there is strong evidence demonstrating that nifedipine dissolved in ethanol selectively inhibits only l-type ca2+ current. in addition, acute ethanol exposure reduces voltage-dependent calcium currents. in the present study, we investigated the antagonistic effect of fixed concentration of nifedipine dissolved in different concentration of ethanol on l-type ca2+ current. in a na+-k+ free soluti...

Our objectives were to identify the relative contributions of [Ca2+]i and myofilament Ca2+ sensitivity in the pulmonary venous smooth muscle (PVSM) contractile response to the thromboxane A2 mimetic U-46619 and to assess the roles of PKC, tyrosine kinases (TK), and Rho-kinase (ROK) in that response. We tested the hypothesis that U-46619-induced contraction in PVSM is mediated by both increases ...

BACKGROUND Aldosteronism may account for oxi/nitrosative stress, a proinflammatory phenotype, and wasting in congestive heart failure. We hypothesized that aldosterone/1% NaCl treatment (ALDOST) in rats enhances Ca2+ and Mg2+ excretion and leads to systemic effects, including bone loss. METHODS AND RESULTS At 1, 2, 4, and 6 weeks of ALDOST, we monitored Ca2+ and Mg2+ excretion, ionized [Ca2+]...

Zhang, Xue-Qian, Jianliang Song, Lois L. Carl, Weixing Shi, Anwer Qureshi, Qiang Tian, and Joseph Y. Cheung. Effects of sprint training on contractility and [Ca2 ]i transients in adult rat myocytes. J Appl Physiol 93: 1310–1317, 2002. First published July 5, 2002; 10.1152/ japplphysiol.01071.2001.—The effects of 6–8 wk of highintensity sprint training (HIST) on rat myocyte contractility and int...

Previous studies have demonstrated that the voltage-dependent Ca2+ current recorded from the cell body of the crayfish abdominal motoneuron, F3, undergoes a long-term reduction as a result of increased impulse activity. The properties of the Ca2+ channels undergoing this long-term change were examined with the use of two-electrode voltage-clamp techniques. The Ca2+ current was activated at -50 ...

Cytosolic free calcium ([Ca2+]i) and fusion of secondary granules with the phagosomal membrane (phagosome-lysosome fusion, P-L fusion) were assessed in single adherent human neutrophils during phagocytosis of C3bi-opsonized yeast particles. Neutrophils were loaded with the fluorescent dye fura2/AM and [Ca2+]i was assessed by dual excitation microfluorimetry. Discharge of lactoferrin, a secondar...

ADP influx and ADP phosphorylation may alter mitochondrial free [Ca2+] ([Ca2+](m)) and consequently mitochondrial bioenergetics by several postulated mechanisms. We tested how [Ca2+](m) is affected by H2PO4(-) (P(i)), Mg2+, calcium uniporter activity, matrix volume changes, and the bioenergetic state. We measured [Ca2+](m), membrane potential, redox state, matrix volume, pH(m), and O2 consumpti...

The relationship between the intraluminal Ca2+ content of endoplasmic reticulum and the rate of the glucuronidation of p-nitrophenol was investigated in isolated rat hepatocytes. Different agents which decrease the Ca2+ level in the endoplasmic reticulum [calcium ionophores (A23187, ionomycin) or Ca(2+)-ATPase inhibitors(thapsigargin,2,5-di-(t-butyl)-1,4-benzohydroquinone+ ++)] inhibited the co...