| RESEARCH PAPER
|Year : 1977 | Volume
| Issue : 4 | Page : 247-251
Effect of methyldopa treatment on vagal cardio-accelerator system
MF Lokhandwala, JP Buckley, BS Jandhyala
Mongrel dogs of either sex were treated orally with methyldopa (100 mg/kg) twice daily for three days. The frequency dependent tachycardia observed at the cessation of stimulation of the peripheral end of vagus was inhibited only at the lower frequency of stimulation in the methyldopa treated dogs, while there were no differences in the tachycardia observed at higher frequencies of stimulation between control and treated dogs. Atropine pm-treatment followed with desipramine enhanced the magnitude as well as duration of postvagal tachycardia in control and treated dogs. Propranolol administration almost completely abolished the postvagal tachycardia in both the groups of dogs. These results indicate that, as observed with other adrenergic neuron blocking agents. methyl-dopa treatment causes slight inhibition of postvagal tachycardia by impairing neuronal function of efferent sympathetic fibers present in the vagosympathetic trunk and does not alter the release of catecholamines from cardiac chromaffin cells.
M F Lokhandwala
Source of Support: None, Conflict of Interest: None