In epilepsy, the GABA and glutamate balance may be disrupted and a transient decrease in extracellular calcium occurs before and during a seizure. Flow Cytometry based fluorescence activated particle sorting experiments quantified synaptosomes from human neocortical tissue, from both epileptic and nonepileptic patients (27.7% vs. 36.9% GABAergic synaptosomes, respectively). Transporter-mediated...

Fluorescent indicators were used to detect stimulus-evoked changes in presynaptic levels of intracellular sodium (Na1) and calcium (Ca1) in granule cell parallel fibers in brain slices from rat cerebellum. Ca, increased during stimulation, and three exponentials were needed to approximate its return to prestimulus levels. Ca, decayed to -10% of peak levels with T 100 ms, to -1% of peak values w...

Intracellular sodium, potassium, and free calcium concentrations were investigated in lymphocytes of 30 patients with essential hypertension and 30 normotensive controls. All subjects were placed on a diet containing 8 to 10 g of sodium chloride per day. Lymphocyte sodium concentration was higher in hypertensive patients than in normotensive controls (19.8 +/- 1.8 vs 18.4 +/- 1.8 mmol/kg wet we...

We have measured the effects of changing tonicity of the bathing solution on intracellular sodium and calcium activities and tension of sheep cardiac Purkinje strands and ventricular muscle. For Purkinje strands in solutions of normal tonicity, resting membrane potential was -77.4 +/- 0.4 mV (mean +/- SE), sodium activity was 7.9 +/- 0.4 mM, and calcium activity was 98 +/- 9 nM. For ventricular...

AGUS, ZALMAN S., LAURENCE B. GARDNER, LAURENCE H. BECK, AND MARTIN GOLDBERG. Efects of parathyroid hormone on renal tubular reabsorption of calcium, sodium, and phosphate. Am. J. Physiol. 224(5) : 1143-l 148. 1973.-In order to study the relationships between sodium, calcium, and phosphate reabsorption in the proximal tubule and the effects of parathyroid hormone (PTH) on these relationships, re...

Disorders of calcium and parathyroid hormone homeostasis have been reported in subjects with essential hypertension. In many of these studies, dietary intakes of sodium and calcium were not carefully controlled. The present study was designed to compare calcium and parathyroid hormone homeostasis in normal and hypertensive subjects on controlled dietary sodium and calcium intakes and to examine...

We investigated the roles of sodium-calcium exchange, sarcoplasmic reticulum, and mitochondria in Cai homeostasis in cultured chick ventricular cells. Specifically, the influence of low sodium medium on contractile state, calcium fluxes, and cytosolic free [Ca] [( Ca]i) was examined. [Ca]i was measured using fura-2. Mean [Ca]i in control medium was 126 +/- 14 nM. Exposure of cells to sodium-fre...

We studied the effects of intrarenal calcium infusion on renin secretion in sodium-depleted dogs in an attempt to elucidate the major site of calcium-induced inhibition of renin release. Both calcium chloride and calcium gluconate reduced renal blood flow and renin secretion while renal perfusion pressure was unchanged. These data indicate that calcium inhibition of renin secretion did not occu...

AGUS, ZALMAN S., LAURENCE B. GARDNER, LAURENCE H. BECK, AND MARTIN GOLDBERG. Efects of parathyroid hormone on renal tubular reabsorption of calcium, sodium, and phosphate. Am. J. Physiol. 224(5) : 1143-l 148. 1973.-In order to study the relationships between sodium, calcium, and phosphate reabsorption in the proximal tubule and the effects of parathyroid hormone (PTH) on these relationships, re...

We have shown previously that burn trauma produces significant cardiac dysfunction, which is first evident 8 h postburn and is maximal 24 h postburn. Because calcium handling by the cardiomyocyte is essential for cardiac function, one mechanism by which burn injury may cause cardiac abnormalities is via calcium dyshomeostasis. We hypothesized that major burn injury alters cardiomyocyte calcium ...