Sympathetically evoked Ca2+ signaling in arterial smooth muscle.
The sympathetic nervous system plays an essential role in the control of total peripheral vascular resistance and blood flow, by controlling the contraction of small arteries. Perivascular sympathetic nerves release ATP, norepinephrine (NE) and neuropeptide Y. This review summarizes our knowledge of the intracellular Ca2+ signals that are activated by ATP and NE, acting respectively on P2X1 and alpha1-adrenoceptors in arterial smooth muscle. Each neurotransmitter produces a unique type of post-synaptic Ca2+ signal and associated contraction. The neural release of ATP and NE is thought to vary markedly with the pattern of nerve activity, probably reflecting both pre- and post-synaptic mechanisms. Finally, we show that Ca2+ signaling during neurogenic contractions activated by trains of sympathetic nerve fiber action potentials are in fact significantly different from that elicited by simple bath application of exogenous neurotransmitters to isolated arteries (a common experimental technique), and end by identifying important questions remaining in our understanding of sympathetic neurotransmission and the physiological regulation of contraction of small arteries.
Zang
Wei-jin
WJ
Department of Pharmacology, Key Laboratory of Environment and Genes Related to Diseases of Ministry of Education, School of Medicine, Xi-an Jiaotong University, Xi-an 710061, China. zwj@mail.xjtu.edu.cn
Zacharia
Joseph
J
Lamont
Christine
C
Wier
Withrow Gil
WG
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D008638:Mesenteric Arteries / Q000294:innervation / Q000378:metabolism / Q000502:physiology; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000294:innervation / Q000378:metabolism / Q000502:physiology*; D009478:Neuropeptide Y / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058469:Receptors, Purinergic P2X; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000502:physiology*
D009478:Neuropeptide Y; D018340:Receptors, Adrenergic, alpha-1; D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X; D000255:Adenosine Triphosphate; D002118:Calcium; D009638:Norepinephrine