Blood pressure increased dramatically in hypertensive rats after left hemisphere lesions with 6-hydroxydopamine

• Published in: Neuroscience letters Vol. 500; no. 2; pp. 148 - 150
• Main Authors: Banegas, I., Prieto, I., Segarra, A.B., Durán, R., Vives, F., Alba, F., Luna, J.D., de Gasparo, M., Wangesteen, R., Ruiz-Bailén, M., Ramírez-Sánchez, M.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 15-08-2011; Elsevier
• Subjects: Animals; Asymmetry; Autonomic nervous system; Biological and medical sciences; Blood Pressure - drug effects; Blood Pressure - physiology; Brain damage; Corpus Striatum - drug effects; Corpus Striatum - pathology; Functional Laterality; Fundamental and applied biological sciences. Psychology; Heart Rate - drug effects; Heart Rate - physiology; Hypertension; Hypertension - pathology; Hypertension - physiopathology; Male; Oxidopamine - toxicity; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Species Specificity; Substantia Nigra - drug effects; Substantia Nigra - pathology; Vertebrates: nervous system and sense organs; Hypertension; Brain damage; Asymmetry; Autonomic nervous system; Rat; Rodentia; Central nervous system; Oxidopamine; Encephalon; Vertebrata; Mammalia; Left hemisphere; Animal; Blood pressure; Hemodynamics; Lesion
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2011.06.025

► There exists an asymmetrical organization of the nervous system in blood pressure control. ► The asymmetrical cardiovascular response to unilateral brain lesions, suggests that left injury may have a worst prognosis. ► Increased levels of blood pressure after left hemisphere damage may be linked to increased peripheral resistance by sympathetic activation.
Plasma angiotensinase activity, nitric oxide and systolic blood pressure (SBP) were differently affected after unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA), depending on the brain hemisphere injured. Moreover, normotensive and hypertensive rats responded differently suggesting an asymmetry in the organization of the autonomic nervous system of the vessels. The aim of this study was to investigate the evolution of SBP and heart rate (HR) over time after nigrostriatal lesions in normotensive and hypertensive rat strains. Unilateral depletions of brain dopamine were performed by injecting 6-OHDA into the left or right striatum of normotensive and hypertensive rats. Vehicle without 6-OHDA was unilaterally injected in control (sham) groups. SBP and heart rate (HR) were measured in un-anesthetised animals 10 and 3 days before administration of 6-OHDA or vehicle and 3 and 25 days after treatment. In normotensive rats, at the end of study, SBP increased significantly from pre-lesioned values in left-lesioned animals but no differences were observed in right-lesioned or sham groups. Before sacrifice, there was a significant reduction from pre-lesion values in HR. In hypertensive animals, there was a highly significant increase of SBP in left-lesioned and sham left rats and a slight increase in right-lesioned but no differences were observed in sham right group. No differences in HR were observed throughout the study in the groups studied. The present results represent direct experimental evidence of an asymmetrical cardiovascular response to unilateral brain lesions, suggesting that left injury may have a worst prognosis.