To evaluate the changes after in vivo ketone body metabolism of cerebral ischemia / experimental model of cerebral ischemia-reperfusion in Wistar rats common carotid artery (CCAS a) to be caused by simple obstruction.
Method: 40 - 8 Wistar male rats randomly into two groups: two systems (S Normal - Siam; products - test) and further research was redistributed to a set of four times. CCAS 30 minutes after bilateral occlusion of the T group animals showed reperfusion in 0,5,10,15 minutes. Acetoacetate metabolism and systemic arterial blood samples and brain tissue (ACT) a, β-(BHB) --hydroxybutyric acid was determined to collect.
Result: The brain levels of ACT and BHB group T significantly blocked carotid artery in 30 minutes (time 0) after an increase. Ketone bodies in the brain of the 10 best minutes after the circulation (ACT's + BHB) concentrations was tested in 5 min reperfusion, decreased. Between groups increased by a similar test with a fake body ketone body levels. S 40 is set after the main body and the brain demonstrated a significant increase in ACT and BHB concentrations - 45 studies.
Conclusion: Acute global cerebral ischemia partially Wistar temporary stimulant to trigger catecholamine secretion induced ketogenesis probably bilateral carotid artery occlusion in rats. Increase in ketone bodies in brain ischemia, brain uptake, as an alternative energy, as well as stress conditions was confirmed in brain metabolism of these metabolites, the neuroprotective under its potential role board. As a result of reperfusion phenomenon is verified in the early minutes of the biggest changes in ketone body metabolism, circulation.
Introduction:
Ketone bodies Corporation (KBS) D - 3 are associated with insulin resistance and hunger play a role in the (D - 3HB) and acetoacetate (AcAc) hydroxybutyric acid. Insulin dose, KBS-response relationship between the type and the right has been proven to be two shifts of patients with diabetes. However, to reduce obesity levels have been reported in bytes. We and obese men during the fasting blood glucose and glucose-2 diabetes and stable D - 2 in lean fasting 3HB input without using the isotope 38 KB respect the metabolism of the pancreatic clamp procedure after hours Then the study of metabolic adaptation. We are in the ground state D - 3HB in the obese men had higher flux: 7.0 versus 15.2 (10.7 to 27.1) (3.5 〜 15.1) micromol / (Lake Biwa) Ã- minutes, respectively, P kg lean body mass compared found in red meat "0.01. Kirobaitofurakkusu pancreatic clamp time difference between lean and obese volunteers and not (Step 1: The Discovery 6.9 (1.8 to 12.0) 7.4 versus (4.2 〜 17.8) micromol / Ã- min Biwa kg, respectively, step 2:2.9 (0 -7.2) 3.4 vs (0.85 - 18.7) micromol / Ã- Biwako kg min, respectively), despite similar plasma insulin levels. Meanwhile, the high peripheral glucose uptake become obese men (15.2 versus step 1:14.7 (12.3 to 25.6) (11.9 〜 22.7) micromol / Ã- Biwako min kg, respectively, P "or = 0.05; and Step 2: Lean compare 12.5 (7.0 to 17.3 ) 10.8 vs. (5.2 〜 15.0) micromol / kg X minute of Lake Biwa, respectively, P "or = 0.01). These data are the subject of obesity is mediated peripheral glucose uptake show insulin resistance to insulin The show has the same sensitivity and reduce insulin-mediated ketogenesis. This is not obese, it means the difference between intermediary metabolism and insulin sensitivity.
Stroke is the leading cause of death in the world is the second three. Represents a major cause of death and disability in the elderly with ischemic stroke. Most stroke survivors disability.1 life at the moment, recombinant tissue plasminogen activator only (angle - PA) stroke.2 effective range of acute ischemic damage and exogenous nature of our management The main objective of the ongoing study of strokes representing the remaining are labeled for understanding the role of pathogenic factors. Development of experimental model of cerebral ischemia, which allowed a better knowledge of the pathophysiology in this direction, a new treatment for strategies.3 test a variety of rodent models of cerebral ischemia / reperfusion proposed .4 2 is easier and has been vascular occlusion model allows greater scope for recovery experiments to perform less intrusive surgical intervention. However, ischemic events in several previous studies in rats, through the circle of Willis, a large collateral circulation is abundant, and the cortical branch anastomosis to achieve the end justify the reported failure of this model is nevertheless internal and external carotid system in these animals.5, we recently, in rat experimental model of cerebral ischemia is described in several changes in the metabolic pathway of oxidative phosphorylation and glycolysis caused only by bilateral occlusion of common carotid artery. This approach, the evidence, blood sugar, nevertheless, energy, brain demands.6 meet the main board, but some evidence of the brain (ACT) a, β-(BHB) -- hydroxybutyric acid, ketone bodies acetoacetate as an alternative (KB) substrates under conditions of stress on energy metabolism of the brain that use. Direct the use of ketone bodies in the brain, is usually very low, but that depends on blood levels, significantly increased extreme damage (trauma, stroke, hypoxia). KB and diffusion of these substances in the blood is a major production site, was taken to nearby tissue, and liver. Kg brain metabolism, blood-brain barrier permeability is regulated by a wealth of monocarboxylate transporter-dependent. Role in regulating KB metabolism of neurons and glial cells of the monocarboxylate transporters are present in the cell membrane is unknown. Finally, brain.7 cerebral metabolic rate for miles after a change in the in vivo ketone body metabolism of cerebral ischemia to evaluate the relevant studies in the presence of the enzyme / activity of reperfusion, cerebral ischemia simple occlusion of the carotid arteries of rats depends on the experimental model through.
Cerebral ketone body metabolism.
During the neonatal period, they are also lipids (especially cholesterol) and is a precursor for the synthesis of amino acids. Kg of brain metabolic rate that occurs during fasting and high-fat diet and high levels of concentration in the blood mainly depends. Kg brain metabolism, permeability of the blood-brain barrier (BBB rank), the monocarboxylate transporter (MCT1) is regulated by the extensive reliance. KBS's human fasting and increased BBB permeability in the ranking. In rats, permeability increases during the period rather than mammals, are not considered a human baby. The monocarboxylate transporter, the role of neurons and glia in regulating KB metabolism is present in the cell membrane is unknown. Finally, the metabolic rate of brain kilometers, depending on the activity of related enzymes in the brain. Activities, the age of the rats is not different from human use and reliable results. Kg human brain metabolism is different in some respects the rat. When hungry, for example, KBS will specify the details of the energy of the human brain compared to rats. Conversely, KBS will be used in the mammalian brain in newborn rats than in humans probably more widespread. These differences complicate the interpretation of rodent studies. Most patients with congenital ketone is usually, KBS and suggests that it is developing as an alternative fuel during long-term illness or fasting an important role only for. While the HMG-, - CoA lyase deficiency is in image processing, shows white matter abnormalities generally asymptomatic. KBS has the ability to act as an alternative fuel, and its effectiveness remains unknown cause epilepsy in GLUT1 deficiency is explained by the effect of the ketogenic diet.
Metabolism of ketone bodies by skeletal muscle in starvation and uncontrolled diabetes
In previous studies, skeletal muscle ketone bodies (KB) of 25% has been suggested as a possible charge of production in uncontrolled diabetes. In the current study, acetoacetate (AcAc) and β-hydroxybutyrate production in diabetic patients was quantified from the arterial and venous catheter placement surgery of insulin conscious dogs hind leg (n = 5) and 4 days fasting withdrawn (n = 7) is a dog. Modeling of two swimming pools, ^ "13" and 14C ages acetoacetate β-(βOHB) has been employed to quantify the speed of the entire hindlimb kg using simultaneous injection hydroxybutyric acid. 39.3μmol • kilobytes total production and 9.4 kg - 1 • min - 1, in fasting and diabetic animals was, respectively. Both groups were ignored in the production of hind limb kg. 2 - The model estimates the pool of available kilobytes hindlimb artery was then obtained by calculating the difference between similar vein. In conclusion, hindlimb KBS dog does not contribute to diabetes and de novo synthesis of one of starvation. The metabolism of bytes, from the difference between species occurs may be the site for KB production potential of human muscle.
Methods
Animals
40 - 8 healthy male Arubinouisutaratto (Mammalia Rodentia, rodents, Dobunezumiarubinusu) Central Bioterium obtained from the Federal University of Ceara, 406.23 ± 52.21 grams, the metric used in this study. All animals are the same breed, and maintained a laboratory in a controlled environment. Research for the International Council for Laboratory Animal Medicine in compliance with ethical guidelines for the care and handling procedures and processing of all rats (CIOMS - according WHO) is. Obtained from animal research ethics committee of the Federal University of Ceará approved the experimental use of laboratory animals.
Research Design
Animal fair at random in two groups (24 rats each) were distributed in: Group S normal (false) or group product (test). Four subgroups in each group (6 rats each were distributed), that set a different time of the study. All T-group of animals from surgery was 30 minutes into the common carotid artery (CCAS a) between the two countries, including obstruction of 0 (zero), and submit in a few minutes reperfusion 5,10,15 was. S in all groups of animals from surgery, CCAS obstruction between the two countries, and groups were submitted to T set than the equivalent period of study
Surgical
All procedures under anesthesia, ketamine chlorhydrate (90 mg / kg) and xylazin (10mg/kg) was made on the association between the administration of intra-abdominal cavity. Initially, the CCAS executed cervicotomy frontal mediana be separated from the surrounding connective tissue and nerve fibers were carefully exposed. T group of rats were submitted to the simultaneous addition, the group S only obstructed animals () is, without at the same time the CCAS CCAS isolation between the two countries in the 30 minutes of the clamp using the aneurismal clips between the two countries. After this, the central artery and later by the separation of arterial dissection and abdominal aortic punction of the frontal mediana after being effectuated. Finally, dual flexible grinding wheel extensive craniectomy, turn off the electric micro-motor is running 20,000 rpm to connect with the face, then, hemispheres.6 published the brain
Brain and blood samples
Brain tissue samples (randomly chosen) and the central arteries (abdominal aorta), left hemisphere ischemic end of 15 minutes (time 0) and the 5th 10:00 aneurismal clip (perfusion) were collected after opening. The pretense is after 30,35,40 These samples were obtained CCAS bilateral occlusion of the isolation () instead of after the rats operated according to established pre-set time of 45 minutes studying. Brain samples for biochemical analysis back immediately frozen in liquid nitrogen. Glass vials placed in a blood sample containing 10% perchloric acid, deep freeze until use.
Biochemical analysis
Acetoacetate (ACT) a, β-(BHB) in the way of biochemistry of the brain and blood samples were assayed according to published elsewhere.8 acid concentration
Statistical analysis
Ketone bodies (ACT the BHB and ACT + BHB) concentrations were calculated as μmol / g fresh brain tissue and in μmol / mL blood and results were expressed as the median of another group. Mann - Whitney non-parametric test (U test) was used for statistical analysis. Statistical significance was accepted as p "0.05.
Results
ACT group systemic levels of T significantly at 30 minutes after the occlusion CCAS between the two countries (133.3% - 0 hours) and increased at 5 min reperfusion (78.6 percent), 10 minute cycle (42.7% decrease in ). S 45 surgical group (30 +15 min) (Fig. 1) of the body only after the ACT (78.4%) announced a significant increase. 0 BHB concentrations in blood remained low in 5min reperfusion showed significant and 10:00 (97.4%) and increased 15 minutes (or 41.5%) was recycled. Sham group general surgery operations BHB 35 minutes (30 +5 min) (Fig. 2) after (145.9 percent) showed a significant and permanent increase. Joint analysis (ACT's + BHB) and group S and group T showed significant levels of systemic kilobytes, as well as fake 10 groups except for increased concentration of high-byte min reperfusion (Figure 3) compared with did. ACT brain levels of T significantly in group 30 minutes after carotid occlusion (204.2 per cent - 0 hours) and increased at 5 min reperfusion (more than 152.0 percent), 10 significantly reduced the time (76.6%) and 15 minutes (32.5%) or recycled. 15 minutes of reperfusion, this decreased significantly to 83.8% when the S group was compared at this point in the brain of the group forged a significant increase in concentration of ACT 10 (206.4 percent) and 15 minutes (88.4%) re - Details of the perfusion (Figure 1 display). Brain BHB concentrations 30 minutes (1,146.1%) decreased significantly in five of the clamp increased significantly immediately after going to control the level of min reperfusion. S 45 only after the surgery group, the first level (30 min - time 0) (Fig. 2) compared with brain BHB concentration (192.3 percent) announced a significant increase. Binding analysis in (ACT + BHB) 30 of the group of T minutes after clamping of the carotid artery demonstrated a significantly increased brain levels of kilometers, 5min in circulation (869.2 percent) for each control (group S) compared with the means that. Subsequent reperfusion, we) and 15 byte level decreased significantly at 10 minutes (37.0% observed (53.8% more), the average concentration compared with 5min verified circulation. Sham group, the level of the brain byte shows a significant increase (392.3 percent) means that after 40 - 45 levels before surgery (Figure 3) were compared.
Discussion
However, the biochemical effects of acute stress, strokes and some, well, that is described in the instructions that are to changes in the metabolism of ketone bodies and relatively little interest. Ketone bodies (KB) concentrations in the blood and cerebral metabolic rate of kilometers an important source of energy in the brain is dependent on the Lord. Acetoacetate (ACT) to acetyl CoA is derived from fatty acid oxidation than the formation of, β-(BHB) - Acute ACT.7 now hydroxybutyrate ketone is usually generated by the current knowledge about the metabolic stress reduction considers decreased after injury. This mechanism appears to have been achieved not fully understand this, and related to increased insulin / glucagons levels of inflammatory mediators, in particular, IL - 1.9 subacute stress while other / In the chronic phase, the tissue injury triggers enhanced glycolytic () to decrease insulin resistance, decreased plasma insulin concentration, insulin to promote the use of high ketogenesis.7 - 9 Nevertheless, the activation Google search results CCAS 30 minutes in rats after bilateral occlusion of the (time 0, demonstrated an increase in the concentration of the whole ACT) is a decrease in cerebral blood flow occurred ACT synthesis in the liver to trigger the corresponding show. As a review of the literature up until now as it will appear after acute brain injury in the first experimental demonstration of activation of this ketone. Tamaki et al.10, studying the biochemical changes after acute severe head, injury, and increased plasma concentration of patients indicate that km was due to a rise in catecholamine levels may find this also obvious. In addition, the correlation between the degree of severity of head injury to blood ketone by these authors. Keller et al.11 are three levels of plasma norepinephrine results from a combination of two factors hyperketonemic Effects: liver fatty acid supply to the expansion fee (FFA) increased production of ketone bodies from; demonstrate accelerated hepatic ketogenesis, and conservative decreased metabolic clearance of ketone bodies. At this point, Hakanson et al.12, the systemic injection of epinephrine while those from KB and FFA levels, we established the induction of the marked increase than seen immediately after surgery. These findings were supported by Cutherbertson, this is a postulate of the stress response to acute stress reaction hypothesis of Bessman in two phases, the phase of catecholamines and pituitary - adrenal system phase. This reaction, or acute stress glycogenolysis, or breakdown of fat and glycogen, catecholamine-induced fat from glucose to ketone (so-called "injury is the flow of metabolic reaction stage called") from is deemed by ketones are generated for glucose and ketone bodies increased during the subacute gluconeogenesis.13 despite ample published data to compare the current results, the authors, the rat In order ketogenesis could have acute global cerebral ischemia, bilateral carotid artery occlusion triggers catecholamine secretion stimulant is recommended that the following. Alternative substrate of glucose addition, 30 minutes after the increase in the ACT and BHB, the level of brain energy metabolism between the clamp CCAS is to use these substances, also shows affinity for brain tissue injury, ischemic event Some indicated that, since the uptake is not blocked carotid artery occlusive cerebral kg. Collateral circulation in the rat large rich post is actually observed as brain barrier permeability of the blood increased ischemic, cerebral ischemia reperfusion.4 - 6 In recent studies, ACT has been pointed out strengthened following the occurrence of, and may explain this finding BHB during hypoxic brain functions as the brain and improved neuroprotective damages.14 interesting combination of body and brain after carotid clamping ACT increasing the concentration of KB did not confirm the improvement of ischemic agents in rats and humans confirm the importance of oxygen deficiency level BHB: BHB concentration in blood is initially low and high levels of the brain. This causes the ACT, was sent to the ischemic brain tissue quickly, only then, was to mobilize the local system BHB initial decline. In addition, more than a group of metabolic changes in T is obviously expected to reduce the brain damage induced by the level of non-ischemic, partially this phenomenon, since the concentration of BHB in the blood during the test and sham groups can be proposed to clarify the byte-level similarity of the whole body attractive. The highest concentration of 5 kg brain minutes after reperfusion, primarily the brain, ACT to the enhancement of the brain metabolic changes are probably more important, to indicate that occurs at this point has been verified. In our previous report, this trend is evident when the author is also affected by this discovery because of reperfusion injury creates a state of absence of oxygen and energy metabolism is not restored to normal, inflammation and oxidative damage restoration of circulation results function.15 Nevertheless, ACT and BHB levels in the brain, suggesting that it was transient ischemic reperfusion injury, decline in circulation after 10 minutes, glucose-based energy metabolism was collected, perhaps the last part, after reperfusion following. On the other hand, the whole brain and increased levels of ACT and BHB 40, after the main study group of 45 false minutes of these groups in group T in order to observe the set time corresponding to the body and brain S byte-level equalization. That this expansion of acute ischemic rat ketogenesis non-invasive procedure extended experimental surgery (mainly craniectomy), probably the same biochemical mechanisms of these ischemic / reperfusion brain injury described by Save the trigger shows to be caused by time.13
Conclusions
Bilateral carotid artery center of the initial stimulusocclusion in Wistar rats, following the launch for catecholamine secretion probably ketogenesis acute global cerebral ischemia some temporary.
increase in ketone bodies, the uptake of the brain (acetoacetate and β-hydroxybutyric acid), following cerebral ischemia, as alternative energy, as well as stress conditions was confirmed brain metabolism of these metabolites, The neuroprotective board below their potential role;
recirculation been validated in the early minutes of the biggest changes in ketone body metabolism, behavior characteristics of reperfusion
