Abstract
The mechanisms regulating spiral modiolar artery (SMA) tone are not known, yet their characterization is pivotal for understanding inner ear blood flow regulation. Sphingosine-1-phosphate (S1P), known to stimulate vasoconstriction in several vascular beds, is a candidate regulator of SMA tone with potential pathophysiological relevance. Gerbil SMAs were isolated, cannulated and pressurized (30 mm Hg transmural) for experimentation under near-in vivo conditions. For functional experiments, vascular diameter and intracellular Ca2+ were simultaneously measured. Standard RT-PCR and immunohistochemical techniques were also employed. mRNA transcripts encoding sphingosine kinase, S1P phosphohydrolase and three S1P receptors (S1P(1-3)) were detected in the SMA. S1P induced dose-dependent vasoconstriction of the SMA (EC50 = 115 nmol/L), and enhanced the apparent Ca2+-sensitivity of the contractile apparatus. Noradrenaline did not elicit vasoconstriction. The Rho kinase inhibitor Y27632 (1 micromol/L) reversed S1P-induced vasoconstriction and the S1P-mediated enhancement of Ca2+-sensitivity. RhoA was observed to translocate to the plasma membrane in response to stimulation with 30 micromol/L S1P. We conclude that all key signalling pathw...Continue Reading
Citations
Jul 7, 2010·Lab on a Chip·Axel GüntherSteffen-Sebastian Bolz
Oct 12, 2010·Stroke; a Journal of Cerebral Circulation·Elias Q SchererSteffen-Sebastian Bolz
Nov 3, 2011·PloS One·Xu LiLi Qiao
Apr 26, 2012·PloS One·Mihwa LimYoung-Ho Lee
Mar 30, 2007·Acta Paediatrica. Supplement·Martin C MichelStephan L M Peters
Jun 22, 2013·International Journal of Audiology·Warangkana ArpornchayanonSebastian Strieth
Apr 16, 2016·Scientific Reports·Deron R HerrJerold Chun
Oct 31, 2014·PLoS Genetics·Jing ChenKaren P Steel
Jun 19, 2016·The Journal of Pharmacology and Experimental Therapeutics·Anna Cantalupo, Annarita Di Lorenzo
Nov 5, 2016·Annual Review of Physiology·Keisuke Yanagida, Timothy Hla
Apr 6, 2007·Biology of Reproduction·Nicola K HudsonMichael J Taggart
Aug 19, 2007·Journal of Lipid Research·Kelley M Argraves, W Scott Argraves
Jun 4, 2011·Otolaryngology--head and Neck Surgery : Official Journal of American Academy of Otolaryngology-Head and Neck Surgery·Warangkana ArpornchayanonSebastian Strieth
Sep 30, 2006·Circulation Research·Ravichandran RamasamyAnn Marie Schmidt
Jun 7, 2012·Circulation·Jingli YangSteffen-Sebastian Bolz
Feb 8, 2007·The Journal of Biological Chemistry·Mari KonoRichard L Proia
Jul 8, 2016·Scientific Reports·Neil J InghamKaren P Steel
Jun 14, 2016·Otology & Neurotology : Official Publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology·Kariem SharafMartin Canis
Aug 21, 2013·The Annals of Otology, Rhinology, and Laryngology·Friedrich IhlerMartin Canis
Nov 30, 2019·International Journal of Otolaryngology·Michael Eisenhut