L-PDMP improves glucosylceramide synthesis and behavior in rats with focal ischemia

Abstract

Background: It has been shown that exogenic administration of glycosphingolipids (GSLs) induces outgrowth of neurites from cultured nerve cells. Furthermore, the activator of glucosylceramide synthase, L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (L-PDMP), is thought to exhibit stimulatory effects on both the biosynthesis and neurotrophic actions of GSL in the same culture system. To investigate the effect of GSLs on focal cerebral ischemia in vivo, L-PDMP was injected into the intraperitoneal space of rats during the chronic phase following permanent occlusion of the left middle cerebral artery (MCA) and thereafter, the levels of GSLs and their effects on behavioral changes were examined

Methods: The levels of cerebrosides, sphingomyelin (SM) and ceramide in the ischemic cortex were measured by gas–liquid chromatography (GLC) after separation by high-performance thin-layer chromatography, using the internal standards N-heptadecanoyl-D-cerebroside, N-heptadecanoyl-D-sphingomyelin and N-heptadecanoyl-D-sphingosine, respectively. To determine the sugar components of the cerebrosides, the trimethylsilylated derivatives of their methylglycosides after methanolysis were analysed directly by GLC.

Results: The L-PDMP treatment induced a 2.4-fold increase in glucosylceramide, the precursor of gangliosides, but no changes were evident in the levels of SM and ceramide in the ischemic cerebral cortex. The ischemic rats treated with L-PDMP showed improved re-acquisition of memory and learning in the Morris water maze task.

Conclusion: These results suggest that the pharmacological effects of L-PDMP include significant facilitation of glucosylceramide biosynthesis and improvement of neural function.     

Therapeutic time window in the penumbra during permanent focal ischemia in rats: changes of free fatty acids and glycerophospholipids

To better define a therapeutic time window for reducing the extent of damage in ischemic penumbra, the time courses of changes in the glycerophospholipid and free fatty acid (FFA) levels were determined in the rat cerebral cortex following induction of the permanent focal ischemia. Focal ischemia induced a biphasic increase in FFA levels in the cerebral cortex, which had been recognized as the ischemic penumbra during the early stages after permanent occlusion of the middle cerebral artery (MCA). The first increase in FFA levels, in which the polyunsaturated fatty acid (PUFA) contained a large number of arachidonic acid (C20:4) molecules, began at 30 min and reached a peak at 1 h, followed by transient return to each sham level 2-6 h after the onset of MCA occlusion. Thereafter, the delayed increase in FFA levels, showing more increases of docosahexaenoic acid (C22:6) molecules than the C20:4 in PUFA compositions, occurred at 24 h. In contrast, the levels of phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-bisphosphate (PIP2) decreased rapidly at 30 min of ischemia and returned transiently to each sham level at 1-6 h. The levels of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), including polyphosphoinositides (PIPs), began to decrease significantly during the late stages, i.e., 24 h after induction of ischemia. These results suggest that the time-dependent changes in FFA and PIPs levels during the early stages of ischemia (until 6 h after induction) might be an important determinant of the subsequent neuronal death in the ischemic penumbra and that the breakdown of glycerophospholipids in the later stages after the induction of focal ischemia was associated with the development of infarction in the cerebral cortex.     

大鼠局灶性脑缺血再灌注后FADD mRNA及其蛋白的表达变化

目的观察大鼠脑缺血再灌注后缺血半暗带皮质内Fas死亡结构域相关蛋白（FADD）mRNA及蛋白的表达变化。方法用半定量的逆转录PCR（RT-PCR）法检测缺血2h再灌注不同时间点缺血半暗带皮质内FADD mRNA的表达,Western blot检测FADD蛋白表达的变化。结果缺血半暗带脑皮质内FADD mRNA及其蛋白的表达于缺血灌注后3h明显升高,再灌注后12h达高峰（P＜0．01）,至再灌注后24h明显下降。结论脑缺血再灌注后缺血半暗带皮质内FADD mRNA及蛋白表达均明显增加,提示FADD可能在脑缺血再灌注损伤中发挥重要作用。     

Fatty acid composition of myelin isolated from the brain of a patient with cellular deficiency of co-enzyme forms of vitamin B12

Myelin fractionation and subsequent lipid isolation have been carried out on a brain from a patient who suffered from a cellular deficiency of the adenosylcobalamin and methylcobalamin co-enzyme forms of vitamin B₁₂. Examination of the fatty acid composition of choline and ethanolamine glycerophospholipids indicated a relative enrichment of odd-chain fatty acids which were identified by gas-liquid chromatography-mass spectroscopy as C₁₅, C_15:1, C₁₇ and C_17:1. A mixture of methyl branched C₁₇ fatty acids was also identified. Odd-chain fatty acids accounted for 9.8% of the total fatty acid in the myelin choline phospholipid compared to control values of 1.2%. The affected brain myelin phospholipids had a lower unsaturated fatty acid content. Examination of the myelin sphingolipids, sphingomyelin, cerebroside and sulfatide, yielded abnormal fatty acid profiles. The sphingomyelin contained only small amounts of C_24:1 fatty acid. Both normal and hydroxy fatty acid containing cerebroside and sulfatide had reduced levels of C₂₄ fatty acid. Determination of the relative hydroxy and normal fatty acid content of the galactolipids indicated an abnormally high hydroxy fatty acid level. Abnormal fatty acid profiles of brain cerebral sphingolipids have not been previously described in cases of vitamin B₁₂ deficiency. Whether or not these alteration are characteristic will only be established by estimating sphingolipids in other such cases.     

Pivotal role for acidic sphingomyelinase in cerebral ischemia-induced ceramide and cytokine production, and neuronal apoptosis

Stroke is a major cause of long-term disability, the severity of which is directly related to the numbers of neurons that succumb to the ischemic insult. The signaling cascades activated by cerebral ischemia that may either promote or protect against neuronal death are not well-understood. One injury-responsive signaling pathway that has recently been characterized in studies of non-neural cells involves cleavage of membrane sphingomyelin by acidic and/or neutral sphingomyelinase (ASMase) resulting in generation of the second messenger ceramide. We now report that transient focal cerebral ischemia induces large increases in ASMase activity, ceramide levels, and production of inflammatory cytokines in wild-type mice, but not in mice lacking ASMase. The extent of brain tissue damage is decreased and behavioral outcome improved in mice lacking ASMase. Neurons lacking ASMase exhibit decreased vulnerability to excitotoxicity and hypoxia, which is associated with decreased levels of intracellular calcium and oxyradicals. Treatment of mice with a drug that inhibits ASMase activity and ceramide production reduces ischemic neuronal injury and improves behavioral outcome, suggesting that drugs that inhibit this signaling pathway may prove beneficial in stroke patients.     

Protein kinase C as an early and sensitive marker of ischemia-induced progressive neuronal damage in gerbil hippocampus

In the model of transient brain ischemia of 6-min duration in gerbils we have estimated:

1. The concentration of brain gangliosides: A significant decrease to about 70% of control was observed selectively in the hippocampus at 3 and 7 d after ischemia.
2. The activity of Na⁺,K⁺-ATPase: The enzyme activity was not affected in either hippocampus nor in cerebral cortex.
3. The malonylaldehyde (MDA) concentration: The levels of MDA had increased at 30 min after ischemia up to 123 and 129% of control in hippocampus and cerebral cortex, respectively.
4. Immunoreactivity of protein kinase C detected by Western blotting: In hippocampus the early translocation toward membranes was followed by a decrease in total enzyme content at 6, 24, 72, and 96 h of postischemic recovery. Also, a sharp increase of 50 kDa isoform (PKM) was noticed immediately and at the early recovery times.

The behavior of these biochemical markers of ischemic brain injury in the hippocampus after the short (6 min) insult was contrasted with their reaction in the cerebral cortex as well as after prolongation of the ischemia to 15 min. These results taken together indicate that an early increase in PKC translocation followed by a decrease is the most symptomatic for selective, delayed, postischemic hippocampal injury, resulting from short duration (6 min) ischemia of the gerbil brain.     

大鼠急性脑缺血后Hephaestin的表达变化

目的 研究大鼠急性局灶性脑缺血后皮质和纹状体Hephaestin表达的变化。方法 线栓法制备大鼠急性大脑中动脉阻塞(MCAO)再灌注模型,在再灌注后的不同时间点应用免疫组化、图像分析以及SDS-PAGE Werstern blot方法检测缺血侧皮质和纹状体的表达变化。结果 MCAO再灌注后大鼠出现大脑中动脉梗死的神经系统损害体征,TTC染色有白色梗死区。Hephaestin在正常大鼠的皮质、纹状体有表达,在急性脑缺血再灌注后12h缺血侧皮质、纹状体表达明显增加并持续到再灌注后48h,在24h时到达高峰(P<0.01),至1周时表达较正常明显减少(P<0.01)。结论 大鼠急性脑缺血再灌注后Hephaestin的表达出现明显的变化,在急性脑缺血的病理生理变化中可能起着重要的作用。     

Altered ceramide acyl chain length and ceramide synthase gene expression in Parkinson's disease

Genetic studies have provided increasing evidence that ceramide homeostasis plays a role in neurodegenerative diseases including Parkinson's disease (PD). It is known that the relative amounts of different ceramide molecular species, as defined by their fatty acyl chain length, regulate ceramide function in lipid membranes and in signaling pathways. In the present study we used a comprehensive sphingolipidomic case‐control approach to determine the effects of PD on ceramide composition in postmortem brain tissue from the anterior cingulate cortex (a region with significant PD pathology) and the occipital cortex (spared in PD), also assessing mRNA expression of the major ceramide synthase genes that regulate ceramide acyl chain composition in the same tissue using quantitative PCR. In PD anterior cingulate cortex but not occipital cortex, total ceramide and sphingomyelin levels were reduced from control levels by 53% (P < 0.001) and 42% (P < 0.001), respectively. Of the 13 ceramide and 15 sphingomyelin molecular lipid species identified and quantified, there was a significant shift in the ceramide acyl chain composition toward shorter acyl chain length in the PD anterior cingulate cortex. This PD‐associated change in ceramide acyl chain composition was accompanied by an upregulation of ceramide synthase‐1 gene expression, which we consider may represent a response to reduced ceramide levels. These data suggest a significant shift in ceramide function in lipid membranes and signaling pathways occurs in regions with PD pathology. Identifying the regulatory mechanisms precipitating this change may provide novel targets for future therapeutics. © 2013 International Parkinson and Movement Disorder Society     

2-CAdo对脑缺血再灌注后血清及皮质TNF-α含量的影响

目的:研究大鼠局灶性脑缺血再灌注后非选择性腺苷受体激动剂2-CAdo(2-Chloroadenosine)对血清及皮质肿瘤坏死因子-α(TNF-α)含量的影响,从而进一步探讨腺苷受体激动剂的神经保护作用。方法 采用线栓法制备大鼠局灶性脑缺血再灌注模型,于缺血后即刻经静脉注射2-CAdo,应用放射免疫法测定缺血1h再灌注6h后血清及皮质TNF-α的含量。结果 2-CAdo能显著降低脑缺血再灌注后血清及皮质TNF-α的含量。结论 2-CAdo可通过降低脑缺血再灌注后增高的TNF-α水平,达到神经保护作用。     

Astrocytic function assessed from 1-14C-acetate metabolism after temporary focal cerebral ischemia in rats.

Astrocytes play many roles essential for normal brain activity. The ability of these cells to recover after temporary focal cerebral ischemia is likely to be one important determinant of the extent of brain dysfunction and tissue damage. We have assessed astrocytic function based on the incorporation of radiolabel from 1-14C-acetate into glutamine at 1 hour of recirculation after middle cerebral artery occlusion for 2 or 3 hours in rats. There were marked differences in the response between subregions within the tissue subjected to ischemia, but the overall pattern of changes was similar after each ischemic period. The striatum, which forms part of the severely ischemic focal tissue during arterial occlusion, showed a large (44% to 68%) decrease in glutamine labeling compared with equivalent tissue from the contralateral hemisphere. In contrast, 14C-glutamine content was not significantly altered in perifocal tissue in the cerebral cortex, which was subjected to more moderate ischemia. Cortical focal tissue also was not significantly affected, but the response was much more variable between rats. In these brain subregions, the extent of recovery of the 14C-acetate metabolism after ischemia was not a good predictor of the likelihood of subsequent infarct development. Interestingly, a similar pattern of responses persisted when recirculation was extended to 4 hours. These results indicate that many astrocytes, particularly in the cortex, remain viable and capable of at least some complex oxidative metabolism during the first few hours of recirculation.     

Changes in regional cerebral catecholamines following middle cerebral artery occlusion in the rat

Ischemic brain injury affects the content and metabolism of brain monomines. Our aim was to know the time course of changes in regional cerebral catecholamines during focal cerebral ischemia, and whether focal cerebral ischemia may affect the metabolism of catecholamines in distant area of the brain. Methods Fifty-five rats were subjected to occlusion of the middle cerebral artery (MCA) on the olfactory tract, under halothane anesthesia. Fourteen animals were sham-operated group. Animals were decapitated at 1/2, 1,2,3,6,12 and 24 hours post-occlusion (PO), respectively. The brains were removed, and the brain structures dissected out include bilateral corpus striatum, cerebral cortex (MCA territory) and cerebellar hemisphere. Catecholamines were extracted by alumina procedure, and determined by high-performance liquid chromatography with electrochemical detection. Results Dopamine (DA) contents, in ipsilateral corpus striatum and cerebral cortex to the ischemia, decreased at 1 hour PO, and reached, at 6 hours PO, to 40% of control value in corpus striatum and 30% in cerebral cortex, respectively. After 6 hours PO, DA remained low. Norepinephrine (NE) content in the ipsilateral corpus striatum gradually reduced and reached to 60% of control value at 24 hours PO. NE in the ipsilateral cerebral cortex decreased to 50% of control at 1 hour PO, and thereafter remained reduced. In the contralateral corpus striatum and cerebral cortex, either DA or NE showed no significant changes, except 1/2 hour PO. NE contents in bilateral cerebral cortex showed a transient increase at 1/2 hour PO. Cerebellar NE content, bilaterally, reduced slowly to 70% of control at 24 hours PO.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evidence of phosphorylation of Akt and neuronal survival after transient focal cerebral ischemia in mice.

The serine-threonine kinase, Akt, prevents apoptosis by phosphorylation at serine-473 in several cell systems. After phosphorylation, activated Akt inactivates other apoptogenic factors, such as Bad or caspase-9, thereby inhibiting cell death. The present study examined phosphorylation of Akt at serine-473 and DNA fragmentation after transient focal cerebral ischemia in mice subjected to 60 minutes of focal cerebral ischemia by intraluminal blockade of the middle cerebral artery. Phospho-Akt was analyzed by immunohistochemistry and Western blot analysis. The DNA fragmentation was evaluated by terminal deoxynucleotidyl transferase-mediated uridine 5-triphosphate-biotin nick end-labeling (TUNEL). Immunohistochemistry showed the expression of phospho-Akt was markedly increased in the middle cerebral artery territory cortex at 4 hours of reperfusion compared with the control, whereas it was decreased by 24 hours. Western blot analysis showed a significant increase of phospho-Akt 4 hours after focal cerebral ischemia in the cortex, whereas phospho-Akt was decreased in the ischemic core. Double staining with phospho-Akt and TUNEL showed different cellular distributions of phospho-Akt and TUNEL-positive staining. Phosphorylation of Akt was prevented after focal cerebral ischemia by LY294002, a phosphatidylinositol 3-kinase inhibitor, which facilitated subsequent DNA fragmentation. These results suggest that phosphorylation of Akt may be involved in determining cell survival or cell death after transient focal cerebral ischemia.     

Increased susceptibility to ischemic brain injury in cyclooxygenase-1-deficient mice.

Cyclooxygenase-1 (COX-1), a rate-limiting enzyme in the synthesis of prostanoids, is involved in selected vasodilatatory responses of the cerebral circulation. Cyclooxygenase-1-null mice were used to determine whether COX-1 influences cerebral ischemic damage. The middle cerebral artery was occluded in COX-1 -/- and +/+ mice (n = 9/group), and lesion volume was determined in thionin-stained sections 24 or 96 hours later. Middle cerebral artery occlusion produced larger infarcts in COX-1 -/- mice, both at 24 (35 +/- 17%; P < 0.05) and 96 hours (41 +/- 16%; P < 0.05) after ischemia. The enlargement was not due to increased susceptibility to glutamate excitotoxicity, because microinjection of N-methyl-D-aspartate or kainate in the parietal cortex produced comparable lesions in COX-1 +/+ and -/- mice ( P > 0.05; n = 8/group). To examine the contribution of hemodynamic factors to the enlargement of the infarct, cerebral blood flow was monitored by laser-Doppler flowmetry in the ischemic territory (n = 6/group). Although the reduction in cerebral blood flow was comparable in the ischemic core ( P > 0.05), at the periphery of the ischemic territory the reduction was greater in COX-1 -/- mice (-58 +/- 4%) than in COX-1 +/+ mice (-34 +/- 5%; P < 0.05). It is concluded that mice lacking COX-1 are more susceptible to focal cerebral ischemia, an effect that can be attributed to a more severe cerebral blood flow reduction in vulnerable regions at the periphery of the ischemic territory. Thus, the vascular effects of COX-1 may contribute to maintain cerebral blood flow in the postischemic brain and, as such, play a protective role in ischemic brain injury.     

Neuroprotective effects of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), an antioxidant in middle cerebral artery occlusion induced focal cerebral ischemia in rats

Abstract

Objectives: In the present study, we have investigated the neuroprotective potential of 6hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), in middle cerebral artery occlusion (MCAO) induced focal cerebral ischemia.

Methods: Sprague–Dawley rats were subjected to 2 hours of MCAO followed by 22 or 70 hours of reperfusion. After reperfusion, rats were evaluated for neurological deficits and cerebral infarction. Brain malondialdehyde (MDA) level and in situ terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) were also estimated.

Results: Focal cerebral ischemia produced a significant infarct volume and neurological scores as compared with sham-operated animals. Cerebral ischemia reperfusion injury was associated with an increase in lipid peroxidation in ipsilateral and contralateral hemisphere of brain along with an increase in TUNEL positive cells in ipsilateral hemisphere of brain sections indicating oxidative stress and DNA fragmentation, respectively. Trolox (10 and 30 mg/kg, i.p.) treatment significantly decreased neurological damage which was evident from the reduction in infarct volume and neurological score. Trolox (30 mg/kg) also attenuated oxidative stress and DNA fragmentation.

Discussion: Oxidative stress-induced neuronal damage is implicated in the pathophysiology of cerebral ischemia. Our study suggests that Trolox is a potent neuroprotective agent in focal cerebral ischemia and its neuroprotective effects may be attributed to the reduction of lipid peroxidation and DNA fragmentation.     

Anti-inlfammatory properties of lipoxin A4 protect against diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury

Lipoxin A4 can alleviate cerebral ischemia/reperfusion injury by reducing the inlfammatory reaction, but it is currently unclear whether it has a protective effect on diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury. In this study, we established rat models of diabetes mellitus using an intraperitoneal injection of streptozotocin. We then induced focal cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours. After administration of lipoxin A4via the lateral ventricle, infarction volume was reduced, the expression levels of pro-inlfammatory factors tumor necrosis factor alpha and nuclear fac-tor-kappa B in the cerebral cortex were decreased, and neurological functioning was improved. These ifndings suggest that lipoxin A4 has strong neuroprotective effects in diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury and that the underlying mech-anism is related to the anti-inlfammatory action of lipoxin A4.     

Strong attenuation of ischemic and postischemic brain edema in rats by a novel free radical scavenger

Regional changes in the amount of free fatty acids, polyphosphoinositides, and water content in the cerebral cortex were examined using a middle cerebral artery occlusion model of rats. The amount of various free fatty acids increased as polyphosphoinositides decreased during 3 and 6 hours of ischemia in the occluded middle cerebral artery territory. After 3 hours of reperfusion following 3 hours of ischemia, free fatty acids partially recovered while polyphosphoinositides did not. Water content increased significantly after 3 and 6 hours of ischemia, and a further increase was found after 3 hours of reperfusion following 3 hours of ischemia. The change of polyenoic fatty acids in this occluded middle cerebral artery territory was much smaller than that in the case of decapitation ischemia, although the amounts of polyphosphoinositides and monoenoic and saturated fatty acids showed almost identical changes in both cases, probably because polyenoic fatty acids may be washed out and/or peroxidatively consumed in the middle cerebral artery occlusion model due to its residual blood flow. Changes in the area surrounding the occluded middle cerebral artery territory were similar to the above results, although less dramatic. However, there was no change in free fatty acids, polyphosphoinositides, and water content in the contralateral cortex. A novel free radical scavenger (MCI-186), which prevents both nonenzymatic peroxidation and lipoxygenase activity in vitro, markedly attenuated the ischemic and postischemic brain swelling. These results suggest that free radical mechanisms may be involved in ischemic and postischemic brain edema.     

Anti-inflammatory properties of lipoxin A4 protect against diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury

Lipoxin A4 can alleviate cerebral ischemia/reperfusion injury by reducing the inflammatory reaction,but it is currently unclear whether it has a protective effect on diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury.In this study,we established rat models of diabetes mellitus using an intraperitoneal injection of streptozotocin.We then induced focal cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours.After administration of lipoxin A4 via the lateral ventricle,infarction volume was reduced,the expression levels of pro-inflammatory factors tumor necrosis factor alpha and nuclear factor-kappa B in the cerebral cortex were decreased,and neurological functioning was improved.These findings suggest that lipoxin A4 has strong neuroprotective effects in diabetes mellitus complicated by focal cerebral ischemia/reperfusion injury and that the underlying mechanism is related to the anti-inflammatory action of lipoxin A4.     

Selective platelet deposition during focal cerebral ischemia in cats

Platelet deposition in the microcirculation may play a role in focal cerebral ischemia. We investigated platelet deposition in selected parts of the cat brain after temporary middle cerebral artery occlusion. Ten anesthesized cats were given autologous indium-111-labeled platelets and chromium-51-labeled erythrocytes. The right middle cerebral artery was occluded with miniature aneurysm clips for 3 hours via a transorbital approach; blood pressure was reduced concomitantly to decrease the collateral circulation. Removal of the clips initiated a 45-minute period of normotensive reperfusion. After sacrifice, the brain was removed and sectioned for comparison of right- versus left-hemisphere platelet deposition. Platelets were selectively deposited in the territory of the occluded right middle cerebral artery. Significant deposition was found in the caudate nucleus, internal capsule, parietal cortex, and the centrum semiovale. Our findings support the evidence that platelets are deposited in the microvasculature during temporary severe focal cerebral ischemia.     

Regional differences in rat brain lipids during global ischemia.

BACKGROUND AND PURPOSE: Membrane lipid degradation plays an important role in the pathogenesis of ischemic brain damage, but there is little information on changes in cerebrosides, sulfatides, and sphingomyelin. We studied regional changes in the quantities of these lipids during complete global brain ischemia in rats. METHODS: Nitrous oxide-anesthetized rats were subjected to ischemia by a high-pressure neck cuff and arterial hypotension for 0 (control), 3, 10, or 30 minutes (n = 5 at each time). Brain temperature was allowed to fall spontaneously during ischemia, and the brain was frozen in situ with liquid N2 without recirculation. The frontal cortex, hippocampus, and basal ganglia were dissected at -15 degrees C. The lipids were separated by column and high-performance thin-layer chromatography and quantified by charring and densitometry. RESULTS: Total lipid content was higher (p less than 0.01) in the hippocampus (72.6 +/- 2.8 mg/g wet wt, mean +/- SD) than in the frontal cortex and basal ganglia (57.7 +/- 2.1 and 62.6 +/- 1.5 mg/g wet wt, respectively). Ischemic changes occurred only in the frontal cortex, where total lipid content fell (p less than 0.01) by 11% after 30 minutes of ischemia because sulfatide and cerebroside contents fell by 44% and 38%, respectively. CONCLUSIONS: Despite a marked accumulation of free fatty acids during complete global brain ischemia in rats, the only detectable changes in brain lipids were in the amounts of cerebrosides and sulfatides in the frontal cortex.