Defects in myocyte contraction and relaxation are key features of human heart failure. Sodium/calcium exchanger-mediated contribution to contraction and relaxation were separated from other mechanisms [L-type calcium current, sarco(endo)plasmic reticulum (SR) Ca(2+)-ATPase] based on voltage, temperature, and selective blockers. Rod-shaped left ventricular myocytes were isolated from failed huma...

BACKGROUND Cardiac myocytes demonstrate significant swelling and associated reduced contractility in response to stress that is prevented by the ATP-sensitive potassium channel opener, diazoxide (DZX) via an unknown mechanism. One proposed mechanism of cardioprotection is mitochondrial matrix swelling. To establish the relationship between mitochondrial and cellular volume during stress, this s...

Experimental solutions known to affect mast cells or to cause liberation of histamine from the tissue were introduced into the peritoneal cavity of rats. Samples of the peritoneal fluid were withdrawn at intervals afterward and assayed for histamine and the condition of the mast cells was subsequently ascertained by microscopic examination of stained spreads of the mesenteries. Intraperitoneal ...

Abnormalities in intracellular calcium (Ca(i)(2+)) handling have been implicated as the underlying mechanism in a large number of pathologies in the heart. Study into the relation between Ca(i)(2+) behavior and performance of the whole heart function could provide detailed information into the cellular basis of heart function. In this study we describe an optical ratio imaging setup and an anal...

Thermal hyperalgesia is the heightened sensitivity to heat and occurs during inflammation. NGF-induced thermal hyperalgesia is neutrophil-dependent (Foster et al., 2003). This group previously found that the TRPV1 receptor mediates a bilateral thermal hyperalgesia in TNFα-induced inflammation (Russell et al., 2005), but it is not yet known how TNFα mediates the response. The aim of this study w...

Using a chronoamperometric technique with carbon-fiber microelectrodes and neural recordings, we simultaneously measured the effects of the following procedures on catecholamine efflux (delta CA) and frequency of chemosensory discharges (fx) from superfused cat carotid body: 1) the addition of CO2-HCO3- to Tyrode solution previously buffered with N-2-hydroxyethylpiperazine-N'-2-ethane-sulfonic ...

The influence of nicotine in modulating vulnerability to atrial tachycardia and fibrillation (AT/AF) remains ill defined. The isolated hearts of six young (2-3 mo) and six old (22-24 mo) male Fischer 344 rats were Langendorff perfused at 5 ml/min with oxygenated Tyrode solution at 37 degrees C, and the whole heart was also super-fused with warmed oxygenated Tyrode solution at 15 ml/min. Nicotin...

To investigate the suggestion that von Willebrand factor (vWf) can substitute for fibrinogen in supporting ADP-induced aggregation of human platelets, we studied platelet reactions in two media: (1) a high calcium medium, Tyrode-albumin solution containing calcium ions in the physiological range of 2 mmol/L, and (2) a low calcium medium, modified Tyrode-albumin solution from which calcium salt ...

Iturriaga, Rodrigo, and Julio Alcayaga. Effects of CO2HCO3 2 on catecholamine efflux from cat carotid body. J. Appl. Physiol. 84(1): 60–68, 1998.—Using a chronoamperometric technique with carbon-fiber microelectrodes and neural recordings, we simultaneously measured the effects of the following procedures on catecholamine efflux (DCA) and frequency of chemosensory discharges (fx) from superfuse...

onion (allium cepa) bulb from liliaceae has antioxidant, spasmolytic and antihypertensive activities. the aim of present study was to investigate the antispasmodic effect of onion peel on rat ileum contractility. onion peel powder was extracted by maceration in 70% alcohol for 72 h. a terminal portion of ileum from male wistar rat was dissected and its contractions were recorded isotonically in...