Plasmodium berghei infection: dichloroacetate improves survival in rats with lactic acidosis

The kinetics of Plasmodium berghei infection and the development of lactic acidosis, hypoglycemia, and anemia were defined in young Wistar rats. This model of metabolic dysfunction, which is similar to that of severe human malaria, was used to test the hypothesis that dichloroacetate, a treatment for lactic acidosis, prolonged survival in rats receiving a single antimalarial dose of quinine (20 mg/kg). Rats with hyperlactatemia (lactate > 5 mmol/liter, N = 183) were randomized to receive either dichloroacetate (100 mg/kg, N = 99) or saline (N = 84) and were monitored for outcome (survival or death) for 50 hr. Logistic regression modeling adjusting for baseline venous lactate concentration demonstrated that dichloroacetate increases survival rates in rats with venous lactate concentrations between 5 and 8.9 mmol/liter (odds ratio > 2.2, P < 0.021). This is the first demonstration that specific intervention to treat lactic acidosis can prolong survival and suggests that dichloroacetate may be useful as adjunctive therapy in the management of lactic acidosis complicating severe falciparum malaria.

Short-term dichloroacetate treatment improves indices of cerebral metabolism in patients with mitochondrial disorders

We performed a short-term, double-blind, placebo-controlled, crossover trial of sodium dichloroacetate (DCA) therapy in 11 patients affected by various primary mitochondrial disorders. Independent measures of oxidative metabolism (venous blood metabolites, exercise testing, phosphorus magnetic resonance [MR] spectroscopy of muscle, and proton MR spectroscopy of brain) were used in order to monitor metabolic responses to the drug. One week of DCA treatment produced significant decreases (p < 0.05) in blood lactate, pyruvate, and alanine at rest and after bicycle exercise. Proton MR spectra collected from a supraventricular volume of interest in brain of seven of 11 patients also showed significant changes. Brain lactate/creatine ratio decreased by 42% during DCA treatment (p < 0.05). Brain choline/creatine ratio (which is low in patients with myelinopathies) increased by 18% (p < 0.01) after therapy. N-Acetylaspartate/creatine ratio (an index of neuronal damage or loss) increased by 8% after treatment (p < 0.05). Proton MR spectra collected in two of 11 patients from a volume of interest including the basal ganglia showed similar results (decrease of 36.6% in lactate/creatine; increases of 16% in choline/creatine and 4.5% in N-acetylaspartate/creatine). Phosphorus MR spectroscopy of muscle and self-assessed clinical disability were unchanged. Our study indicates that short-term DCA treatment not only lowers blood lactate but also improves indices of both brain oxidative metabolism and neuronal and glial density or function.

Pharmacokinetics and pharmacodynamics of dichloroacetate in children with lactic acidosis due to severe malaria

Lactic acidosis frequently complicates severe malaria in African children, and is a strong independent predictor of mortality. We tested the hypothesis that sodium dichloroacetate (DCA), an activator of pyruvate dehydrogenase, rapidly reduces hyperlactataemia in this patient population. Eighteen children with severe malaria and capillary plasma lactate > or = 5 mM were randomized to receive either intramuscular quinine plus a single 50 mg/kg intravenous infusion of DCA in saline, or quinine plus intravenous saline alone. Two patients in each treatment group died following randomization. Thirty minutes after treatment, the mean plasma lactate was 28% below pretreatment baseline values in the DCA group, but was unchanged in the placebo group. Throughout the first 4 h after treatment, mean plasma lactate in the DCA-treated patients was significantly less than that in controls (p = 0.003). Thereafter, mean plasma lactate declined in both groups and was < 2 mM 10 h after treatment. DCA was well tolerated and did not alter quinine pharmacokinetics. A single intravenous dose of DCA rapidly improved lactic acidosis in African children with severe malaria, suggesting that DCA may be a useful adjunct in the initial treatment of these patients, and may increase their chance of survival by improving a major complication of their illness.

Congenital lacticacidemia caused by lipoamide dehydrogenase deficiency with favorable outcome

A 5-year-old boy had recurrent vomiting and lethargy with lacticacidemia and ketoacidemia since birth. Lipoamide dehydrogenase deficiency was found in muscle and fibroblasts. Therapy with sodium dichloroacetate, thiamine, and carnitine was associated with reduction of the severity and frequency of the decompensation episodes and near normal plasma lactate levels. At 5 years of age, the patient has normal cognitive function and moderate motor impairment.

Amelioration of lactic acidosis with dichloroacetate during liver transplantation in humans

BACKGROUND

Marked lactic acidosis occurs during orthotopic liver transplantation (OLT), especially during the anhepatic phase. Current standard therapy is NaHCO3, although it may exacerbate intracellular acidosis, increase plasma lactate, and contribute to hypernatremia. Alternatively, dichloroacetate (DCA) stimulates pyruvate oxidation in vivo, reduces plasma lactate, and moderates intracellular acidosis. The aims of this study were to test the efficacy of DCA to control lactic acidosis, reduce the NaHCO3 requirement and incidence of hypernatremia, and stabilize perioperative acid-base homeostasis. Others aims were to examine the DCA pharmacokinetic profile during OLT and the role of lactate metabolism in OLT-associated hyperglycemia.

METHODS

Patients (n = 66) for OLT were divided into two equal groups to receive or not receive DCA during OLT. DCA 40 mg.kg-1 was infused over 60 min after induction of anesthesia and 4 h later. Plasma DCA concentration was measured by gas chromatography-mass spectroscopy, and pharmacokinetics were assessed by a one-compartment model. Serial arterial blood gases, lactate, Na+, glucose, and hemodynamic measurements were compared, as were intraoperative utilization of blood products, CaCl2, and NaHCO3.

RESULTS

Plasma DCA concentration was maintained between 0.28 and 1.18 mM during OLT, with peak concentrations of 0.73 +/- 0.06 (mean +/- SE) and 1.18 +/- 0.09 mM, respectively after the first and second doses. In control patients, plasma lactate was 1.07 +/- 0.04 at baseline and 1.20 +/- 0.06 before incision and reached a peak of 7.30 +/- 0.41 mM after graft reperfusion. In DCA-treated patients, the respective values were 1.07 +/- 0.06 (difference not significant), 0.63 +/- 0.05 (P < 0.001), and 3.39 +/- 0.20 (P < 0.001) mM. Intraoperative changes in arterial blood pH, HCO3(-1), and base excess were comparable though less marked in DCA-treated patients, whose NaHCO3 requirement was reduced (0.59 +/- 0.36 vs. 2.83 +/- 0.53 mEq.kg-1 in control patients, P < 0.001). There was no difference between groups in requirements for CaCl2 or blood products, in intraoperative hemodynamics, in duration of the surgical stages, or in graft ischemia times. Twelve control and 4 DCA-treated patients exhibited a plasma Na+ concentration > 145 mEq/1 at completion of surgery (P < 0.05). Hyperglycemia was not attenuated by DCA despite decreased plasma lactate concentration. Sixteen and 28 h after graft reperfusion, when plasma DCA had been eliminated, plasma lactate and degree of metabolic alkalosis did not differ between groups.

CONCLUSIONS

DCA safely and effectively attenuated lactic acid accumulation and moderated acidosis during OLT. DCA decreased the requirement for NaHCO3 therapy and the incidence of hypernatremia. OLT-associated hyperglycemia did not result from lactate-induced stimulation of hepatic gluconeogenesis. Postoperative metabolic alkalosis was not substantially influenced by lactate metabolism.

Enhanced glucose oxidation in exercise-induced myocardial ischemia

BACKGROUND

In animal models, dichloroacetate (DCA) facilitates recovery from severe myocardial ischemia by stimulating glucose oxidation.

OBJECTIVE

To evaluate the acute efficacy of DCA as a metabolic anti-ischemic intervention in patients with coronary artery disease (CAD) and exercise-induced myocardial ischemia in a clinical trial.

METHODS

Double-blind, randomized, crossover comparison of single dose (50 mg/kg intravenously) DCA versus placebo on clinical and electrocardiographic variables in seven patients with single vessel CAD and 34 patients with multiple vessel CAD during standard dynamic exercise testing.

RESULTS

Blood pressure did not differ with placebo or DCA but mean heart rate was higher with DCA at rest (62 versus 59, P < 0.004) and at 5 mins of recovery (78 versus 75, P < 0.02). Exercise duration averaged 538 s with DCA and 534 s with placebo (not significant). Chest pain occurred in 14 patients in both tests, clinical ST depression occurred, in 34 placebo tests and 37 DCA tests (not significant). Body surface potential maps (BSPM) of the decrease in the area under the ST curve from rest to peak exercise averaged -5096 microV's with DCA and -5159 microV's with placebo (not significant). BSPM at 1 and 5 mins postexercise also showed no differences in rate of ST integral recovery.

CONCLUSIONS

In the transient regional model of human myocardial ischemia induced by dynamic exercise, the acute administration of the pyruvate dehydrogenase agonist DCA was not associated with clinical or electrocardiographic moderation of, nor accelerated recovery from, ischemia. Whether DCA or metabolically similar agents that enhance oxidative metabolism are beneficial in other ischemic settings, such as the no-flow states of acute ST elevation myocardial infarction or angioplasty, requires further systematic evaluation.

Dichloroacetate for lactic acidosis in severe malaria: a pharmacokinetic and pharmacodynamic assessment

Lactic acidosis and hypoglycemia are potentially lethal complications of falciparum malaria. We have evaluated the pharmacokinetics and pharmacodynamics of dichloroacetate ([DCA], 46 mg/kg infused over 30 minutes), a stimulant of pyruvate dehydrogenase and a potential treatment for lactic acidosis, in 13 patients with severe malaria and compared the physiological and metabolic responses with those of a control group of patients (n = 32) of equivalent disease severity. The mean +/- SD peak postinfusion level of DCA was 78 +/- 23 mg/L, the total apparent volume of distribution was 0.75 +/- 0.35 L/kg, and systemic clearance was 0.32 +/- 0.16 L/kg/h. Geometric mean (range) venous lactate concentrations in control and DCA recipients before treatment were 4.5 (2.1 to 19.5) and 5.5 (2 to 15.4) mmol/L, respectively (P > .1). A single DCA infusion decreased lactate concentrations from baseline by a mean of 27% after 2 hours, 40% after 4 hours, and 41% after 8 hours, compared with decreases of 5%, 6%, and 16%, respectively, in controls (P = .032). These changes were preceded by rapid and marked decreases in pyruvate concentrations. Arterial pH increased from 7.328 to 7.374 (n = 10, P < .02) 2 hours after the infusion. Hypoglycemia was prevented by infusing glucose at 3 mg/kg/min. There was no clinical, electrocardiographic, or laboratory evidence of toxicity. These results suggest that DCA should be investigated further as an adjunctive therapy for severe malaria.

Improved hemodynamic function and mechanical efficiency in congestive heart failure with sodium dichloroacetate

OBJECTIVES

The purpose of this study was to determine whether sodium dichloroacetate improves hemodynamic performance and mechanical efficiency in congestive heart failure.

BACKGROUND

Congestive heart failure is associated with impaired hemodynamic performance and reduced mechanical efficiency. Dichloroacetate stimulates pyruvate dehydrogenase activity by inhibition of pyruvate dehydrogenase kinase, which results in inhibition of free fatty acid metabolism and stimulation of high respiratory quotient glucose and lactate consumption by the heart. Facilitation of glucose and lactate consumption with dichloroacetate should improve mechanical efficiency of the failing ventricle.

METHODS

Ten patients with New York Heart Association functional class III to IV congestive heart failure were studied. Dichloroacetate (50 mg/kg body weight) was administered intravenously for 30 min, with measurements of hemodynamic variables, coronary sinus blood flow and blood gas, glucose and lactate levels for 2 h. The same patients were also given dobutamine (5 to 12.5 micrograms/kg per min) for comparison.

RESULTS

Therapeutic levels of dichloroacetate were achieved (100 to 160 micrograms/liter of plasma). Myocardial consumption of lactate was stimulated from 29% to 37.4%. Forward stroke volumes increased (+5.3 ml/beat, p < 0.02), as did left ventricular stroke work (+1.8 g-m/m2 per beat, p < 0.02) and left ventricular minute work (from 1.38 to 1.55 kg-m/m2 per min, p < 0.01). Myocardial oxygen consumption decreased (from 19.3 to 16.5 ml/min, p = 0.06) as left ventricular minute work increased. Left ventricular mechanical efficiency thus improved from 15.2% to 20.6% (p = 0.03). Dobutamine administration resulted in the opposite trend with respect to myocardial lactate extraction (from 34% to 15.3%, p < 0.02). Stroke volume increased (+7.4 ml/beat, p = NS vs. dichloroacetate), as did left ventricular minute work (from 1.29 to 1.59 g-m/m2 per min, p < 0.01 vs. dichloroacetate) and myocardial oxygen consumption (from 18.6 to 21.0 ml/min, p = 0.06 vs. dichloroacetate). Left ventricular mechanical efficiency did not change with dobutamine administration (from 16.4% to 15.8%, p = NS).

CONCLUSIONS

Dichloroacetate administration stimulates myocardial lactate consumption and improves left ventricular mechanical efficiency. Forward stroke volume and left ventricular minute work increase significantly, with a simultaneous reduction in myocardial oxygen consumption. Dobutamine administration results in similar hemodynamic improvements but with no change in left ventricular mechanical efficiency and with opposite effects on lactate metabolism. The opposing metabolic actions, yet similar hemodynamic responses, of dichloroacetate and dobutamine suggest that these agents may be complementary in the treatment of congestive heart failure.

Hypertriglyceridemia in experimental diabetes: relationship to cardiac dysfunction

The incidence of mortality from cardiovascular disease is higher in diabetic patients. The objective of the present investigation was to test the hypothesis that the diabetes-induced depression in cardiac function may be due to hypertriglyceridemia. Hyperlipidemia and a depressed left ventricular developed pressure and rate of increase and decrease of ventricular pressure (+/- dP/dt) were produced in isolated hearts from rats made diabetic with streptozotocin compared with hearts from control animals. This depressed cardiac performance was successfully prevented by hydralazine treatment (for 3 weeks), which also lowered plasma triglyceride levels and suggested that hyperlipidemia may be important in altering cardiac function in experimental diabetic rats. The beneficial effects of clofibrate, verapamil, prazosin, enalapril, and benazepril administration were then studied in diabetic rats. The treatments (with the exception of enalapril) significantly reduced plasma triglyceride levels but did not prevent the onset of heart dysfunction in chronically diabetic rats. These studies suggest that in the chronically diabetic rat, hypertriglyceridemia may not be as important as previously suggested, in the development of cardiac dysfunction. Since acute dichloroacetate perfusion improves cardiac function in 6 week (but not 24 week) diabetic rats, it appears more likely that improving myocardial glycose utilization is more critical than triglyceride lowering, in preventing cardiac dysfunction in the diabetic rat at this time point.

The limiting effect of dichloroacetate on endotoxin-induced liver damage in starved rats

Dichloroacetate has been shown to have therapeutic effects on sepsis and endotoxin shock and to reduce liver damage in rats intoxicated with ethanol or carbon tetrachloride. In this study, the effect of dichloroacetate on endotoxin hepatitis was investigated. Endotoxin hepatitis was induced by an intraperitoneal coadministration of 50 micrograms/kg lipopolysaccharide from Escherichia coli, and 200 mg/kg D-galactosamine in starved, male Wistar rats. This treatment induced the following changes within 24 hr: an increase in the serum aminotransferase activity, histological alterations of the liver including focal necrosis of liver cells and inflammatory infiltrates, an increase in blood pyruvate and alanine concentrations, and inhibition of starvation ketosis. The intraperitoneal administration of 250 mg/kg dichloroacetate 30 min after the administration of the toxins partially counteracted all of these changes. The administration of dichloroacetate might be useful in coping with hepatic damage as well as lacticemia and cardiovascular depression induced by endotoxins.

The use of dichloroacetate in the treatment of overwhelming hypoxic acidosis

Overwhelming hypoxic acidosis due to poor tissue oxygen delivery from low cardiac output, pulmonary failure, and other causes has devastating effects postoperatively on patient outcome. Whereas conventional therapeutics often can not reverse the downward spiral of these patients, dichloroacetate (DCA) has been shown to be beneficial. This study investigated the metabolic and hemodynamic effects of DCA given after the onset of overwhelming hypoxic acidosis in a canine model. A hypoxically ventilated canine model of severe induced acidosis was established and dogs surviving the development of acidosis were randomized to receive DCA or sodium chloride (NaCl) treatment. Dogs receiving DCA after development of hypoxic lactic acidosis showed no further change in metabolic parameters during the 90-minute treatment period (pH, 7.24 to 7.23; HCO3, 17.7 to 18 mmol/L; lactate, 2.04 to 1.05 mM/L); whereas animals receiving an equivalent sodium load showed progressive, significant deterioration in all parameters (pH, 7.24 to 7.12; HCO3, 16.8 to 13.2 mM/L; lactate, 2.05 to 3.55 mM/L). Myocardial blood flow was significantly increased by hypoxia in all dogs. Finally, cardiac output and stroke volume were significantly increased at 90 minutes by DCA versus control. Myocardial oxygen utilization efficiency (LV work/M VO2) was improved during DCA treatment. DCA, a carboxylic acid, increases pyruvate dehydrogenase activity, thereby enhancing lactate use a metabolic substrate. DCA had an ameliorative metabolic effect, and benefitted myocardial performance without a direct inotropic effect. DCA treatment appears to enhance myocardial performance on a metabolic and not primarily inotropic basis, does not increase the "cost" of myocardial work, and warrants further study.

Phenformin-induced lactic acidosis: a forgotten adverse drug reaction

OBJECTIVE

To document a case of severe metabolic and lactic acidosis secondary to phenformin. This adverse effect has almost been forgotten as 15 years have passed since its withdrawal from the US market.

CASE SUMMARY

A 64-year-old man presented with a four-day history of left upper abdominal pain and a one-week history of constipation and diarrhea. His arterial blood gases were pH 6.7, pCO2 2.80 kPa, and pO2 12.00 kPa with 90% oxygen saturation on room air. Serum chemistries indicated an unmeasurable serum bicarbonate concentration, anion gap 52 mmol/L, lactate concentration 29.5 mmol/L, blood urea nitrogen 6.63 mmol/L, creatinine 229.84 mumol/L, and blood glucose 4.35 mmol/L. There were low levels of urine and serum ketones. In the emergency department, he required resuscitation for hypotension and bradycardia. His diagnosis was lactic and ketoacidosis secondary to phenformin. The patient was treated with NaCl 0.9%, sodium bicarbonate, insulin, and hemodialysis. Although he survived the initial insult of lactic and ketoacidosis, his hospital course was complicated and he died on hospital day 105.

CONCLUSIONS

Treatment of lactic acidosis is difficult and challenging. The continued availability of phenformin in neighboring countries, and the renewed interest in biguanide therapy for treating diabetes mellitus make it an important diagnosis of exclusion in diabetic patients who present with severe acidosis. Metformin, another biguanide under investigation for the treatment of diabetes mellitus, is associated with a much lower incidence of lactic acidosis than is phenformin.

Transient improvement of congenital lactic acidosis in a male infant with pyruvate decarboxylase deficiency treated with dichloroacetate

A comatose male newborn infant with congenital lactic acidosis caused by pyruvate decarboxylase deficiency was treated with dichloroacetate (DCA), which stimulated an 88% drop in serum lactate concentration and reversed his coma. The response to DCA was temporary and the lactic acidosis worsened until his death, but DCA may confer more lasting benefit in less severely affected infants.

[Should bicarbonates still be administered in lactic acidosis?]

Bicarbonate administration during lactic acidosis seems logical in view of the myocardial depression associated with the decrease in intracellular pH. This treatment has been recently challenged on the basis of observations showing an increase in the veno-arterial gradient for CO2 during acute circulatory failure. The partial transformation of bicarbonate in CO2 carries the risk of aggravating the phenomenon and thereby decreasing intracellular pH. Alternatives to sodium bicarbonate--carbicarb, THAM and dichloroacetate--are discussed.

[Sodium dichloroacetate decreases the size of experimental myocardial infarction in dogs]

The effect of sodium dichloroacetate on the size of myocardial infarction and on the changes of blood lactate and pyruvate levels after coronary artery occlusion were studies in 5 dogs. Sodium dichloroacetate administrated during coronary artery occlusion in dogs limited the size of myocardial necrotic area, simultaneous decrease of lactate and pyruvate levels in peripheral blood was observed. An analysis of lactate levels in blood samples from the coronary sinus and left atrium during coronary artery occlusion and the administration of sodium dichloroacetate suggests that the utilization of lactate by left ventricular myocardium under these conditions is increased.

[Treatment of experimental ischemic cerebral lactic acidosis in rats with dichloroacetate]

In the cerebral ischemic pathophysiologic mechanism, lactic acidosis is a important factor to exacerbate cerebral damage. Our research showed that the lactic level of cerebral cortex in rats increased rapidly after the focal cerebral ischemia or during blood reperfusion after cerebral ischemia, 26.99 +/- 5.89 and 28.63 +/- 5.08 mumol/g brain wight respectively, it exacerbated significantly brain edema and pathological damage. The lactic level decreased rapidly to treat with dichloroacetate (50 mg/kg body weight) after cerebral ischemia or during blood reperfusion, 14.11 +/- 2.06 and 13.23 +/- 1.71 mumol/g brain wight respectively, brain edema and pathology improved significantly. It suggested that dichloroacetate might across blood-brain barrier into the cerebral ischemic region and lowered lactic level, improved brain internal environment, relieved cerebral damage after focal cerebral ischemia or during blood reperfusion. It may improve the prognosis of patient with ischemic cerebral vascular disease to be treated with dichloroacetate early.

A controlled clinical trial of dichloroacetate for treatment of lactic acidosis in adults. The Dichloroacetate-Lactic Acidosis Study Group

BACKGROUND

Mortality is very high in lactic acidosis, and there is no satisfactory treatment other than treatment of the underlying cause. Uncontrolled studies have suggested that dichloroacetate, which stimulates the oxidation of lactate to acetyl-coenzyme A and carbon dioxide, might reduce morbidity and improve survival among patients with this condition.

METHODS

We conducted a placebo-controlled, randomized trial of intravenous sodium dichloroacetate therapy in 252 patients with lactic acidosis; 126 were assigned to receive dichloroacetate and 126 to receive placebo. The entry criteria included an arterial-blood lactate concentration of > or = 5.0 mmol per liter and either an arterial-blood pH of < or = 7.35 or a base deficit of > or = 6 mmol per liter. The mean (+/- SD) arterial-blood lactate concentrations before treatment were 11.6 +/- 7.0 mmol per liter in the dichloroacetate-treated patients and 10.4 +/- 5.5 mmol per liter in the placebo group, and the mean initial arterial-blood pH values were 7.24 +/- 0.12 and 7.24 +/- 0.13, respectively. Eighty-six percent of the patients required mechanical ventilation, and 74 percent required pressor agents, inotropic drugs, or both because of hypotension.

RESULTS

The arterial-blood lactate concentration decreased 20 percent or more in 83 (66 percent) of the 126 patients who received dichloroacetate and 45 (36 percent) of the 126 patients who received placebo (P = 0.001). The arterial-blood pH also increased more in the dichloroacetate-treated patients (P = 0.005). The absolute magnitude of the differences was small, however, and they were not associated with improvement in hemodynamics or survival. Only 12 percent of the dichloroacetate-treated patients and 17 percent of the placebo patients survived to be discharged from the hospital.

CONCLUSIONS

Dichloroacetate treatment of patients with severe lactic acidosis results in statistically significant but clinically unimportant changes in arterial-blood lactate concentrations and pH and fails to alter either hemodynamics or survival.

Facilitating postischemic reduction of cerebral lactate in rats

BACKGROUND AND PURPOSE

Dichloroacetate facilitates a decrease in brain lactate during reperfusion after incomplete ischemia. This study examined the possible activation of pyruvate dehydrogenase enzyme by dichloroacetate to explain this effect. Because the duration of ischemia and hyperglycemia exacerbate ischemic brain damage, the effect of both of these factors on lactate reduction with and without dichloroacetate treatment after ischemia also was explored.

METHODS

The two-vessel occlusion and controlled blood loss model of stroke was applied to anesthetized rats. Samples of cerebral cortex were analyzed for lactate by enzyme fluorometry and for pyruvate dehydrogenase activity by radioassay.

RESULTS

Treatment with dichloroacetate produced no significant stimulation of pyruvate dehydrogenase after ischemia. When the duration of ischemia was increased or 50% glucose was infused before ischemia, brain lactate was significantly higher (p less than 0.01, Duncan's test). After 30 minutes of ischemia, treatment with a low dose of dichloroacetate (25 mg/kg) improved the reduction in lactate (p less than 0.01, Duncan's test).

CONCLUSIONS

These results indicate that although dichloroacetate reduces brain lactate after cerebral ischemia, the mechanism of action does not involve dichloroacetate's known ability to stimulate pyruvate dehydrogenase. However, these data support the use of dichloroacetate to lower cerebral lactate, especially in cases where ischemia is greater than or equal to 30 minutes in duration. They also suggest that early restoration and maintenance of perfusion after ischemia and discontinuing the use of 50% glucose before impending ischemia likewise would facilitate reduction of postischemic brain lactate.

Dichloroacetate

Dichloroacetate (DCA) represents a potentially novel class of oral antidiabetic agents that reduce blood glucose and lipids without stimulating insulin secretion. DCA reduces blood glucose by inhibiting hepatic glucose synthesis and stimulating glucose clearance and use by peripheral tissues. A major site of action of the drug is pyruvate dehydrogenase (PDH), the rate-limiting enzyme of aerobic glucose oxidation. Stimulation of PDH by DCA increases peripheral oxidation of alanine and lactate, thereby interrupting the Cori and alanine cycles and reducing the availability of three-carbon precursors for gluconeogenesis. In experimental models of ketosis, DCA reduces ketonemia and ketonuria while significantly lowering blood glucose. DCA inhibits hepatic triglyceride and cholesterol biosynthesis. Short-term studies in patients with non-insulin-dependent diabetes have demonstrated a capacity of the drug to markedly reduce circulating a very-low-density lipoprotein cholesterol and triglyceride concentrations. In genetic models of insulin-dependent diabetes, oral administration of DCA significantly reduces insulin requirements and blood levels of glucose and triglycerides. Several derivatives of DCA have been synthesized and found to have biological activity in animals. Further work is required to determine whether DCA and its analogues may be safe and effective agents for chronic treatment of the carbohydrate and lipid abnormalities of human diabetes.

Lactic acidosis, ketoacidosis, and energy turnover: "figure" you made the correct diagnosis only when you have "counted" on it--quantitative analysis based on principles of metabolism

Three cases are presented to illustrate that quantitative analysis based on physiologic principles can help resolve certain controversies in clinical medicine. For example, in case 1, a patient with severe hypoxia, the rate of production of lactic acid is so high that only restoration of delivery of oxygen is rational therapy. If the degree of hypoxia exceeds 5.6% of demand, dichloroacetate will not lessen the degree of acidosis. Further, even when delivery of oxygen is returned to normal, the rate of fall in lactate and rise in bicarbonate in plasma will be relatively slow. In case 2, a patient with diabetic ketoacidosis, our discussion stresses that the rate of production of ketoacids is not that rapid and that the degree of ketoacidosis is influenced to a major degree by decreasing the rate of oxidation of ketoacids in brain and kidneys. Case 3, a patient with severe hyperglycemia, illustrates that insulin will only promote the oxidation of glucose at a rapid rate once the levels of fatty acids and ketoacids decline to low levels. Accelerated transport of glucose by insulin is only a permissive action for the oxidation of glucose.

Comparative study of dermabrasion, phenol peel, and acetic acid peel

Six areas of the face and forehead of a 36-year-old white female presenting with a benign congenital blue nevus of the skin were treated by dermabrasion, bichloracetic acid, and the classic phenol peel. Comparative results at six months showed each of these methods to be approximately equal in the depth of penetration and in the quality of skin on healing. However, in these small test sites, dermabrasion appeared to remove pigment slightly more efficiently. Therefore, her forehead and cheeks were treated with dermabrasion and subsequently with chemical peel. An attempt was made to touch up the dermabraded areas with acetic acid. Full thickness burns occurred, which resulted in thick scarring that required many months to finally heal. We conclude that at least in the treatment of pigmented lesions, the modalities of phenol, acetic acid, and dermabrasion are approximately equal.

Vulvar reconstruction using a pedicle flap based on the superficial external pudendal artery

We present a new method for vulvar reconstruction based on recently described vasculature of the lower abdominal skin and subcutaneous tissue. The superficial external pudendal artery supplies the region encompassing the suprapubic and infraumbilical skin. Thus, a pedicled skin flap based on the superficial external pudendal artery is designed in the suprapubic area and rotated into place for vulvar reconstruction. Because of the thickness and pliability of the flap as well as the inconspicuous donor scar, we believe this method of reconstruction to be superior to skin grafts or bulkier (ie, musculo- and fasciocutaneous) tissue flaps.

Vulvovaginal human papillomavirus infections: clinical implications and management

The past 2 decades have witnessed an alarming increase in the incidence of human papillomavirus infections. Clinically evident cases represent only a small portion of the infected population, because millions of people have subclinical or latent infection. Human papillomavirus infection is recognized as a precursor to malignancy. Thus it is important to treat clinically evident infection. Treatment is complicated by the ability of the virus to establish latent infection and the lack of an effective antiviral agent. At present treatment is limited to the destruction of obvious and intraepithelial lesions.

Therapeutic effect of sodium dichloroacetate on visual and auditory hallucinations in a patient with MELAS

We report a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes who experienced visual and auditory hallucinations. His blood and cerebrospinal fluid lactate levels were remarkably elevated. Sodium dichloroacetate was administered orally at doses of 12.5 to 100 mg/kg/day. On normalization of the lactate levels, the hallucinations disappeared.

Plasmodium berghei: lactic acidosis and hypoglycaemia in a rodent model of severe malaria; effects of glucose, quinine, and dichloroacetate

Fulminant malaria infections are characterised by hypoglycaemia and potentially lethal lactic acidosis. In young adult Wistar rats (n = 26) infected with Plasmodium berghei (ANKA strain), hyperparasitaemia (greater than 50%), anaemia (PCV 19.6 +/- 5.3%; mean +/- SD) hypoglycaemia (1.04 +/- 0.74 mmol/litre), hyperlactataemia (13.2 +/- 2.20 mmol/litre), hyperpyruvicaemia (0.51 +/- 0.12 mmol/litre) and metabolic acidosis (arterial pH 6.96 +/- 0.11) developed after approximately 14 days of infection. Hypoglycaemia was associated with appropriate suppression of plasma insulin concentrations. In a second series of experiments the metabolic effects of treatment with glucose (500 mg/kg/hr), quinine (5 mg/kg bolus followed by 10 mg/kg over 1 hr) and a potent activator of pyruvate dehydrogenase, dichloroacetate (300 mg/kg) were studied over a 1-hr period. In control animals quinine had no measurable effects, but dichloroacetate significantly reduced arterial blood lactate (74%) and pyruvate (80%). In infected animals, glucose infusion attenuated the rise in lactate (38% compared with 82%; P less than 0.01) but quinine had no additional metabolic effects. Dichloroacetate further attenuated the rise in lactate (14%; P less than 0.01).

[Lactic acidosis and hyperlactatemia]

Lactic acidosis is a relatively frequent acid-base disorder in a hospital setting. It is defined by the association of an arterial pH inferior to 7.35 and an arterial lactate level superior to 5 mmol/l. Classically, 2 types of acidosis are distinguished on the basis of their mechanisms of onset: the type A, with evident clinical signs of tissue hypoperfusion and the type B, more are, without apparent hypoxia. This last category is observed in various circumstances such as diabetes, acute liver failure, poisoning and, more rarely, inborn errors of carbohydrate metabolism. Treatment aims primarily at the correction of the cause. The efficacy of sodium bicarbonate is presently debated, considering the risk to worsen hyperlactatemia and to induce hyperosmolarity or rebound alkalosis. The administration of dichloroacetate, an activator of pyruvate dehydrogenase, permits to correct partially the lactic acidosis but is not harmless especially in case of prolonged administration. Other therapeutic modalities are evoked. Arterial lactate level is a reliable prognostic index of shock, because blood values do not depend only of the oxygen debt but also of the efficacy of hepatic and renal lactate uptake. Sequential measurements are recommended.

Densitometric analysis of cytochrome oxidase in ischemic rat brain

Elevated brain lactate during incomplete ischemia is thought to contribute to the irreversibility of cell damage by interference with mitochondrial respiratory function, that should be evident in reduced cytochrome oxidase (CO) activity. In this study changes in the density of CO staining in a stroke model in the rat were assessed. Brains were analyzed subsequent to 30 min of ischemia followed by 30 min of reperfusion. The effects of postischemic treatment with sodium dichloroacetate (DCA)--a compound used to decrease lactate, were also evaluated. Examination of lateral cortex, hippocampus, and corpus striatum showed different intensities of CO in a distribution consistent with known regional variations in metabolic activity of the forebrain. Known laminar staining patterns in lateral cortex and areal patterns in the hippocampus were also confirmed. Comparable regions in ischemic forebrain were stained less densely for CO than controls. Image analysis demonstrated that the density of CO: (a) was greater in lateral cortex than hippocampus in control; (b) in ischemics was reduced by an equal degree in cortex and hippocampus; (c) lacked regional uniformity in ischemic rats; and (d) was not changed by DCA treatment in the majority of cases of ischemia. Our results suggest that lactate may not be the major determinant of 'selective vulnerability'. Despite elevated lactate levels in lateral cortex when compared to hippocampus in a previous study, the proportionate decrease in CO activity in lateral cortex and hippocampus was equal. However, there was a considerable decrease in CO activity subsequent to high brain lactate and some ischemic hemispheres appeared to respond to DCA treatment. Therefore, the role of excessive lactate in the exacerbation of 'selective vulnerability' warrants further evaluation. CO histochemistry can be used successfully to determine the distribution of pathology and the quality of fixation of ischemic forebrain. Densitometric measurements allowed comparative assessment of degrees of injury and the effects of treatment in discrete anatomical regions. This kind of analysis may allow localization of pathology within specific cellular circuits.

[Effects of dichloroacetate in the ischemic heart. Analysis of hemodynamics, myocardial energy metabolism and myocardial pH]

The effects of dichloroacetate (DCA), which is known to have a beneficial effect on lactic acidosis, were examined on myocardial acidosis during coronary occlusion in dogs. Ischemia was induced by complete ligation of the left anterior descending coronary artery (LAD) of the open-chest dog heart. DCA 100 mg/kg or 200 mg/kg was administered intravenously 10 or 60 min prior to the occlusion of LAD. DCA did not change the LAD flow, decreased heart rate, increased both systolic and diastolic blood pressures transiently. LAD occlusion significantly increased the ST segment of the epicardial ECG in the saline-treated group. DCA administered prior to the LAD occlusion caused 50% decrease of the elevation in ST segment during ischemia. Ischemia accelerated anaerobic metabolism in the myocardium; the levels of glycogen, adenosine triphosphate (ATP) and creatine phosphate (CP) decreased, and lactate increased during ischemia. Calculated energy charge potential was decreased, and [( G6P] + [F6P])/[FDP] ratio was increased by ischemia. The decreased levels of glycogen, ATP, CP in DCA-treated group were similar to those in saline-treated group during 3 min ischemia. Pretreatment of DCA reduced the accumulation of myocardial lactate by ischemia. There were no differences in variables except myocardial lactate levels between DCA 100 mg/kg and 200 mg/kg. The myocardial lactate levels were lower in both nonischemic and ischemic dogs by DCA 200 mg/kg than DCA 100 mg/kg. DCA did not change either the ATP levels or energy charge potential during both ischemia and reperfusion. LAD occlusion caused a significant decrease of myocardial pH from 7.51 to 6.83 in saline-treated group, while it produced only a small decrease in DCA-treated group from 7.56 to 7.35.(ABSTRACT TRUNCATED AT 250 WORDS)

Dichloroacetate administration in the treatment of endotoxin shock

Dichloroacetate (DCA), an activator of the pyruvate dehydrogenase complex, has been shown to reduce blood lactate levels effectively in various conditions. DCA administration has also sometimes resulted in beneficial cardiovascular effects. To assess its potential value in the routine management of septic shock, we studied the effects of DCA on a canine endotoxic shock model associated with moderate lactic acidosis. Eighteen dogs were pentobarbitone anesthetized, intubated, and mechanically ventilated. Thirty minutes after the administration of 3 mg/kg of Escherichia coli endotoxin, 10 dogs received 100 mg/kg followed by 100 mg/kg/hr of DCA, and eight dogs served as control. In all animals, fluid administration was titrated according to the left-sided filling pressures. In the DCA-treated animals, lactate levels rapidly fell from 3.1 +/- 1.2 to 1.3 +/- 0.8 mEq/liter after 30 min. The bolus of DCA was usually followed by a very transient increase in arterial pressure, but no sustained hemodynamic change was noted. Oxygen consumption (measured from the exhaled gases) was not affected. Four dogs in the DCA group and one dog in the control group survived the next morning (difference not significant). The present study confirms that DCA can effectively reduce blood lactate levels in endotoxic shock and might therefore be useful in severe lactic acidosis related to septic shock. However, the routine use of DCA in septic shock to improve hemodynamic status is not supported by the present findings.

[Sodium dichloroacetate--a substance with manifold therapeutic potential]

The therapeutic potential of sodium dichloroacetate (DCA) formerly called vitamin B 15, has already been under investigation for the past few years. The predominant property of DCA underlying its therapeutic action is activation of pyruvate dehydrogenase. The potential therapeutic use of DCA in the treatment of lactic acidosis and type II diabetes mellitus related directly to its stimulatory effect on this enzyme. Additional favourable effects of DCA on cardiac performance in states such as ischaemia, where glucose becomes a major energy-yielding substrate, have also been demonstrated. Treatment of lipid disorders might become further indications for the implementation of this substance. DCA inhibits hydroxy-methyl-glutaryl CoA reductase, thus lowering cholesterol and triglyceride levels. Earlier suggestions that DCA produced a major degree of acute toxicity were not confirmed in recent studies using DCA of established purity and homogeneity. These findings and recent evidence suggesting a potentially important role of DCA in the treatment of lactic acidosis are the reason and basis for a review of the established actions of this substance.

Comparative effects of bicarbonate and dichloroacetate in newborn swine with hypoxic lactic acidosis

Sodium bicarbonate (BC) and dichloroacetate (DCA) were studied in 7- to 14-day-old (n = 25) anesthetized swine with hypoxic acidosis. BC (base deficit X kg X 0.3, n = 10), DCA (300 mg/kg, n = 7) or saline (n = 8) was infused for 1 h. Blood lactic acid, dP/dtmax, heart rate and cardiac output increased and base excess and total arterial and carotid resistances (R) decreased with acidosis; aortic pressure, renal and mesenteric R did not change. BC induced higher pH, base excess and lactic acid. Heart rate in all and dP/dtmax with BC and DCA were restored; renal and mesenteric R and aortic pressure decreased in all. Cardiovascular responses to DCA and BC did not differ except for renal R.

CONCLUSION

BC is a more effective alkalizer than DCA, which induced a greater renal vasodilation; both restored contractility.

Reduction in spinal cord postischemic lactic acidosis and functional improvement with dichloroacetate

Pyruvate dehydrogenase complex (PDHC) is a major enzyme of glucose metabolism. Dichloroacetate (DCA) is a noncompetitive inhibitor of PDHC kinase, an enzyme that inactivates PDHC. We examined the effects of DCA on extracellular lactate and pyruvate concentration changes and spinal somatosensory evoked potentials (SSEP) in ischemic rabbit spinal cords. In the first group of 26 animals, the aorta was occluded until postsynaptic SSEP waves were completely suppressed for 10 min, a period of ischemia that causes neurologic deficits in 50% of untreated animals. DCA (25 mg/kg) was given to 13 of these animals before ischemia. In the second group of 24 animals, the aorta was occluded until the postsynaptic SSEP waves were absent for 20 min, a period of ischemia that produces paraplegia in 100% of untreated animals. DCA (25 mg/kg) was given to 16 of these animals just before the aortic occlusion was released. After occlusion, extracellular spinal lactate concentrations increased abruptly while pyruvate concentrations fell. Both lactate and pyruvate concentrations reached a plateau during the ischemic period but increased when the aortic balloon was deflated. DCA-treated animals had lower lactate and pyruvate peak concentrations during reperfusion, as well as more rapid and greater recovery of SSEP at 2 h after reperfusion. DCA did not alter spinal metabolism during the ischemia but appeared to produce a more rapid shift to glucose metabolism on reperfusion. Thus, DCA treatment resulted in better electrophysiological recovery after both moderate and severe ischemia, either by reducing lactic acidosis or by increasing the recovery rate of aerobic energy production.

[Dose dependent effects of dichloroacetate on lactic acidosis in dogs]

Dose dependent effects of DCA (dichloroacetate) on lactic acidosis were studied in 30 mongrel dogs under pentobarbital anesthesia. Lactic acidosis was induced by infusion of either lactate (n = 15) or pyruvate (n = 15) for 20 min. In each dog, saline or DCA (100 mg.kg-1 or 300 mg.kg-1) was given for ten min iv. at ten min after the beginning of lactate or pyruvate infusions. Reduction in serum pyruvate levels was more prominent than that in lactate levels in both the lactate and pyruvate infusion groups. DCA in a dose of 100 mg.kg-1 was more effective to reduce serum pyruvate levels and arterial pH than 300 mg.kg-1 of DCA. There were no differences between saline and DCA (100 mg.kg-1 or 300 mg.kg-1) administrations in mean arterial pressure and cardiac index. This study confirmed the hypothesis that DCA reduces serum lactate levels via acceleration of pyruvate metabolism. It was concluded that the ability of DCA to reduce serum lactate levels is dose-dependent and a large dose of DCA (300 mg.kg-1) would not be necessary for lactic acidosis.

Effect of sodium dichloroacetate on human pyruvate metabolism

Sodium dichloroacetate (DCA) was administered orally at doses of 12.5 to 50 mg/kg body weight twice or three times per day to a patient with mitochondrial encephalomyopathy associated with congenital lactic acidemia. During therapy, the rates of decarboxylation of (1-14C) pyruvate and (3-14C) pyruvate, which represent the activity of the pyruvate dehydrogenase (PDH) complex and the function of the TCA cycle, respectively, were markedly increased in the platelets and increases in the lactate levels in the blood and urine during exercise were markedly reduced. These results suggest that oral administration of DCA causes significant increases in the activities of the PDH complex and TCA cycle not only in the platelets but also in various tissues of humans, which is important as a pathway for production of energy, resulting in decreases in the lactate and pyruvate levels in the blood and cerebrospinal fluid.

Effects of dichloroacetate following canine asphyxial arrest

Sodium dichloroacetate (DCA) has been shown to lower elevated serum lactate levels produced by hypoxia, exercise, and phenformin. We conducted a study to investigate the effect of DCA treatment on lactic acidosis following resuscitation from asphyxial cardiac arrest. Conditioned dogs were anesthetized with pentobarbital (30 mg/kg), endotracheally intubated, and mechanically ventilated to maintain an arterial pCO2 of 30 to 40 mm Hg. Asphyxial cardiac arrest was produced by endotracheal tube occlusion for six to eight minutes. After five minutes of cardiac arrest, the endotracheal tube was unclamped and closed-chest CPR was begun. Six animals received DCA 100 mg/kg IV push after one minute of CPR. Control animals (n = 6) received an equal volume of saline. CPR was continued until the return of a spontaneous pulse, when mechanical ventilation was resumed. Arterial and venous blood gases, glucose, and lactate levels were obtained at baseline and 15, 30, 45, 60, 90, and 120 minutes after resuscitation. Mean arterial blood pressure, pulse, and glucose, and venous and arterial blood gases were similar in both groups throughout the study. By 45 minutes after resuscitation, the DCA-treated group showed a significantly faster rate of decline in lactate levels that continued to the final sampling period. By 90 minutes, arterial lactate in DCA animals was not significantly different from baseline (pre-arrest) values. DCA given during cardiac arrest will cause a more rapid normalization of arterial lactate after successful resuscitation. Further studies are needed to evaluate the effects of lowered lactic acid on survival and neurological outcome following cardiac arrest.

Comparison of sodium bicarbonate with dichloroacetate treatment of hyperlactatemia and lactic acidosis in the ischemic rat

Serum lactic acidosis is characterized by a pH less than 7.25 and lactate greater than 5 mEq. Although sodium bicarbonate (NaHCO3) is standard treatment for this condition, clinical and experimental studies suggest that high doses of NaHCO3 may be ineffectual or even detrimental to brain, cardiovascular, and respiratory function, as well as survival. For this reason, low dose therapy with NaHCO3 has been recommended. Sodium dichloroacetate (NaDCA) has been used successfully to treat clinical and experimentally-induced lactic acidosis. The present study was designed to compare the effects of low dose NaHCO3 with NaDCA on blood pressure, blood chemistries and brain metabolites in rats with a low flow-induced (Type A, the most common type) lactic acidosis. Fasted male Wistar rats were subjected to cerebral ischemia and systemic hypotension for 30 min at which time, if the pH or HCO-3 fell to 7.2 or 10, respectively, the rat was treated with NaHCO3, NaDCA, or an equal volume of sterile water. Over the 30 min of recirculation that followed ischemia, treatment had no effect on blood pressure or glucose or on brain glucose or glycogen. NaHCO3 had no effect on lactate but appeared to stabilize pH and increase HCO3- more than in sham- or NaDCA-treated rats. Although NaDCA caused a greater increase in HCO3- than sham treatment, pH continued to decline. However, lactate decreased more in NaDCA- than in sham- or NaHCO3- treated rats. These results suggest that low dose NaHCO3 is not detrimental in this model; however, although NaHCO3 stabilized pH, it did not rapidly correct the acidosis. NaDCA at this dose had no effect on the acidosis but was effective in decreasing lactate. Since serum lactate has previously correlated with survival and since higher doses of NaDCA have corrected lactic acidosis in other studies, future evaluation of postischemic treatment with higher doses of NaDCA is warranted.

Myocardial metabolic and hemodynamic effects of dichloroacetate in coronary artery disease

Dichloroacetate (DCA), which activates pyruvate dehydrogenase, has the potential to enhance carbohydrate and lactate utilization in animals, but data from patients with coronary artery disease are lacking. Accordingly, 9 patients (ages 49 to 72 years) with angina and coronary artery disease undergoing catheterization were studied. Systemic and coronary hemodynamic and metabolic measurements were made before and during DCA administration (mean dose 35 mg/kg, intravenously). DCA increased left ventricular (LV) stroke volume from 77 +/- 7 to 87 +/- 7 ml and decreased systemic vascular resistance from 1,573 +/- 199 to 1,319 +/- 180 dynes.s.cm-5 (both, p less than 0.01). There were no significant changes in heart rate, mean aortic pressure, LV end-diastolic pressure, LV dP/dt max, coronary sinus flow, coronary resistance or myocardial oxygen consumption, but myocardial efficiency index (LV work/myocardial oxygen consumption) improved from 24 to 32% (p less than 0.05). Myocardial lactate consumption was maintained (21 +/- 8 vs 19 +/- 11 X 10(-3) mEq/min, p is not significant at p less than or equal to 0.05 level) at a lower arterial lactate concentration (0.72 +/- 0.09 to 0.47 +/- 0.08 mEq/liter, p less than 0.05). DCA appears to stimulate myocardial lactate utilization at a lower arterial concentration, cause peripheral vasodilation, augment stroke volume and enhance myocardial efficiency in patients with coronary artery disease.

Dichloroacetate in the treatment of lactic acidosis

An open, prospective evaluation of the effects of dichloroacetate on morbidity and survival time was done in 29 pediatric and adult patients with lactic acidosis. Dichloroacetate was administered intravenously over 30 minutes as two 50 mg/kg body weight doses separated by 2 hours. Five patients underwent retreatment with two additional drug doses and were considered new cases when analyzing for treatment response. Survival, however, was determined from the time of initial entry into the study. Patients were considered to respond to treatment if arterial lactate concentration decreased at least 20% from the pretreatment level within 6 hours of beginning the first dichloroacetate infusion. Using this criterion, 26 cases responded to therapy with dichloroacetate. For all cases, patients' mean arterial lactate concentration decreased 52% (P = 0.0009), arterial bicarbonate concentration increased 35% (P = 0.0003), and arterial pH increased (P = 0.024) to normal, defined as the range 7.35 to 7.45. Among responders, however, arterial lactate concentration decreased 74% (P = 0.0001), arterial bicarbonate level increased 47% (P = 0.0001), and arterial pH increased (P = 0.0004) to the normal range. Median survival time among responders was 60 hours, compared to 26 hours among nonresponders (P less than 0.001). There was no evidence of toxicity to dichloroacetate.

Effects of dichloroacetate in spinal stroke in the rabbit

High levels of brain lactate may contribute to cellular death and dysfunction in acute cerebral ischemia. Although sodium dichloroacetate (DCA) has been shown to lower brain lactate in incomplete cerebral ischemia, functional outcome has not been assessed with DCA. We examined the effects of DCA treatment on functional neurologic outcome using a previously developed model for "spinal stroke" in the rabbit. Thirty male New Zealand white rabbits weighing 1.3-2.8 kg were studied. After anesthesia with 15-40 mg/kg pentobarbital IV, a laparotomy was performed and the aorta exposed. A metal clamp was placed on the aorta just distal to the left renal artery for 20 minutes and then removed. The abdominal wound was closed in two layers. Animals then received either 2cc normal saline (n = 15) or 300 mg/kg DCA in 2cc normal saline (n = 15) over 10 minutes. The animals were returned to their cages when awake and were examined at 24 hours, 48 hours, and 72 hours for neurologic assessment. The exams were performed by a blinded examiner who was unaware of the treatment given. A three point ambulatory score (0 = can't walk, 1 = walk but not hop, 2 = hopping) and a two point activity score (0 = inactive, 1 = active) were used. At 24 hours, 67% of the DCA-treated animals were actively moving about compared to only 27% of the controls (P = 0.03; Fisher Exact Test). Ten of fifteen control animals were unable to walk, while only five of fifteen DCA-treated animals were unable to walk (P = 0.07). Sixty percent of the DCA animals were able to hop compared to 27% of controls (P = 0.06). These results suggest that DCA can reduce morbidity from spinal cord ischemia in the rabbit.

Brain lactate during partial global ischemia and reperfusion: effect of pretreatment with dichloroacetate in a rat model

Elevated cerebral lactate levels following cerebral ischemia have been associated with brain cell damage and death. We previously found that pre- or postischemia treatment with dichloroacetate (DCA), presumably by its activation of brain pyruvate dehydrogenase, effectively lowers cerebral lactate levels in rats subjected to 30 minutes of partial global ischemia (PGI) followed by 30 minutes of recirculation. The goal of the present study was to determine the effects of preischemia DCA treatment on cortical lactate levels during the ischemia period or during early recirculation. Rats (four in each group) received preischemia treatment with DCA and were then subjected to 0, 10, or 30 minutes of PGI or 30 minutes of PGI followed by 15 minutes of recirculation. Cortical lactate levels in pretreated animals were not significantly different from lactate levels of untreated rats at any time during PGI, but were significantly lower than levels in untreated rats at 15 minutes of recirculation (P less than .05, ANOVA). These results suggest that preischemia treatment with DCA does not limit the accumulation of cortical lactate during PGI but may promote its clearance during recirculation following PGI. If reperfusion events influence the degree of brain cell injury, DCA may enhance cell recovery by lower cortical lactate levels in the reperfusion period.

Dichloroacetate treatment of ischemic cerebral lactic acidosis in the fed rat

Despite advances in cardiac resuscitation, ischemic brain injury remains generally untreatable. Animal studies of brain ischemia associate brain lactate levels of more than 18 mumol/g with irreversible neuronal injury. Lowering brain lactate therefore may prevent or minimize ischemic brain necrosis. Earlier studies in our laboratory using fasted rats demonstrated that sodium dichloroacetate (DCA) decreases ischemic brain lactate when given either before or immediately after partial global ischemia (PGI). Other investigators have shown that fed animals have more glucose and generate higher lactate levels by anaerobic metabolism during PGI. We evaluated the ability of DCA to lower brain lactate in fed male Wistar rats subjected to PGI. Four groups (n = 6 each) were studied--PGI and control rats with either placebo or DCA treatment. PGI was induced for 30 minutes by combining bilateral carotid artery occlusion with hemorrhagic hypotension. This was followed by release of carotid occlusion, reinfusion of shed blood, and immediate treatment with either DCA (25 mg/kg, IV) or placebo. Thirty minutes later brains were frozen in situ with liquid nitrogen for extraction and measurement of tissue glucose, glycogen, and lactate. Blood glucose and serum lactate were monitored throughout the experiment. No significant differences were found between the two PGI groups in brain glucose, brain glycogen, or ischemia-induced elevations in blood glucose and serum lactate. However, brain lactate was significantly lower in DCA-treated (12.5 mumol/g) than in untreated (22.8 mumol/g) PGI rats (P less than .001). In addition, all untreated PGI rats had levels of more than 18 mumol/g, and therefore were at high risk for neuronal necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)