Localization and action of adenosine A2a receptors in regions of the brainstem important in cardiovascular control

摘要: Abstract In vitro autoradiography and central microinjections of a P1 adenosine A2a receptor antagonist have been employed to investigate possible role for centrally located receptors in modulation the baroreceptor reflex. using [125I]4-(2-[7-amino-2-[2-furyl][1,2,4]triazolol[2,3-a][1,3,5]triazin-5-yl-amino]ethyl)phenol ([125I]ZM241385), high-affinity antagonist, revealed heterogeneous distribution binding sites within lower brainstem rat. Image analysis showed high levels rostral regions both nucleus tractus solitarius ventrolateral medulla. Intermediate were observed commissural dorsal vagal motor nucleus, with low caudal medulla, hypoglossal nucleus. Unilateral unlabelled ZM241385 into had no effect on baseline arterial pressure, heart rate phrenic nerve activity recorded anaesthetized, artificially ventilated rats. However, reduced bradycardia evoked by stimulation ipsilateral aortic nerve. contrast, depressor response or reduction stimulation. Our results indicate that are number involved autonomic function, consistent idea acts as neuromodulator variety cardiorespiratory reflexes. Specifically, data support hypothesis activated during an important modulatory pattern cardiovascular changes associated this