Decreased sodium-potassium and calcium adenosine triphosphatase activity in asthma: modulation by inhaled and oral corticosteroids.

The activation of both the inflammation-producing cells and the airway smooth muscle in asthma is believed to be a phenomenon dependent on the intracellular calcium. The activity of Na+ K+ ATPase and Ca2+ ATPase, enzymes responsible for regulating the intracellular calcium concentrations has been reported to be decreased in asthma. An increase in plasma lysophosphatidylcholine (LPC), which is known to be a pro-inflammatory compound and has an inhibitory effect on the two ATPases has also been reported. Corticosteroids are potent antiinflammatory drugs very effective in the treatment of asthma. The effect of long-term (12 weeks) treatment with inhaled beclomethasone dipropionate (BDP) and short-term (1 week) treatment with oral prednisolone on the activity of the two ATPases and intracellular calcium in leukocytes and plasma LPC levels was investigated. Both the treatments resulted in an improvement in lung function accompanied by an increase in the activities of the ATPases and a decrease in the intracellular calcium and LPC levels. It was concluded that increase in the activities of Na+ K+ ATPase and Ca2+ ATPase and a consequent lowering of intracellular calcium, and a lowering of plasma LPC may underlie the beneficial effect of corticosteroids in asthma.

Importance of monitoring calcium & calcium related properties in carrier detection for Duchenne muscular dystrophy.

Calcium and calcium dependent enzymes viz., calcium ATPase, protein kinase C and calcium activated neutral protease (milli CANP mCANP) were studied in the erythrocytes, platelets and lymphocytes of obligate carriers, in order to assess the usefulness of these indices for detection of carriers for Duchenne muscular dystrophy (DMD). With the exception of mCANP and lymphocyte calcium ATPase, other calcium dependent enzyme activities showed considerable overlap between carriers and control. Since the increase in the level of platelet mCANP was found in all affected boys (no false negatives) and obligate carriers, and patients with other myopathic conditions and some neurogenic causes did not show high platelet mCANP activity, this parameter could be considered as a good phenotypic index. Unlike SCK, the platelet mCANP of carriers did not overlap that of controls, hence tests are to be carried out to verify its usefulness as an index of carrier state in mutations other than DNA deletion since testing of non-deletion is both costly and has practical limitations.

Alteraciones en la actividad del calcio-magnesio ATPasa en la membrana de los eritrocitos en pacientes litiasicos con hipercalciuria / Alterations in the calcium-magnesium activity ATPase in the membrane of the erytrosites in lithiasic patients with hypercalciuria

La CaMgATPasa es una enzima involucrada en los movimientos de calcio a través de las membranas biológicas. Nosotros testeamos la actividad de dicha enzima en membranas de eritrocitos de 17 pacientes hipercalciúricos y la comparamos con 8 controles sanos. Los pacientes con hipercalciuria tuvieron una actividad de CaMgATPasa que fue significativamente superior a los controles (18,02 2,83 vs 14,69 1,78 nM . mg-1 p<0,01). La excreción de urinaria de calcio en 24 hs (UCa.V) estuvo directa y significativamente relacionada con la actividad de la enzima (UCa.V: 36,31 x CaMgATPasa - 371,08 r:0,65 p<0,05) sólo en pacientes con hipercalciuria. Cuando agrupamos los pacientes acorde al diagnóstico fisiopatológico en hipercalciuria absortiva (HCA) e hipercalciuria renal (HCRT) encontramos que la actividad enzimática estuvo sólo significativamente elevada en aquellos portadores de HCA al compararlos con los controles (19,17 3,49 vs 14,68 1,79 nM . mg-1 .min-1 p<0,025).No encontramos diferencias estadísticamente significativas entre HCRT y controles (16,83 1,99nM . mg-1 . min-1; p:NS) y en HCRT vs HCA (p<0,14). Concluimos que las alteraciones en el transporte de calcio en la hipercalciuria dependería de anormalidades en la actividad de la CaMgATPasa