High-Dose, but Not Low-Dose, Aspirin Impairs Anticontractile Effect of Ticagrelor following ADP Stimulation in Rat Tail Artery Smooth Muscle Cells

Table 2

Maximal relative response for phenylephrine in relation to the presence of 2-MeS-ADP, ticagrelor and the dose of aspirin in arteries without vascular endothelium.

	𝑛^1	𝐸max [%]^2	𝑃^3
Control rats: PHE (10 μM/L)	20	132.0±14.6
Ticagrelor pretreated rats: PHE (10 μM/L) + ticagrelor (1 μM/L) + 2-MeS-ADP (10 μM/L)	20	97.0±15.9	𝑃<0.0001^a
Low-dose aspirin pretreated rats: PHE (10 μM/L)	21	115.0±12.2	ns^a
Ticagrelor and low-dose aspirin pretreated rats: PHE (10 μM/L) + ticagrelor (1 μM/L) + 2-MeS-ADP (10 μM/L)	21	90.0±13.7	𝑃<0.0001^a; 𝑃<0.0001^b; ns^c
High-dose aspirin pretreated rats: PHE (10 μM/L)	21	125.0±12.1	ns^a
Ticagrelor and high-dose aspirin pretreated rats: PHE (10 μM/L) + ticagrelor (1 μM/L) + 2-MeS-ADP (10 μM/L)	21	123.0±14.2	ns^a; 𝑃<0.0001^c; ns^d

PHE: phenylephrine; 2-MeS-ADP: stable analogue of adenosine diphosphate; ¹number of concentration-response curves used for calculations; ²𝐸_max: calculated as a percent of maximal response for PHE; ^a𝑃 value calculated versus controls; ^b𝑃 value calculated versus PHE + low-dose aspirin; ^c𝑃 value calculated versus PHE + ticagrelor + 2-MeS-ADP; ^d𝑃-value calculated versus PHE + high-dose aspirin.