caa a22 4500 477120040 CHVBK 20180405111634.0 cr unu---uuuuu 170330e19960401xx s 000 0 eng 10.1007/BF00227905 doi (NATIONALLICENCE)springer-10.1007/BF00227905 Alpha-adrenergic reactivity of the microcirculation in conscious spontaneously hypertensive rats [Elektronische Daten] [H. Struijker-Boudier, M. Messing, H. van Essen] The goal of this study was to determine the functional distribution of α1- and α2-adrenoceptors in the striated muscle microcirculation. Experiments were performed in intact conscious spontaneously hypertensive rats (SHR) that were provided with a dorsal microcirculatory chamber to allow microvascular diameter measurements. Administration of selective α1- and α2-agonists, phenylephrine and azepexole, respectively, induced different patterns of microvascular constriction. α1-Adrenoceptor stimulation showed a preferential constriction of large arteries and venules. The entire arteriolar microvasculature was sensitive to α2-adrenoceptor stimulation, whereas the venular vessels did not respond to azepexole. The selective α1- and α2-antagonists prazosin and yohimbine showed patterns of vasodilator activity comparable to those of the corresponding agonists. The specificity of the drug-induced effects was verified by comparing their effects with those of graded hemorrhage, a non-pharmacological method for blood pressure lowering. In the range of blood pressure decreases comparable to that obtained by α-adrenoceptor antagonists, graded hemorrhage did not influence microvascular diameters. These results show a differential functional distribution of α1- and α2-adrenoceptors along the microvascular tree in striated muscle of conscious SHR. Kluwer Academic Publishers, 1996 α-adrenoceptor agonists nationallicence α-adrenoceptor antagonists nationallicence hemorrhage nationallicence spontaneously hypertensive rats (SHR) nationallicence microcirculation nationallicence in vivo nationallicence Struijker-Boudier H. Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, Maastricht, The Netherlands aut Messing M. Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, Maastricht, The Netherlands aut van Essen H. Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, Maastricht, The Netherlands aut Molecular and Cellular Biochemistry Kluwer Academic Publishers 157/1-2(1996-04-01), 239-244 0300-8177 157:1-2<239 1996 157 11010 https://doi.org/10.1007/BF00227905 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00227905 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Struijker-Boudier H. Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- Messing M. Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, Maastricht, The Netherlands aut NATIONALLICENCE 700 1- van Essen H. Department of Pharmacology, Cardiovascular Research Institute Maastricht (CARIM), University of Limburg, Maastricht, The Netherlands aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers 157/1-2(1996-04-01), 239-244 0300-8177 157:1-2<239 1996 157 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer