Boldine shows a concentration-dependent relaxation effect on the rat ileum preparation
with a pD2 of 3.77 ± 0.12. The alkaloid also produces a concentration-dependent parallel shift
of the curve-response to acetylcholine, therefore it directly interferes with the
cholinergic mechanism associated with the contraction, behaving as a competitive antagonist
with a pA2 of 4.78 ± 0.19. On the other hand, boldine produces a non-parallel shift of the contraction
response induced by barium, revealing the occurrence of a non-competitive antagonism.
This effect could be the result of interference with intracellular events associated
with the barium-induced changes in calcium pools.
Boldine -
Peumus boldus
- (S)-2,9-dihydroxy-1,10-dimethoxyaporphine - muscle-relaxing effect - contractility of
rat ileum
