Sweet Chestnut (Castanea sativa Mill.) Bark Extract: Cardiovascular Activity and Myocyte Protection against Oxidative Damage

Table 4

Antagonist affinities at guinea pig right atria, expressed as p𝐴₂ values.

Compound	Right atrium p𝐴2^a
	Inotropy	Chronotropy
Atropine	9.45 ± 0.04	9.21 ± 0.03
Atropine + extract	9.41 ± 0.03	9.19 ± 0.02

^aThe agonist was carbachol. Each p𝐴₂ value was obtained for three different concentrations and was calculated from Schild plots [25, 28]. Results are presented as mean ± S.E.M.