0000000000374461
AUTHOR
Ivorra
Capacitative Ca2+ entry associated with α1-adrenoceptors in rat aorta
In rat aorta, depletion of internal Ca2+ stores by addition of noradrenaline (1 microM) induces a biphasic response (an initial phasic response and a tonic one) mediated by two different intracellular Ca2+ pools. This response cannot be repeated, suggesting a depletion of internal Ca2+ stores sensitive to noradrenaline. In absence of the agonist, this depletion is the signal for the entry of extracellular Ca2+, not only to refill the stores but also, under our experimental conditions, to activate the contractile proteins thus inducing an increase in the resting tone (IRT) that constitutes functional evidence of this Ca2+ entry. The ionic channels involved in the mechanism of the IRT have be…
Different β-adrenoceptor subtypes coupling to cAMP or NO/cGMP pathways: implications in the relaxant response of rat conductance and resistance vessels
Background and Purpose To analyse the relative contribution of β1-, β2- and β3-adrenoceptors (Adrb) to vasodilatation in conductance and resistance vessels, assessing the role of cAMP and/or NO/cGMP signalling pathways. Experimental Approach Rat mesenteric resistance artery (MRA) and aorta were used to analyse the Adrb expression by real-time-PCR and immunohistochemistry, and for the pharmacological characterization of Adrb-mediated activity by wire myography and tissue nucleotide accumulation. Key Results The mRNAs and protein for all Adrb were identified in endothelium and/or smooth muscle cells (SMCs) in both vessels. In MRA, Adrb1 signalled through cAMP, Adrb3 through both cAMP and cGMP…