ISSN:
1420-908X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Five different antihistamines (astemizole, clemastine, dimethindene, pheniramine and terfenadine) were tested for their antagonistic actions on histamine-induced contractions in isolated strips of the aorta and the trachea of the guinea pig. All antagonists led to a shift of the concentration-response curves for histamine and a decrease in the maximal response. pA2-values were calculated from the competitive part of the antagonism, whereas pD′2-values were calculated for the non-competitive part of the antagonism. Marked differences were observed for the various compounds: clemastine and dimethindene with pA2-values for the aorta (trachea) of 9.31 (8.64) and 9.12 (8.39), respectively, showed the highest affinity, whereas pheniramine with a pA2-value for the aorta (trachea) of 7.42 (7.10) showed the lowest affinity. The compounds astemizole and terfenadine took an intermediate position. Similar results were obtained for the non-competitive part of the antagonism with a marked antagonistic effect produced by dimethindene and clemastine (pD′2 values for the aorta: 7.99 and 6.50; trachea: 7.71 and 7.10, respectively) and less suppression of the maximal response for astemizole, terfenadine and pheniramine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01997387
