Erik Hviid Larsen

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1. The inward facing membranes of in vitro frog skin epithelium were depolarized with solutions of high K concentration. The electrical properties of the epithelium are then expected to be governed by the outward facing, Na-selective membrane.2. In this state, the transepithelial voltage (V) was clamped to zero and step-changes of Na activity in the outer(More)
Members of the TMEM16 (Anoctamin) family of membrane proteins have been shown to be essential constituents of the Ca(2+)-activated Cl(-) channel (CaCC) in many cell types. In this study, we have investigated the electrophysiological properties of mouse TMEM16F. Heterologous expression of TMEM16F in HEK293 cells resulted in plasma membrane localization and(More)
Isolated small intestine of toad (Bufo bufo) was mounted on glass tubes for perfusion studies with oxygenated amphibian Ringer's solution containing glucose and acetate. Under open-circuit conditions (V t =−3.9 ± 1.8 mV, N= 14) the preparation generated a net influx of 134Cs+. The time course of unidirectional 134Cs+-fluxes was mono-exponential with similar(More)
The voltage dependecies of Na and Cl fluxes were investigated in the isolated toad skin. With Cl-Ringer's on both sides Cl outflux varied very little with clamping voltage. The same was true for the influx of Cl at depolarizing voltages (psii -psio lessthan0 mV), wheras hyperpolarization led to a marked increase in this flux. A net chloride influx under(More)
1. Active Cl- currents were studied in short-circuited toad skin epithelium in which the passive voltage-activated Cl- current is zero. Under visual control double-barrelled microelectrodes were used for impaling principal cells from the serosal side, or for measuring the pH profile in the solution bathing the apical border. 2. The net inward (active) 36Cl-(More)
The isolated epithelium of toad skin was disintegrated into single cells by treatment with collagenase and trypsine. Chloride channels of cell-attached and excised inside-out apical membrane-patches of mitochondria-rich cells were studied by the patch-clamp technique. The major population of Cl- channels constituted small 7-pS linear channels in symmetrical(More)
1. The control by intracellular cyclic AMP and beta-adrenergic stimulation of chloride conductance was studied in toad skin epithelium mounted in a chamber on the stage of an upright microscope. Impalement of identified principal cells from the serosal side with single-barrelled conventional or double-barrelled Cl(-)-sensitive microelectrodes was performed(More)
We have hypothesized that a major role of the apical H(+)-pump in mitochondria-rich (MR) cells of amphibian skin is to energize active uptake of Cl- via an apical Cl-/HCO3(-)-exchanger. The activity of the H+ pump was studied by monitoring mucosal [H+]-profiles with a pH-sensitive microelectrode. With gluconate as mucosal anion, pH adjacent to the cornified(More)
This study deals primarily with the morphology and ultrastructure of the pronephros in the green toad Bufo viridis during prometamorphosis when the pronephros and the developing mesonephros function simultaneously. Furthermore, the mesonephros was studied during pro- and postmetamorphosis with emphasis on the distal segments of the nephron. The paired(More)