title: Abnormal coronary function in mice deficient in alpha1H T-type Ca2+ channels.
abstract: Calcium ion (Ca2+) influx through voltage-gated Ca2+ channels is important for the regulation of vascular tone. Activation of L-type Ca2+ channels initiates muscle contraction; however, the role of T-type Ca2+ channels (T-channels) is not clear. We show that mice deficient in the alpha1H T-type Ca2+ channel (alpha(1)3.2-null) have constitutively constricted coronary arterioles and focal myocardial fibrosis. Coronary arteries isolated from alpha(1)3.2-null arteries showed normal contractile responses, but reduced relaxation in response to acetylcholine and nitroprusside. Furthermore, acute blockade of T-channels with Ni2+ prevented relaxation of wild-type coronary arteries. Thus, Ca2+ influx through alpha1H T-type Ca2+ channels is essential for normal relaxation of coronary arteries.
authors: Howard Hughes Medical Institute, University of Iowa, Iowa City, IA 52242, USA.
authors: Chien-Chang
authors: CC
authors: Chen
authors: Kathryn G
authors: KG
authors: Lamping
authors: Daniel W
authors: DW
authors: Nuno
authors: Rita
authors: R
authors: Barresi
authors: Sally J
authors: SJ
authors: Prouty
authors: Julie L
authors: JL
authors: Lavoie
authors: Leanne L
authors: LL
authors: Cribbs
authors: Sarah K
authors: SK
authors: England
authors: Curt D
authors: CD
authors: Sigmund
authors: Robert M
authors: RM
authors: Weiss
authors: Roger A
authors: RA
authors: Williamson
authors: Joseph A
authors: JA
authors: Hill
authors: Kevin P
authors: KP
authors: Campbell
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology*; D002118:Calcium / Q000378:metabolism*; D020747:Calcium Channels, T-Type / Q000235:genetics / Q000502:physiology*; D003331:Coronary Vessels / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D004452:Echocardiography; D004562:Electrocardiography; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005260:Female; D005355:Fibrosis; D005727:Ganglia, Spinal / Q000166:cytology; D018390:Gene Targeting; D006321:Heart / Q000502:physiology; D006339:Heart Rate; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D009206:Myocardium / Q000473:pathology; D009474:Neurons / Q000378:metabolism; D009532:Nickel / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D020747:Calcium Channels, T-Type; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D009532:Nickel; D000109:Acetylcholine; D002118:Calcium