
H-Index - 116
eISSN - 1748-1716
pISSN - 1748-1708
DOI - 10.1111/apha.12282
Subject(s) - vascular smooth muscle , verapamil , nifedipine , myocyte , phenylephrine , medicine , chemistry , agonist , endocrinology , biophysics , biology , calcium , receptor , smooth muscle , blood pressure
Abstract Aim To develop a cheap and simple method of storing for 24‐h vascular tissue and single myocytes while preserving therein the biophysical and pharmacological characteristics of L ‐type C a 2+ channels and contractile activity. Methods Rings or vascular smooth muscle cells obtained from the rat tail main artery were used either freshly ( R 0h and VSMC 0h) or stored for 24 h (R24h and VSMC 24h) at 4 °C, to record whole‐cell L‐type Ca 2+ currents ( I C a(L) ) or measure contractile responses. Results R 0h/ VSMC 0h and R24h/ VSMC 24h comparably contracted when stimulated with phenylephrine, high KC l or ATP . In both VSMC 0h and VSMC 24h, I C a(L) was identified and characterized as a stable inward current for at least 35 min; I C a(L) was comparably inhibited by the Ca 2+ antagonists nifedipine, verapamil and diltiazem and increased by the Ca 2+ channel agonist (S)‐(‐)‐Bay K 8644; current density and current–voltage relationships were similar; at more hyperpolarized holding potentials, I C a(L) intensity increased comparably; nifedipine shifted the steady‐state inactivation curve towards more negative potentials, while verapamil blocked I C a(L) in a frequency‐dependent manner and slowed down the rate of recovery from inactivation in a comparable way. Conclusion Findings show that smooth muscle contractile activity and the biophysical and pharmacological features of L‐type Ca 2+ channels are similar in VSMC 24h and VSMC 0h. The fact that reproducible results were obtained in vascular myocytes up to 24 h after dissociation may facilitate vascular smooth muscle cell investigation by increasing throughput and reducing the number of animals required.