We have examined the role of the anteroventral third ventricle (AV3V) region of the forebrain on the pressor responses to intravenous injections of the pituitary pressor agent, γ2-melanocyte-stimulating hormone (γ2-MSH) and the direct acting α1-adrenergic agonist, phenylephrine in unanesthetized rats. Lesions of the AV3V region produce a parallel shift to the right in the dose response curve to γ2-MSH, with no effect on the pressor response to phenylephrine. The lesion had no effect on the heart rate response to either agent. These experiments indicate that the forebrain region surrounding the anterior third ventricle area is important to some of the cardiovascular actions of γ2-MSH.
- Anteroventral third ventricle
- Blood pressure
- Heart rate
- Sympathetic nervous system
- γ-Melanocyte-stimulating hormone