NADH Fluorescence and Regional Energy Metabolites during Focal Ischemia and Reperfusion of Rat Brain

Abstract

Summary: Transient focal ischemia was produced in rat brain using simultaneous, reversible occlusion of the mid dle cerebral artery (MCA) and both carotid arteries. NADH tissue fluorescence and regional levels of ATP and lactate were measured after occlusion for 1 or 2.5 h and after reperfusion for 1 or 24 h following a 2.5-h insult. Occlusion for 1 or 2.5 h caused a marked but microhet erogenous increase in NADH fluorescence, which was restricted to the MCA territory of the ipsilateral cortex. In this ischemic core, tissue levels of ATP were nearly depleted, while lactate accumulated to 10-13 mmoUkg. Metabolic alterations were less pronounced in regions ad jacent to the ischemic core; however, one border region experienced a progressive increase in lactate between 1In recent years, several models of focal ischemia in rat brain have been developed employing middle cerebral artery (MCA) occlusion (Tamura et aI., 1981 ; Shigeno et aI., 1985;Chen et al., 1986; Brint et aI., 1988). Although regional blood flow and histo pathology have been well documented in these models, less is known about focal alterations of en ergy metabolites. Proximal occlusion of the MCA alone was reported to decrease ATP by 18% in pa rietal cortex and 46% in striatum by 2 h, with fur ther decreases occurring by 48 h (Nowicki et aI., 1988). In this study, however, regional information was limited by the large size (40 mg) of the areas analyzed. Micromethods have been used to demon strate near depletion of energy metabolites in the ischemic core following proximal MCA occlusion (Selman et aI., 1987). However, the anatomic vari ability of the ischemic core in this model required the use of a perfusion indicator in each animal.Received June 25, 1990; revised September 28, 1990; accepted October 2, 1990.Address correspondence and reprint requests to Dr. F. A. Welsh at 313 Medical Education Bldg., 36th and Hamilton Walk, Philadelphia, PA 19104-6070, U.S.A.Abbreviation used: MeA, middle cerebral artery. 459and 2.5 h. NADH fluorescence and metabolite levels were not significantly altered in subcortical structures. In animals reperfused after a 2.5-h insult, NADH fluores cence diminished in the ischemic core to abnormally low levels, ATP was restored only to 37-50% of control, and lactate remained elevated. By 24 h, histologic infarction was evident in the regions with metabolic impairment. These results indicate that focal depletion of energy me tabolites for 2.5 h caused irreversible impairment of en ergy metabolism and focal infarction even though lactate accumulation was moderate. Key Words: ATP-Focal ischemia-Lactate-Middle cerebral artery-NADH flu orescence-Regional metabolites.Reproducible infarction in the cerebral cortex has been reported in models of distal MCA occlusion combined either with bilateral carotid artery occlu sion (Chen et aI., 1986) or with ipsilateral carotid occlusion in spontaneously hypertensive rats (Brint et aI., 1988). Regional studies of metabolic alter ation in these models of distal MCA occlusion have not been...

NADH hyperoxidation correlates with enhanced susceptibility of aged rats to hypoxia

“…Recordings made in intact brains as well as in brain slices following either transient ischemic or hypoxic episodes revealed a decrease of NADH fluorescence and cytochrome a,a 3 reflectance significantly below control levels, which has been interpreted as hyperoxidation of intra-mitochondrial oxidative enzymes Duckrow et al, 1981;Feng et al, 1998;Paschen et al, 1985;Perez-Pinzon et al, 1998a, 1997a, 1998bPulsinelli et al, 1982;Rosenthal et al, 1995Rosenthal et al, , 1997Siesjo, 1981;Tanaka et al, 1986;Welsh et al, 1991;Welsh et al, 1982). The alternative explanation of a depletion of the electron carrier pool has been rejected by other authors .…”

“…Previous studies have shown hyperoxidation to be inversely related to adenosine 5′-triphosphate (ATP) recovery but directly correlated with histopathology (Welsh et al, 1991). Since the aged brain has shown increased vulnerability to hypoxic/ischemic damage Chih, 1995, Roberts andChih, 1998;Roberts et al, 1990), it is conceivable that injury to the aged brain will be exacerbated by the combined effects of changes in calcium buffering, prolonged hsd and resulting NADH hyperoxidation.…”

Anoxia-Induced Changes in Pyridine Nucleotide Redox State in Cortical Neurons and Astrocytes

“…Studies performed both in vivo and in vitro suggest that reperfusion after ischemia or reoxygenation after hypoxia leads to NAD(P)H hyperoxidation [8][9][10]. Studies describing NAD(P)H autofluorescence changes throughout ischemia/reperfusion in brain tissue or slices do not reveal the respective contribution of neurons and glial cells to the global emission.…”

Optical and pharmacological tools to investigate the role of mitochondria during oxidative stress and neurodegeneration

“…NADH fluorescence has also been measured in vivo under a number of altered physiological conditions including spreading depression and ischemia (Anderson et al, 1999;Tomlinson et al, 1993;Welsh et al, 1991). In more recent reports, NADH fluorescence was imaged from the cortex following middle cerebral artery occlusion using charge coupled device (CCD) cameras (Strong et al, 1996;Strong et al, 2000).…”