title: L-type Ca(2+) channel current characteristics are preserved in rat tail artery myocytes after one-day storage.
abstract: OBJECTIVE
  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 Ca(2+) channels and contractile activity.
  
  
  METHODS
  Rings or vascular smooth muscle cells obtained from the rat tail main artery were used either freshly (R0h and VSMC0h) or stored for 24 h (R24h and VSMC24h) at 4 °C, to record whole-cell L-type Ca(2+) currents (IC a(L) ) or measure contractile responses.
  
  
  RESULTS
  R0h/VSMC0h and R24h/VSMC24h comparably contracted when stimulated with phenylephrine, high KCl or ATP. In both VSMC0h and VSMC24h, IC a(L) was identified and characterized as a stable inward current for at least 35 min; IC 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, IC a(L) intensity increased comparably; nifedipine shifted the steady-state inactivation curve towards more negative potentials, while verapamil blocked IC a(L) in a frequency-dependent manner and slowed down the rate of recovery from inactivation in a comparable way.
  
  
  CONCLUSIONS
  Findings show that smooth muscle contractile activity and the biophysical and pharmacological features of L-type Ca(2+) channels are similar in VSMC24h and VSMC0h. 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.
authors.affiliation: Dipartimento di Scienze della Vita, Università di Siena, Siena, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Mugnai
authors.forename: M
authors.initials: M
authors.lastname: Durante
authors.forename: G
authors.initials: G
authors.lastname: Sgaragli
authors.forename: S
authors.initials: S
authors.lastname: Saponara
authors.forename: G
authors.initials: G
authors.lastname: Paliuri
authors.forename: S
authors.initials: S
authors.lastname: Bova
authors.forename: F
authors.initials: F
authors.lastname: Fusi
mesh_terms: D000818:Animals; D001158:Arteries / Q000166:cytology / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D008297:Male; D032342:Muscle Cells / Q000378:metabolism*; D009119:Muscle Contraction / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D013623:Tail / Q000098:blood supply; D014021:Tissue Preservation / Q000379:methods*
chemical_list: D020746:Calcium Channels, L-Type
keywords: L-type Ca2+ channel current; cell storage; rat tail artery myocyte; whole-cell patch-clamp