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BACKGROUND Although prolactin affects sodium and water transport across the plasma membrane and interacts with dopamine in the brain, its role in the kidney is unclear. Here we examined the effect of prolactin and its possible interaction with the intrarenal natriuretic hormone dopamine, on proximal tubular Na(+), K(+)-ATPase activity in vitro and renal(More)
The enzyme catechol-O-methyltransferase (COMT), which plays an important role for dopamine metabolism, is abundantly expressed in the kidney. To test whether the natriuretic effects of dopamine may be related to the rate of dopamine metabolism, rats were treated with nitecapone, a peripheral inhibitor of COMT. Nitecapone, given by gavage, induced a highly(More)
The capacity to concentrate urine develops progressively during postnatal life in most mammalian species. Here we have examined whether low expression of the arginine vasopressin (AVP)-activated water channel aquaporin-2 (AQP-2) may be a limiting factor for the concentrating capacity in the infant rats. Urine osmolality in response to 24-h dehydration(More)
Prolactin is a natriuretic hormone and acts by inhibiting the activity of renal tubular Na(+)-K(+)-ATPase activity. These effects require an intact renal dopamine system. Here, we have studied by which mechanism prolactin and dopamine interact in Sprague-Dawley rat renal tissue. Na(+)-K(+)-ATPase activity was measured as ouabain-sensitive ATP hydrolysis in(More)
Recent reports have shown that low birth weight infants have a higher incidence of adult hypertension. These observations have stimulated a number of studies designed to evaluate the mechanisms of this phenomenon. In this study, fetal growth retardation was induced by treating pregnant rats with dexamethasone. After birth, pups whose mothers were treated(More)
Catecholamines have pronounced effects on the renal handling of sodium and water, dopamine-promoting sodium and water excretion, and norepinephrine-promoting sodium and water retention. In the present study, using isolated permeabilized renal tubule cells and intact rats, we have shown that these effects can be attributed to opposing actions of these(More)
BACKGROUND Pulmonary hypoplasia and persistent pulmonary hypertension are the main causes of mortality and morbidity in newborns with congenital diaphragmatic hernia (CDH). Nitrofen is well known to induce CDH and lung hypoplasia in a rat model, but the mechanism remains unknown. To increase the understanding of the underlying pathogenesis of CDH, we(More)
The coupling between the Na+/glucose cotransporter and Na(+)-K(+)-ATPase (NKA) described for epithelial cells (1) prompted us to study in rats with streptozocin-induced diabetes the effect of increased tubular glucose load on tubular Na+ reabsorption, NKA-dependent O2 consumption (QO2), and NKA activity. Filtered glucose is mainly reabsorbed in the proximal(More)
BACKGROUND Levels of advanced glycation end products (AGE) are elevated in individuals with advancing age, renal failure, and diabetes, and accumulation of these molecules may contribute to disease progression. The mechanism by which AGE proteins alter glomerular mesangial cell function, however, is not completely understood. The present study assessed the(More)
The kidney is extraordinarily sensitive to adverse fetal programming. Malnutrition, the most common form of developmental challenge, retards the formation of functional units, the nephrons. The resulting low nephron endowment increases susceptibility to renal injury and disease. Using explanted rat embryonic kidneys, we found that ouabain, the Na,K-ATPase(More)