caa a22 4500 475743016 CHVBK 20180406123505.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1007/s002400050149 doi (NATIONALLICENCE)springer-10.1007/s002400050149 Regulation of renal artery smooth muscle tone by α1-adrenoceptors: role of voltage-gated calcium channels and intracellular calcium stores [Elektronische Daten] [R. E. Eckert, A. J. Karsten, J. Utz, M. Ziegler] The ischemia induced vasospasm of the renal arterial blood vessels mediated by α1-adrenoceptors is of importance for the loss of kidney function. This is based on reduced perfusion of the kidney cortex occuring in kidney transplant and organ preserving surgery. The present study considered the intracellular mechanism of the norepinephrine (NE) induced renal artery vasospasm by using swine renal artery smooth muscle ring. Norepinephrine and phenylephrine (PE) induced dose-dependent and fully reversible isometric contractions with a threshold concentration of 10 nM (n=7) and 10 nM (n=4), and an EC50 of 0.3 μM and 1 μM, respectively. The receptor was identified as α1A-subtype. The contraction was completely inhibited by verapamil (IC50=1.51 μM; n=11) and diltiazem (IC50=9.49 μM; n=8) and 85% by nifedipine (IC50=0.13 μM; n=21). Blockade of the intracellular inositol-1,4,5-trisphosphate (IP3)-sensitive Ca2+ store by thapsigargin (1 μM, n=7) or suppression of Ca2+ release from the intracellular Ca2+-sensitive Ca2+ store by ryanodine (100 μM, n=4) inhibited the PE induced contraction by 39.5% and 47.6%, respectively. The results suggest a key role of voltage-dependent Ca2+ channels and intracellular Ca2+ stores in the α1A-adrenoceptor induced contraction of the renal artery. Springer-Verlag Berlin Heidelberg, 2000 Key words Renal ischemia nationallicence Renal artery myocytes nationallicence Calcium channels nationallicence Calcium stores nationallicence Eckert R. E. Mühlstrasse 48, 66424 Homburg/Saar, Germany e-mail: PdDrEckert@aol.com Fax: +49 6841 67709, DE aut Karsten A. J. Department of Urology and Pediatric Urology, University of Saarland, Homburg/Saar, Germany, DE aut Utz J. Department of Urology and Pediatric Urology, University of Saarland, Homburg/Saar, Germany, DE aut Ziegler M. Department of Urology and Pediatric Urology, University of Saarland, Homburg/Saar, Germany, DE aut https://doi.org/10.1007/s002400050149 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002400050149 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Eckert R. E. Mühlstrasse 48, 66424 Homburg/Saar, Germany e-mail: PdDrEckert@aol.com Fax: +49 6841 67709, DE aut NATIONALLICENCE 700 1- Karsten A. J. Department of Urology and Pediatric Urology, University of Saarland, Homburg/Saar, Germany, DE aut NATIONALLICENCE 700 1- Utz J. Department of Urology and Pediatric Urology, University of Saarland, Homburg/Saar, Germany, DE aut NATIONALLICENCE 700 1- Ziegler M. Department of Urology and Pediatric Urology, University of Saarland, Homburg/Saar, Germany, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer