The ability to maintain cellular volume is an important general physiological function. Swelling induced by hypotonic stress results in the opening of channels, through which ions exit with accompanying water loss (regulatory volume decrease, RVD). RVD has been shown to occur in mammalian sperm, primarily through the opening of quinine-sensitive potassium channels. However, as yet, direct evide...

We have previously shown that monoclonal antibody E12 (MAb E12), one of several such antibodies raised against theophylline-treated Necturus gallbladder (NGB) epithelial cells, inhibits the chloride conductance in the apical membrane of that tissue. Since chloride channels are critical to the secretory function of epithelia in many different animals, we have used this antibody to determine whet...

In mature mammalian muscle, the chloride conductance of the membrane is an important factor in the regulation of excitability. Up to now, no ligand was available for the biochemical characterization of muscle chloride channels. In order to localize and characterize these channels, we have used indanyloxyacetic acid (IAA)-94, a ligand previously used for epithelial Cl- channels (Landry, D. W., R...

Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm l-1 when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility from patients with asthenozoospermia. Spermatozoa were purified using Percoll density gradients. Sperm volume was measured as the forward scatter signal using flow cytometry. Sperm ...

CLC-2 is a hyperpolarization-activated, inwardly rectifying chloride channel. Although the properties of the CLC-2 channel have been well characterized, its function in vivo is not well understood. We have found that channels encoded by the Caenorhabditis elegans CLC-2 homolog clh-3 regulate the activity of the spontaneously active hermaphrodite-specific neurons (HSNs), which control the egg-la...

Enhanced airway smooth muscle (ASM) contraction is an important component in the pathophysiology of asthma. We have shown that ligand gated chloride channels modulate ASM contractile tone during the maintenance phase of an induced contraction, however the role of chloride flux in depolarization-induced contraction remains incompletely understood. To better understand the role of chloride flux u...

The transient receptor potential (TRP) channel superfamily includes a large number of proteins that constitute 7 subfamilies (TRPC, TRPV, TRPM, TRPML, TRPN, TRPA and TRPP). These channels have been strongly conserved evolutionarily. The family was first cloned from a mutant Drosophila strain in which receptor potentials in the eye were transient upon light stimulation. There are 27 known channe...

The circadian pattern of aqueous formation and the effect of timolol on aqueous flow was studied in 12 patients with cystic fibrosis. Cystic fibrosis is a disease characterized by a defect in a chloride channel-associated regulatory protein found in epithelial cells. Improper regulation of these chloride channels, causes abnormal composition of exocrine secretions, including respiratory tract, ...

Basolateral membrane chloride permeability of surface cells from rabbit urinary bladder epithelium was studied using the patch-clamp technique. Two types of anion-selective channel were observed. One channel type showed inward rectification and had a conductance of 64 pS at-50 mV when bathed symmetrically by saline solution containing 150 mM chloride; the other resembled high-conductance voltag...