Differential effects on phrenic output of two dopamine agonists, apomorphine and bromocriptine

摘要: Abstract Effects of dopamine agonists upon phrenic output were studied in decerebrate, vagotomized, paralyzed, carotid-body denervated dogs. Intravenous administration was without effect these Apomorphine (APO) increased minute activity while bromocriptine (BRO) decreased following intravenous injection at doses 100 μg/kg for each drug. BRO-induced decreases associated with amplitude; burst frequency remained unchanged. Conversely, APO-induced increases resulted from significant both and amplitude. Both APO BRO significantly prolonged inspiratory duration shortened expiratory duration. Responses to abolished haloperidol. These results confirm previous evidence the existence dopaminergic receptors within central nervous system, which are inaccessible exogenous dopamine, can alter timing as well amplitude characteristics integrated neurogram. excitation inhibition mediated by mechanisms or below caudal brainstem.