Inhibitory glutamatergic neurotransmission is an elemental "building block" of the oscillatory networks within the crustacean stomatogastric ganglion (STG). This study constitutes the initial characterization of glutamatergic currents in isolated STG neurons in primary culture. Superfusion of 1 mM L-glutamate evoked a current response in 45 of 65 neurons examined. The evoked current incorporate...

Cl- efflux induces depolarization and contraction of smooth muscle cells. This study was undertaken to explore the role of Cl- channels in endothelin-1 (ET-1)-induced contraction in rabbit basilar artery. Male New Zealand White rabbits (n = 26), weighing 1.8-2.5 kg, were euthanized by an overdose of pentobarbital. The basilar arteries were removed for isometric tension recording. ET-1 produced ...

Anion conductance across the Drosophila melanogaster Malpighian (renal) tubule was investigated by a combination of physiological and transgenic techniques. Patch-clamp recordings identified clusters of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)-sensitive "maxi-chloride" channels in a small domain of the apical membrane. Fluid secretion assays demonstrated sensitivity to the chlori...

Cervical mucus thinning and release during the female reproductive cycle is thought to rely mainly on fluid secretion. However, we now find that mucus released from the murine reproductive tract critically depends upon concurrent bicarbonate (HCO(3)(-)) secretion. Prostaglandin E(2) (PGE(2))- and carbachol-stimulated mucus release was severely inhibited in the absence of serosal HCO(3)(-), HCO(...

The liverwort Conocephalum conicum with anion channels blocked by anthracene-9-carboxylic acid (A-9-C) and potassium channels blocked by tetraethylammonium (TEA) generates dose-dependent responses to illumination further called voltage transients (VTs). Unlike the action potentials in untreated Conocephalum thalli, VTs do not propagate and cannot be evoked by electrical stimuli. Except A-9-C, t...

In mammalian brain, neurons and astrocytes are reported to express various chloride and anion channels, but the evidence for functional expression of Ca(2+)-activated anion channel (CAAC) and its molecular identity have been lacking. Here we report electrophysiological evidence for the CAAC expression and its molecular identity by mouse Bestrophin 1 (mBest1) in astrocytes of the mouse brain. Us...

Haptoglobin is a putative adiposity marker because its concentration in blood is increased in obese humans. The present studies examined haptoglobin release by explants of adipose tissue in primary culture. Haptoglobin was released by explants of human visceral and subcutaneous adipose tissue at a nearly linear rate over 48 h. Explants of visceral adipose tissue released more haptoglobin than d...

Although it is known that cephalopods and other marine molluscs accumulate organic osmolytes to prevent cellular water loss in the high salinity of seawater, very few studies on molluscs, and no studies on cephalopods have been performed to characterize the underlying transport processes. We used [H] betaine to quantify the uptake of betaine into giant fiber lobe motor neurons of the squid Loll...

The first response of brown adipocytes to adrenergic stimulation is a rapid depolarizing conductance increase mediated by alpha-adrenergic receptors. We used patch recording techniques on cultured brown fat cells from neonatal rats to characterize this conductance. Measurements in perforated patch clamped cells showed that fast depolarizing responses were frequent in cells maintained in culture...

We examined the voltage-dependent block of Caactivated Cl channels by anthacene-9-carboxylic acid (A9C), diphenylamine-2-carboxylic acid (DPC), 4,4*-diisothiocyanostilbene-2,2*-disulfonic acid (DIDS), and niflumic acid (NFA) in excised inside-out and outside-out patches from Xenopus oocytes. The fraction of the voltage field (d) experienced by the blocking drug was determined from the voltage d...