Biphasic manner of melittin on isolated guinea pig atria
Abstract
"AIM:
To investigate the effect of melittin (Mel) on isolated guinea pig atria.
METHODS:
The effect of Mel on the contraction and heart rate of isolated guinea pig atria at different concentrations was determined.
RESULTS:
Mel at a lower concentration (0.1-0.8 mumol.L-1) enhanced the contraction of left atria in a concentration-dependent manner; but at a higher concentration (1.6-12.8 mumol.L-1) it exerted an inhibitory effect. At 0.1-30 mumol.L-1 it was found to increase heart rate of right atria. In addition, verapamil (Ver) 0.3 mumol.L-1 was found to depress the effect of Mel.
CONCLUSION:
Mel possesses a biphasic effect on left atria and a positive chronotropic effect on right atria. Its mechanism might be related with Ca2+ channel."
Keywords:
To investigate the effect of melittin (Mel) on isolated guinea pig atria.
METHODS:
The effect of Mel on the contraction and heart rate of isolated guinea pig atria at different concentrations was determined.
RESULTS:
Mel at a lower concentration (0.1-0.8 mumol.L-1) enhanced the contraction of left atria in a concentration-dependent manner; but at a higher concentration (1.6-12.8 mumol.L-1) it exerted an inhibitory effect. At 0.1-30 mumol.L-1 it was found to increase heart rate of right atria. In addition, verapamil (Ver) 0.3 mumol.L-1 was found to depress the effect of Mel.
CONCLUSION:
Mel possesses a biphasic effect on left atria and a positive chronotropic effect on right atria. Its mechanism might be related with Ca2+ channel."