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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Single rat epididymal cell studied under whole cell patch-clamp condition responded to 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (CPT-cAMP) (500 microM) and to ionomycin (1 microM) by an increase in whole cell conductance. A major part of the stimulated current was carried by Cl-, although a small part was due to nonselective cation current. After elimination of the cation current component by using impermeant cation, the cells revealed different Cl- conductance properties in response to adenosine 3',5'-cyclic monophosphate (cAMP) and ionomycin. The cAMP-stimulated Cl- conductance was independent of time and voltage and showed a linear current-voltage relationship. The anion permselectivity was NO3- > Br- > Cl- approximately I- >> SO(4)2-. The ionomycin-stimulated Cl- conductance showed marked time and voltage dependency. In contrast to the cAMP-induced anion permselectivity, the ionomycin-induced anion permselectivity was I- > Br- approximately NO3- > Cl- >> SO(4)2-. These results indicate that the epididymal epithelial cells exhibit different Cl- conductances sensitive to cAMP and Ca2+. The cAMP-activated conductance has properties resembling the type associated with the cystic fibrosis transmembrane conductance regulator found in cystic fibrosis-affected epithelia. This finding supports the notion that the epididymis is a cystic fibrosis epithelium.
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PMID:Properties of cAMP-dependent and Ca(2+)-dependent whole cell Cl- conductances in rat epididymal cells. 768 72

Swelling-induced Cl- conductance in cultured rat epididymal cells was characterized using whole cell patch-clamp techniques. Activation of whole cell current with an outwardly rectifying current-potential relationship was observed in cells exposed to hyposmotic solutions. This current was determined, from the observed current-reversal potentials at different Cl- concentrations, to be Cl- selective. The anion selectivity sequence of the swelling-induced Cl- conductance was I- approximately NO3- approximately Br- > Cl- > 2-(N-morpholino)ethanesulfonic acid. The swelling-induced Cl- conductance was reversibly inhibited by different Cl- channel blockers. Unlike diphenylamine-2-carboxylate or 5-nitro-2-(3-phenylpropylamino)-benzoate, which showed voltage-independent blockade, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid showed a marked voltage-dependent blockade of the volume-sensitive Cl- current, with a greater effect at depolarizing voltages. The swelling-induced Cl- conductance appeared to be different from the Ca(2+)- or adenosine 3',5'-cyclic monophosphate-activated Cl- conductances on the basis of the following observations: 1) swelling-induced current activation was seen even in the presence of kinase inhibitor (H-8) or absence of external free Ca2+, and 2) further increase in current activation could be produced by swelling after Ca(2+)- or adenosine 3',5'-cyclic monophosphate-induced current activation. The swelling-induced Cl- conductance may be involved in regulating epithelial cell volume as well as serving other important epididymal functions such as facilitating transepithelial secretion of organic compounds.
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PMID:Characterization of a swelling-induced chloride conductance in cultured rat epididymal cells. 769 76

1. Isolated cells from primary cultures of rat epididymal epithelial cells were employed for the study of adrenaline-stimulated Cl- transport using a Cl-(-)sensitive fluorophore 6-methoxy-N-(3-sulphopropyl) quinolinium (SPQ). SPQ was loaded into the cells by the hypotonic shock method. 2. The resting intracellular Cl- concentration, estimated in the presence of nigericin and tributyltin in high-K+ solution, was 62.3 +/- 0.2 mM. This value was not altered in the presence of 1 microM adrenaline. When extracellular Cl- was replaced by NO3-, an increase in fluorescence corresponding to a decrease in intracellular Cl- was observed. The initial outward Cl- movement was estimated to be 0.54 +/- 0.08 mM s-1. This value was increased by incubating the cells with adrenaline. The stimulatory effect of adrenaline was reduced by 1 mM DPC. 3. Addition of Cl- to cells previously depleted of Cl- caused an instantaneous decrease in fluorescence due to the entry of Cl-. The initial rate of Cl- entry was -0.62 +/- 0.13 mM s-1. Adrenaline increased the rate of entry to -2.13 +/- 0.08 mM s-1. The adrenaline-stimulated rate of entry was reduced by DPC or frusemide (0.5 mM) and was completely blocked in the presence of both agents. 4. In Na(+)-free solution, the adrenaline-stimulated rise of rate of Cl- entry was reduced in the presence of DPC. Frusemide had no effect on the entry rate. 5. The stimulatory effect of adrenaline were abolished by propranolol (5 microM) but not by phentolamine (5 microM). Conversely, isoprenaline (1 microM) and forskolin (1 microM) mimicked the effects of adrenaline.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Adrenaline-regulated Cl- transport in cultured single rat epididymal cells measured by an entrapped Cl-(-)sensitive fluorophore. 800 8