@entity1707 left descending coronary artery (main artery) and its next branch (branch arteries) differ in many properties. Here we report on the receptor types and the @entity141 pools utilized for endothelin (ET) contraction in 3 mm long de-endothelialized rings of the main (weight 7.38 +/- 0.38 mg) and the branch (1.07 +/- 0.03 mg) arteries. KCl (60 mM) contracted the main and the branch arteries with force of 41.8 +/- 3.1 and 16.9 +/- 1.0 mN (millinewton), respectively. Force of contraction for all the other agents was normalized taking the KCl value as 100%. We determined the total ET-induced responses using @entity18512 and those mediated by @entity30308 ) using @entity13071 . In @entity141 -containing solutions, @entity18512 contracted the main arteries with pEC50 = 8.2 +/- 0.1 and a maximum force of 98 +/- 5%. The branch arteries also gave similar values of pEC50 (8.4 +/- 0.1) and maximum force (99 +/- 14%). @entity13071 contracted the main and the branch arteries with pEC50 = 7.9 +/- 0.1 but the maximum force was significantly higher in the branch arteries (44 +/- 3%) than in the main (15 +/- 2%). In @entity141 -free solutions, the pEC50 values for @entity18512 or @entity13071 did not change but the maximum force of contraction was diminished considerably in both @entity732 . Thus, the left coronary artery and its next branch differ in that the role of @entity30308 ) receptors is greater in the latter.

XXXX )-mediated contraction differs between left descending coronary artery and its next branch.

@entity1707 :: ('9823', 'Species') :: ['Pig'] @entity30308 :: ('414911(Tax:9823)', 'Gene') :: ['ET(B'] @entity18512 :: ('396915(Tax:9823)', 'Gene') :: ['ET-1'] @entity141 :: ('CHEBI:29108', 'Chemical') :: ['Ca2+'] @entity732 :: ('MESH:D015356', 'Disease') :: ['main and branch arteries'] @entity13071 :: ('MESH:C074308', 'Chemical') :: ['IRL1620', 'IRL-1620']
@entity30308 :: (414911(Tax:9823),Gene) :: ['ET(B']
