Regional ischaemia

Figure 4.3 Effect of a variety of anti-free-radical interventions on reperfuslon-induced ventricular fibrillation In the Isolated perfused rat heart. Regional Ischaemia was induced by occluding a snare around the left anterior descending coronary artery and, after 10 min, hearts were reperfused by releasing the snare. Superoxide dismutase (SOD) (1 x 10° U/l), catalase (CAT) (1 X 10 U/l), mannitol (Mann) (50 mM), l-methlonlne (Methlon) (10 mM), glutathione (Glutath) (10 iiM) or desferrioxamlne (Deafer) (150 iim) were included throughout the experimental time course (n = 15/group). Redrawn with permission from Bernier et af. (1986).

Figure 4.4 Effect of a free-radical scavenger M-(2-mercaptoproplonyl)-glycine (MPG) on the recovery of contractile function following 15 min of regional ischaemia in the dog heart, (a) MPG infused 1 min before reperfusion, (b) MPG infused 1 min after reperfusion. Contractile function was assessed as changes in ventricular wall thickening measured using an ultrasonic pulsed-Doppler epicardial probe. Note The free radical scavenger MPG can reduce myocardial stunning only when present during the first minute of reperfusion. Redrawn with permission from Bolli et af. (1989).

Asano, T., Matsin, T., Basugi, N., Tamura, A., Takahura, K., Sano, K., 1984 The effect of indomethacin on cortical specific gravity during regional ischaemia and recirculation. In Recent Progress in the Study and Therapy of Brain Edema (Ko, K. G., Baethmann, A., eds.), pp. 617-626. New York Plenum Press. 

Gotoh, O., Koide, T., Asano, T., Takakura, K., 1983 The Na, K-ATPase activity and eicosanoids production profile of the brain micro vessel following permanent regional ischaemia in rats. J. Cereb. Blood Flow Metab. (Suppl. 1) 3, S289-S290. 

Younes, M., Mohr, A., Schoenberg, M.H. and Schildbeig, F.W. (1987). Inhibition of lipid peroxidation by superoxide dismutase following regional intestinal ischaemia and reperfiision. Res. Exp. Med. 187, 9-17. 

In two experimental models of ischaemia, it has been shown that HU-211 significantly increases cell survival. It was seen that after forebrain ischaemia produced by 20 min of carotid occlusion, the number of viable neurons in the hippocampal CA1 region of HU-211-treated rats was significantly higher than in controls. The same effect was seen in gerbils after 10 min of bilateral carotid occlusion on treatment with HU-211 [197, 198]. A related effect has been noted after rat optic nerve crush injury. Administration of HU-211 improved recovery of the nerve, with the visual evoked response amplitude increasing significantly [199],... 

Wise RJ S, Bernardi S, Frackowiak RS J et al. (1983). Serial observations on the pathophysiology of acute stroke. The transition from ischaemia to infarction as reflected in regional oxygen extraction. Brain 106 197-222... 

The negative T wave of subepicardial ischaemia is recorded in different leads, depending on the myocardial area affected by the occluded coronary artery (inferolateral or anteroseptal). In general, in case of single-vessel disease ischaemia is regional therefore, a mirror pattern may be observed in the FP (Figures 3.10 and 3.20). Much probably, ischaemia at rest is usually explained by only a culprit artery, even maybe stenosis in other arteries (multivessel disease). 

The electrocardiographic pattern of subendocardial injury in patients with ACSs is recorded in different leads, depending on the coronary artery involved and the location of the injured area. When the ischaemia is due to left main trunk (LMT) subocclusion or equivalent, or 3 proximal vessel diseases, the involvement of the left ventricle is circumferential. In case of single vessel disease or when in presence of multivessel disease, the active ischaemia is due to a culprit artery or two distal occlusions the involvement is considered regional (Sclarovsky 1989). The correlation between these... 

This ACS with regional involvement is usually secondary to an incomplete coronary artery occlusion in patients frequently presenting with prior predominantly regional subendocardial ischaemia and single- or multivessel disease, but one culprit artery. Any coronary artery may be the culprit one and the occlusion often is not proximal (Table 8.2). 

Transient arrest of cerebral circulation leads to neuronal cell death in selectively vulnerable regions of the brain. However, in ischaemia followed by recirculation... 

In conscious dogs, Vatner et al. (1977) measured regional blood flow in myocardial ischaemia with radio-labelled microspheres of 9 /an diameter before coronary occlusion, 10-15 min after occlusion, and 15-20 min after giving 0.5-2 mg pro-pranolol/kg. There was a gradient of blood flow ranging from 0.31 ml/g x min (severely ischaemic zone) through 0.83 ml/g x min (moderately ischaemic area) to 1.1 ml/g x min (in regions outside the area suppUed by the occluded vessel). 

Major changes in phosphorylation induced by ischaemia and subsequent reperfusion in rat striatum were observed for a 130-kDa protein, tentatively identified as the Ca "" transport ATPase, and calcium/calmodulin-dependent protein kinase II (Sankaran etal. 1997). A 200-300% increase in [ PjSNjATP photoinsertions was observed in the striatum and hippocampus region of a 43-kDa protein with an isoelectric point of 6.8. This protein was identified as glutamine synthetase and the increase in binding was found to be due to both increased copy number and activation by Mn ". An increase in [ PjSNjATP photoinsertions into a 55-kDa protein, identified as the P-subunit of tubulin, was found only in the striatum and hippocampus indicating the depolymerization of microtubulin in these tissues. 

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