Key result
Noradrenaline microinjected into rat dPAG evokes a pressor response and bradycardia via acute vasopressin release.
Why the study?
The cardiovascular effects of noradrenaline microinjected into the dorsal periaqueductal gray area and the peripheral mechanisms mediating these effects were not fully characterized in unanaesthetized rats.
Does noradrenaline microinjected into the dorsal periaqueductal gray area evoke cardiovascular responses in unanaesthetized rats?
Does noradrenaline microinjected into the dorsal periaqueductal gray area evoke cardiovascular responses in unanaesthetized rats?
Answers are grounded in this paper and cite their sources.
Activation of noradrenergic receptors within the dorsal periaqueductal gray area evokes pressor responses mediated by acute vasopressin release in unanaesthetized rats.
The periaqueductal grey area (PAG) is a mesencephalic region that is involved in the modulation of cardiovascular changes associated with behavioural responses. Among the neurotransmitters present in the PAG, noradrenaline (NA) is also known to be involved in central nervous system cardiovascular regulation. In the present study we report the cardiovascular effects of the microinjection of NA into the dorsal portion of the PAG (dPAG) of unanaesthetized rats and the peripheral mechanism involved in their mediation. Injection of NA in the dPAG of unanaesthetized rats evoked a dose-dependent pressor response accompanied by bradycardia. The magnitude of the pressor responses was higher at more rostral sites in the dPAG and decreased when NA was injected into the caudal portion of the dPAG. The responses to NA were markedly reduced in urethane-anaesthetized rats. The pressor response was potentiated by i.v. pretreatment with the ganglion blocker pentolinium and blocked by i.v. pretreatment with the vasopressin antagonist dTyr(CH2)5(Me)AVP. The results suggest that activation of noradrenergic receptors within the dPAG can evoke pressor responses, which are mediated by acute vasopressin release.
No takes yet. Share an insight, caveat, or question.
Pelosi et al. (2005) studied this question. Noradrenaline microinjection into the dorsal periaqueductal gray area was evaluated on Pressor response and bradycardia. Microinjection of noradrenaline into the dorsal periaqueductal gray area of unanaesthetized rats evoked a dose-dependent pressor response accompanied by bradycardia, mediated by acute vasopressin release.
Synapse has enriched 10 related papers. Consider them for comparative context: