The release of internal Ca from saponin-treated skinned smooth muscle of guinea pig taenia caecum was studied. The amount of Ca released was estimated by the area under the contraction curve during treatment with 25 mM caffeine in the presence of 0.1 mM EGTA. The magnitude of the caffeine response in skinned muscle, after loading with 10(-6) M Ca for 3 min, was similar to that in the depolarize...

Interactions between Cl-, SO42- and cementitious materials, reinforcement passive films influence the durability of reinforced concrete structures. Transport three solutions (NaCl, Na2SO4, mixed) in calcium silicate hydrate (C-S-H) gel, γ-FeOOH nanopores was investigated using molecular dynamics. Solution transport is slower than C-S-H gel because lesser hydrophilicity surface. can form ion clu...

The dependence of the Ca++-activated Cl- channels on potential difference (PD) was extracted from current-voltage (I/V) profiles recorded at the time of hypotonic regulation while the large conductance (G) K+ channels were blocked by tetraethylammonium (TEA). The total clamp current (I) was dominated by the Cl- I, i(Cl), with small contribution from the background I (i(background)). The i(Cl) w...

Pheromones are substances released from animals that, when detected by the vomeronasal organ of other individuals of the same species, affect their physiology and behavior. Pheromone binding to receptors on microvilli on the dendritic knobs of vomeronasal sensory neurons activates a second messenger cascade to produce an increase in intracellular Ca(2+) concentration. Here, we used whole-cell a...

The maintenance of ion homeostasis requires adequate ion sensors. In leeches, 34 nephridial nerve cells (NNCs) monitor the Cl(-) concentration of the blood. After a blood meal, the Cl(-) concentration of leech blood triples and is gradually restored to its normal value within 48 h after feeding. As previously shown in voltage-clamp experiments, the Cl(-) sensitivity of the NNCs relies on a pers...

Absorption characteristics of Mg(2+) and Cl(-) were investigated with 5-day-old excised corn (Zea mays) roots. Uptake from both 0.5 and 10 milliequivalents per liter MgCl(2) solutions occurred at steady state rates for the first 6 hours. Inhibition by dinitrophenol and low temperatures established that absorption during this period was metabolically mediated in the absence and presence of Ca(2+...

A visible spectrum of the cluster Ca2Cl3 was observed from 651 to 630 nm by 1118 resonant multiphoton ionization spectroscopy. Spectra were obtained for each of the four isotopomers: Ca2 Cl3, Ca2 Cl2 Cl, Ca2 Cl Cl2, and Ca2 Cl3. The spectra were composed of a strong origin band at 15 350.8 cm and several very weak vibronic bands. All of the bands were sharp with partially resolved rotational ba...

We examined the effects of metabolic inhibition on intracellular Ca(2+) release in single pulmonary arterial smooth muscle cells (PASMCs). Severe metabolic inhibition with cyanide (CN, 10 mM) increased intracellular calcium concentration ([Ca(2+)](i)) and activated Ca(2+)-activated Cl(-) currents [I(Cl(Ca))] in PASMCs, responses that were greatly inhibited by BAPTA-AM or caffeine. Mild metaboli...

GABA is the primary inhibitory neurotransmitter in adult mammalian brain. However, in neonatal animals activation of Cl-permeable GABA receptors is excitatory and appears to depend on the expression of a Na-K-2Cl cotransporter (NKCC) that elevates intracellular Cl levels, leading to a depolarized Cl equilibrium potential (ECl). The change from excitation to inhibition appears to involve the exp...