Lactate blood concentration

PDH deficiency results in raised blood concentrations of pyruvate, lactate and alanine. Some patients respond to supplementation with lipoic acid or thiamin (coenzymes for PDH). Treatment with a low carbohydrate, ketogenic diet has been advocated but with limited success. (The ketone bodies readily cross the blood-brain barrier and their catabolism produces acetyl CoA independently of PDH.)... 

The lactate produced mainly in muscle diffuses in blood and reaches the heart where the principal function of LDH-H is oxidizing lactate to pyruvate, which can then be utilized through the Krebs cycle. In fact, if blood concentrations of lactate are increased, the uptake of that metabolite by the heart is also increased. Thus, the H-type is the true lactic dehydrogenase, while the M-type is really a pyruvic reductase. 

The decarboxylation and oxidation of pyruvate to form acetyl CoA requires the coenzyme thiamin diphosphate, which is formed from vitamin (section 11.6.2). In thiamin deficiency, this reaction is impaired, and deficient subjects are unable to metabolize glucose normally. Especially after a test dose of glucose or moderate exercise they develop high blood concentrations of pyruvate and lactate. In some cases this may be severe enough to result in life-threatening acidosis. 

The present study demonstrated that urea transport across gut epithelia is directly proportional to the blood concentration of urea in lactating dairy cows i.e. in the short term the extraction ratio upon passage of the epithelial bed is unaffected by increased blood urea concentration. The epithelial permeability for urea was markedly affected by the ration offered and the extraction ratio of urea was up-regulated with LOW-N at the level of the rumen and the whole PDV. However, the relative increase in extraction was greatest for the rumen. The data obtained in the present study implies that the curvilinear relationship observed between blood urea concentration and PDV urea extraction in lactating dairy cows is caused by adaptation of the epithelial urea transport to the nutritional state of the cow and not an artifact of a transport system for urea running at a constant rate (i.e. not zero-order regulation). 

Anselme, F., Collomp, K., Mercier, B., Ahmaidi, S., and Prefaut, C., Caffeine increases maximal anaerobic power and blood lactate concentration, European Journal of Applied Physiology, 65, 188, 1992. 

In a subsequent study Bhambhani et al. (1997) observed significant increases in blood lactate concentrations in male and female volunteers exposed to 10 ppm hydrogen sulfide, although there was not a significant change in the activities of muscle lactate dehydrogenase, citrate synthase, or cytochrome oxidase. 

Delays in the development of the righting reflex were observed by Reiter et al. (1975) in rat pups whose dams were exposed to lead acetate at concentrations of 0.7 and 7 mg lead/kg/day in their drinking water throughout gestation and lactation. Eye opening was delayed at the higher exposure level. Blood lead levels were not determined. 

Uremia results in increased permeability of the blood-brain barrier to sucrose and insulin K+ transport is enhanced whereas Na+ transport is impaired. There is an increase in brain osmolarity in acute renal failure due to the increase in urea concentrations. However, in contrast to acute renal failure, the increase in osmolarity in chronic renal failure results from the presence of idiogenic osmoles in addition to urea. CBF is increased in uremic patients but CMR02 and CMR are decreased. In the brains of rats with acute renal failure, ATP, phosphocreatine and glucose are increased whereas AMP, ADP and lactate are decreased, most probably as a result of decreased energy demands. 

Most patients with pyruvate-carboxylase deficiency present with failure to thrive, developmental delay, recurrent seizures and metabolic acidosis. Lactate, pyruvate, alanine, [3-hydroxybutyrate and acetoacetate concentrations are elevated in blood and urine. Hypoglycemia is not a consistent finding despite the fact that pyruvate carboxylase is the first rate-limiting step in gluconeogenesis. 

Mozambique tilapia, Oreochromis niloticus 330 pg/L for 240 h lymphocytes and blood plasma lactate levels most blood chemistry variables were normal Whole body concentration of 14.9 mg Pb/kg FW 31... 

Cardiac index and blood pressure must be sufficient to ensure adequate organ perfusion, as assessed by alert mental status, creatinine clearance sufficient to prevent metabolic azotemic complications, hepatic function adequate to maintain synthetic and excretory functions, a stable heart rate and rhythm, absence of ongoing myocardial ischemia or infarction, skeletal muscle and skin blood flow sufficient to prevent ischemic injury, and normal arterial pH (7.34 to 7.47) with a normal serum lactate concentration. These goals are most often achieved with a cardiac index greater than 2.2 L/min/m2, a mean arterial blood pressure greater than 60 mm Hg, and PAOP of 25 mm Hg or greater. 

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