title: Effects of L-arginine on cerebral blood flow, microvascular permeability, number of perfused capillaries, and brain water content in the traumatized mouse brain.
abstract: It is has been suggested that decreased production of the vasodilatory and anti-aggregative substance NO (nitric oxide) may result in lower cerebral blood flow (CBF) in injured areas of the traumatized brain. The NO-precursor L-arginine has been shown to counteract CBF decreases early after trauma, but microcirculatory and more long-term effects on CBF of L-arginine have not been investigated. In an attempt to analyze effects of L-arginine on the microcirculation in the traumatized brain, the present study was designed to evaluate the effects of L-arginine compared to vehicle (0.9% saline) following a standardized controlled cortical-impact brain trauma in mice. Cerebral blood flow (autoradiography [(14)C]-iodoantipyrine), number of perfused capillaries (FITC-dextran fluorescence technique), brain water content (wet vs. dry weight) and the blood to brain transfer constant K(i) for [(51)Cr]-EDTA were analyzed in the injured and the contralateral cortex. Cortical blood flow in the injured cortex was 0.43+/-0.3 mL/g/min and 0.81+/-0.3 mL/g/min 3 h after trauma in the vehicle and L-arginine groups, respectively (p<0.05), and no treatment effect was seen 24 h after trauma. The number of perfused capillaries decreased following trauma and was unaffected by L-arginine. K(i) increased following trauma and was unaffected by L-arginine. Brain water content was lower in the L-arginine group than in the vehicle group 3 h after trauma and there was no difference between the groups 24 h after trauma. We conclude that L-arginine reduces brain edema formation and improves cortical blood flow in the early phase after a brain trauma, whereas no circulatory effects can be seen after prolonged treatment.
authors: Department of Anesthesia and Intensive Care, University of Lund and Lund University Hospital, SE-224 81 Lund, Sweden.
authors: C
authors: C
authors: Lundblad
authors: P
authors: P
authors: Bentzer
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001834:Body Water / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism*; D002196:Capillaries / Q000187:drug effects / Q000473:pathology; D002199:Capillary Permeability / Q000187:drug effects*; D002540:Cerebral Cortex / Q000098:blood supply*; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D002860:Chromium Radioisotopes; D004195:Disease Models, Animal; D004492:Edetic Acid; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D002860:Chromium Radioisotopes; D001120:Arginine; D004492:Edetic Acid