The ionic requirements for entry of Shiga toxin into cells were examined by measuring inhibition of protein synthesis after short-term incubations with toxin. The sensitivity of Vero cells and HeLa cells to Shiga toxin was strongly dependent on the divalent cation present. Vero cells were most sensitive in the presence of CaCl2 and SrCl2, whereas HeLa cells were equally sensitive in the presenc...

Ionic currents induced by cell swelling were characterized in primary cultures of rabbit distal bright convoluted tubule (DCTb) by the whole cell patch-clamp technique. Cl- currents were produced spontaneously by whole cell recording with an isotonic pipette solution or by exposure to a hypotonic stress. Initial Cl- currents exhibited outwardly rectifying current-voltage relationship, whereas s...

A mixture of acrylamide (AAm) and methacrylic acid (MAA) was crosslinked onto Gum ghatti (Gg) using N, N’-methylene-bis-acrylamide (MBA) as a crosslinker and ascorbic acid (ABC) and potassium persulphate (KPS) redox pair as an initiator. Optimized reaction parameters for the graft copolymerization of Gum ghatti with AAm were time (min)=90; temperature (C)=50; pH=7.0; deionized water (ml)=10; mo...

L-type Ca2+ channel currents were recorded from myocytes isolated from bovine pial and porcine coronary arteries to study the influence of changes in intracellular pH (pHi). Whole cell ICa fell when pHi was made more acidic by substituting HEPES/NaOH with CO2/bicarbonate buffer (pHo 7.4, 36 degrees C), and increased when pHi was made more alkaline by addition of 20 mM NH4Cl. Peak ICa was less p...

Some basic pharmacological differences between isolated human cerebral and digital arteries obtained at postmortem have been studied. Spiral strip responses were measured isometrically and cumulative drug dose-response curves obtained. Contractile responses were sought to norepinephrine, 5hydroxytryptamine, angiotensin, histamine, KCI, BaCl2 and prostaglandin F2o. Relaxation responses (either b...

Voltage-dependent calcium currents were measured by whole-cell recording technique in cultured cerebellar granule neurons from 8 d old rats, in 10 mM BaCl2 and with a holding potential of -80 mV. A saturating dose (10 microM) of the dihydropyridine nimodipine reversibly inhibited the maximum current by 25% and the dose dependence showed IC50 close to 50 nM. omega-Conotoxin GVIA (cgtx, 5 microM)...

Ion channels and ion fluxes control many aspects of tissue homeostasis. During oncogenic transformation, critical ion channel functions may be perturbed but conserved tumor specific ion fluxes remain to be defined. Here we used the tumoricidal protein-lipid complex HAMLET as a probe to identify ion fluxes involved in tumor cell death. We show that HAMLET activates a non-selective cation current...

OBJECTIVES Angiotensin II type 1 receptor blockers (ARBs) represent one of the widely used antihypertensive agents. In addition to anti-hypertension effect, some ARBs also show other molecular effects such as activating peroxisome proliferator-activated receptor-γ and so on. Here we studied the effects of telmisartan on the rat isolated mesenteric artery rings pre-contracted by phenylephrine (P...

The function of the apical Na+-K+-2Cl-cotransporter in mammalian choroid plexus (CP) is uncertain and controversial. To investigate cotransporter function, we developed a novel dissociated rat CP cell preparation in which single, isolated cells maintain normal polarized morphology. Immunofluorescence demonstrated that in isolated cells the Na+-K+-ATPase, Na+-K+-2Cl-cotransporter, and aquaporin ...

Concentrations of Cd, Pb and Zn in soils developed at 63 sites of historical metal mining in western Małopolska (S Poland) were estimated. Heavy metal concentrations were measured with an atomic absorption spectrometer after wet digestion in hot HClO4 (total forms), extraction in 0.1 M BaCl2 (exchangeable forms) or in water (water-soluble forms). Basic soil properties such as texture, C, N, Ca ...