ABSTRACT
BACKGROUND/AIMS: Patients severely dehydrated from diarrhea are at risk of developing hyperkalemia consequent to fluid therapy treatment. In parallel with the regulation of external potassium balance by the kidney and gastrointestinal tract, plasma potassium is rapidly regulated by redistribution of potassium between the extracellular and intracellular compartments. Erythrocytes contain ATPases that play a role in this potassium movement. In this study, erythrocyte ATPase effectiveness was evaluated in infants dehydrated from diarrhea and compared to that of healthy infants. METHODS: Blood samples were collected from dehydrated and healthy infants. The activity of Na+,K+-ATPase and of an ouabain-insensitive K+-ATPase were assessed. Serum electrolytes and blood pH were also determined. RESULTS: No hyperkalemia was found, even in dehydrated infants presenting with severe hyperchloremic metabolic acidosis. In the erythrocytes of dehydrated infants, Na+,K+-ATPase activity was increased correlating positively with the amount of sodium administered. High K+-ATPase activity in the erythrocytes correlated with low plasma potassium. The K+-ATPase activity correlated positively with the amount of potassium administered to dehydrated infants. CONCLUSION: These findings suggest that the erythrocytes Na+,K+-ATPase and K+-ATPase both protect against plasma potassium abnormalities in dehydrated infants. In such infants, the risk of hyperkalemia is probably low.
Subject(s)
Dehydration/enzymology , Diarrhea/complications , Erythrocytes/enzymology , Potassium/blood , Sodium-Potassium-Exchanging ATPase/metabolism , Acidosis/etiology , Child, Preschool , Dehydration/drug therapy , Dehydration/etiology , Female , Humans , Male , Potassium/therapeutic use , Sodium/metabolism , Sodium/therapeutic useABSTRACT
The effect of maternal hypercholesterolemia on the course of pregnancy and the development of offspring was investigated. Rats were fed either an enriched-cholesterol diet (HC) or a standard diet (control) from 1 week before mating until weaning of offspring. Compared with the control group, HC dams showed a fourfold increase in abortions, a twofold increase in neonatal mortality, smaller litter size, and lower birth weight of pups. At weaning, Na(+),K(+)-ATPase activity in the outer renal medulla was reduced in HC pups compared with control pups, suggesting retarded or impaired development of medullary nephron segments. At this point, to better examine the adverse effects of maternal hypercholesterolemia, the HC pups were divided into two groups: one fed a cholesterol-enriched diet (HC/hc) and the other a standard diet (HC/nc), while control pups were maintained on the standard diet. In adulthood, the HC/hc group showed growth impairment and reduced renal function, demonstrated by low creatinine clearance (0.24+/-0.04 ml/min per 100 g body weight) and high fractional excretion of sodium, potassium, and water ( P<0.05 vs. control). These effects were partially reversed in the HC/nc group. In this study, neither dams nor offspring developed hypertension. Thus, maternal hypercholesterolemia adversely affected pregnancy outcomes and the development of offspring by inducing abnormalities and thereby reducing renal function.
Subject(s)
Growth/physiology , Hypercholesterolemia/complications , Pregnancy Complications/blood , Animals , Blood Pressure/drug effects , Cholesterol/blood , Cholesterol, Dietary/pharmacology , Drinking/drug effects , Eating/drug effects , Embryonic and Fetal Development/physiology , Female , Glomerular Filtration Rate , Hypercholesterolemia/blood , Kidney/drug effects , Kidney/growth & development , Kidney Function Tests , Male , Organ Size/drug effects , Pregnancy , Rats , Rats, Wistar , Sodium-Potassium-Exchanging ATPase/metabolism , Weight Gain/drug effectsABSTRACT
Hormonios da glandula supra-renal tem sido apontados como reguladores da homeostase extra-renal do potassio. O presente estudo avaliou o efeito do Florinef na modulacao dos mecanismos extra-renais de adaptacao ao potassio em ratos adrenalectomizados. Observou-se que os ratos tratados com Florinef apresentaram potassio plasmatico normal, provavelmente devido a entrada deste cation na celula por aumento da atividade da Na-K-ATPase.
