Ca2+influx insensitive to organic Ca2+entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aortaGouw, M. A. M., Wilffert, B., Wermelskirchen, D. & Van Zwieten, P. A., 22-Oct-1990, In : Pharmacology. 40, 5, p. 277-287 11 p.
Research output: Contribution to journal › Article › Academic › peer-review
We determined the contribution of intracellular Ca2+to the noradrenaline (NA, 3 x 10-5mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+release, we assumed that a Ca2+influx component contributes to the NA-induced contraction. This influx component proved resistant to the organic calcium entry blockers (CEBs) nifedipine, diltiazem, flunarizine and gallopamil which, in contrast, antagonized K+-induced Ca2+influx completely. Conversely, the NA-induced Ca2+influx component could be antagonized by the inorganic cations La3+, Cd2+, Mn2+, Ni2+and Co2+.45Ca2+uptake experiments also revealed that both KCl and NA induce Ca2+influx of which only the latter one is resistant to nifedipine. It was concluded that in the guinea pig aorta NA activates a receptor-operated channel through which Ca2+can be translocated from the extracellular space to the cytosol to contribute directly to contraction.
|Number of pages||11|
|Publication status||Published - 22-Oct-1990|
- 45Ca2+uptake, agonist-sensitive calcium pool, Ca2+entry blockade, Ca2+influx, guinea pig aorta, noradrenaline, aminophenol, cadmium, calcium 45, calcium antagonist, cobalt, diltiazem, egtazic acid, flunarizine, gallopamil, lanthanum, manganese, nickel, nifedipine, noradrenalin, radioisotope, animal cell, aorta, article, calcium transport, guinea pig, male, nonhuman, priority journal, smooth muscle contraction