Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pseudohypoaldosteronism (PHA) is a disease characterized by hyponatremia, hypotension, and dehydratation, despite the presence of hyperreninemic hyperaldosteronism. The membrane-bound Na,K ATPase activity and the transmembrane Na and K transport systems have been studied in vitro in red blood cells of two subjects, son and mother, affected by pseudohypoaldosteronism with different degrees of clinical involvement. Both parameters were significantly altered suggesting that the refractory response to mineralocorticoids is detectable, not only in kidneys and salivary and sweat glands, but also in red blood cells. Since pseudohypoaldosteronism, in its asymptomatic form, may be much more common than expected, we suggest the use of the tests described herein as a practical approach to the early diagnosis of pseudohypoaldosteronism in the investigation of sodium wasting syndromes.
 ...
PMID:Erythrocyte transmembrane Na and K fluxes in pseudohypoaldosteronism. 133 41

Pseudohypoaldosteronism is a hereditary salt-wasting syndrome usually seen in infancy with weight loss, dehydration, and failure to thrive. The pathophysiologic origin of pseudohypoaldosteronism is unknown. The defect could be related to the unresponsiveness of target organs to mineralocorticoids resulting in hyponatremia, hyperkalemia, and markedly elevated plasma aldosterone and renin levels. Red blood cell Na+, K(+)-ATPase activity was measured in a pair of twins with pseudohypoaldosteronism, in an unrelated child with hypoaldosteronism, and in an age-matched group of 50 healthy infants and young children. The enzyme was assayed by a method that couples ATP hydrolysis with NADH oxidation. Plasma renin and aldosterone levels were measured by RIA. Red blood cell Na+, K(+)-ATPase activity in the twins with pseudohypoaldosteronism was very low at the time of diagnosis (3 wk). In both twins a time-related gradual increase in enzyme activity was observed during the 1st mo of life, reaching control values between 6 and 8 mo of age. This increase was associated with both a reduction in salt requirement and clinical improvement. Plasma renin activity and aldosterone levels were very high at the time of diagnosis. Plasma renin activity reverted gradually to normal values, whereas aldosterone levels remained high throughout the follow-up period. The child with hypoaldosteronism had normal Na+, K(+)-ATPase activity at diagnosis and during follow-up.
 ...
PMID:Reduced Na+, K(+)-ATPase activity in patients with pseudohypoaldosteronism. 819 May 30

The collecting duct of the mammalian kidney is important for the regulation of extracellular volume, osmolarity, and pH. There are two major structurally and functionally distinct cell types: principal cells and intercalated cells. The former regulates Na+ and water homeostasis, while the latter participates in acid-base homeostasis. In vivo lineage tracing using Cre recombinase or its derivatives such as CreGFP and CreERT2 is a powerful new technique to identify stem/progenitor cells in their native environment and to decipher the origins of the tissue that they give rise to. Recent studies using this technique in mice have revealed multiple renal progenitor cell populations that differentiate into various nephron segments and collecting duct. In particular, emerging evidence suggests that like principal cells, most of intercalated cells originate from the progenitor cells expressing water channel Aquaporin 2. Mutations or malfunctions of the channels, pumps, and transporters expressed in the collecting duct system cause various human diseases. For example, gain-of-function mutations in ENaC cause Liddle's syndrome, while loss-of-function mutations in ENaC lead to Pseudohypoaldosteronism type 1. Mutations in either AE1 or V-ATPase B1 result in distal renal tubular acidosis. Patients with disrupted AQP2 or AVPR2 develop nephrogenic diabetes insipidus. A better understanding of the function and development of the collecting duct system may facilitate the discovery of new therapeutic strategies for treating kidney disease.
 ...
PMID:Development and Diseases of the Collecting Duct System. 2964 58