[Effects of methylflavonolamine hydrochloride on contractility of isolated rabbit ileum].
Methylflavonolamine hydrochloride (MFA), verapamil (Ver), and trifluoperazine (Tri) inhibited the contractions induced by submaximal concentrations of acetylcholine (ACh) and serotonin (5-HT). IC50 values (mumol.L-1) were 33.2 +/- 0.7, 0.276 +/- 0.018, 3.83 +/- 0.23, and 15.31 +/- 0.10, 0.233 +/- 0.017, 2.33 +/- 0.20, respectively. MFA, Ver, and Tri inhibited the contractions induced by CaCl2 and pD'2 values were 4.3 +/- 0.3, 6.23 +/- 0.22, 4.99 +/- 0.24, respectively. MFA 3 mumol.L-1, Ver 0.03 mumol.L-1, and Tri 3 mumol.L-1 inhibited the contractions induced by ACh in Ca(2+)-free medium, while MFA 60 mumol.L-1, Tri 30 mumol.L-1, but not Ver 0.6 mumol.L-1, had pronounced inhibitions on extracellular calcium-dependent contractions induced by ACh. These results suggest that MFA has a calcium antagonistic effect and that MFA is similar to Tri, but not Ver, in mechanism.
Long
P
P
Department of Pharmacology, Shanxi Medical College, Taiyuan, China.
Yan
C H
CH
Zhang
M S
MS
Zhou
E F
EF
D000818:Animals; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D044948:Flavonols; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011817:Rabbits; D014268:Trifluoperazine / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D005419:Flavonoids; D044948:Flavonols; C052073:SIPI 549; D014268:Trifluoperazine; D014700:Verapamil