Hydrolysable tannins depress cardiac papillary muscle contraction and propranolol-induced negative inotropism.
We studied effects of hydrolysable tannins on rat papillary muscle contractions induced by propranolol. The developed force of papillary muscle was measured isometrically with an inductive force transducer. The IC(50) values for digallic acid, gallic acid, germin D, praecoxin A and 1-desgalloyl rugosin F were 4.2 x 10(-5) M, 1.3 x 10(-4) M, 1,4 x 10(-4) M, 1.5 x 10(-4) and 1.7 x 10(-4) M, respectively. Incubation with tannins significantly attenuated the propranolol-induced negative inotropic contractile response. These results show that hydrolysable tannins depress muscle contractions and potentiate the activities of β-adrenergic blocker.
Lee
Hobeom
H
Division of Pathophysiology, College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea.
Lee
Ji Yun
JY
Suh
Moo Hyun
MH
Sim
Sang-Soo
SS
Lee
Min-Won
MW
Kim
Chang Jong
CJ
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D029401:Betulaceae / Q000737:chemistry*; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D007537:Isometric Contraction / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D010936:Plant Extracts / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000319:Adrenergic beta-Antagonists; D047348:Hydrolyzable Tannins; D010936:Plant Extracts; D011433:Propranolol