Effect of Ca2+, cyclic GMP, and cyclic AMP added to artificial solution perfusing lingual artery on frog gustatory nerve responses.

Nagahama, Setsuko; Kobatake, Yonosuke; Kurihara, Kenzo

doi:10.1085/jgp.80.5.785

Cited by 21 publications

(6 citation statements)

References 24 publications

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“…Our findings that all sugar fractions (TC1‐22‐4, TC1‐22‐5, and TC1‐25‐1) induced contractile responses in prostate preparations initially suggested that carbohydrates might be involved in contractility. Sugars such as galactose and mannose have been reported to increase intracellular Ca 2+ by inducing Ca 2+ influx in a number of cells by activating T‐type Ca 2+ channels 20, 21. However, we observed no physiological activity on the isolated rat prostate from administering glucose, sucrose, and fructose.…”

Section: Discussioncontrasting

confidence: 68%

The impact of advanced chronic kidney disease on in‐hospital mortality following percutaneous coronary intervention for acute myocardial infarction

Vasu

Gruberg

Brown

2007

Cathet Cardio Intervent

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Section: Discussioncontrasting

confidence: 68%

The impact of advanced chronic kidney disease on in‐hospital mortality following percutaneous coronary intervention for acute myocardial infarction

Vasu

Gruberg

Brown

2007

Cathet Cardio Intervent

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“…Our own studies of the process of bitter taste transduction suggest that it is mediated by a cell surface receptor, which upon binding the appropriate ligand stimulates the synthesis of an intracellular second messenger, result-ing in the release of calcium from internal stores (Akabas et al, 1988). An increasing amount of evidence is accumulating that intracellular second messengers are important in the transduction of various taste modalities (Nagahama, Kobatake & Kurihara, 1982;Hwang et al, 1989;Striem et at., 1989).…”

Section: Discussionmentioning

confidence: 99%

Identification of electrophysiologically distinct subpopulations of rat taste cells

1990

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The gustatory sensory system provides animals with a rapid chemical analysis of a potential food substance providing information necessary to facilitate ingestion or rejection of the food. The process of gustatory transduction is initiated in the taste cells in the lingual epithelium. However, due to the small size, scarcity of the cells and their location, embedded in a keratinized squamous epithelium, it has been difficult to study the primary events in the transduction process. Recently, we have developed a preparation of dissociated rat taste cells that permits studies of the taste transduction process in single isolated cells. We have now investigated the electrophysiological properties of the rat taste cells using the patch-clamp technique. We have identified two populations of cells within the taste bud: one expressing a voltage-dependent potassium current and the second containing both voltage-dependent sodium and potassium currents. The potassium current in both cell groups is blocked by external TEA, Ba2+, and quinine. Two types of K+ channels have been identified: a 90-pS delayed rectifier K+ channel and a "maxi" calcium-activated K+ channel. The sodium current is blocked by TTX, but not by amiloride.

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“…refs. 32,35,40,41,68). However, the significance of cyclic nucleotide effects remained controversial.…”

Section: Discussionmentioning

confidence: 99%

“…refs. 11,40). The effect of membrane-permeant bitter substances on the cAMP-phosphodiesterase is also controversial (e.g.…”

Section: Discussionmentioning

confidence: 99%

Patch-clamp study of isolated taste receptor cells of the frog

1987

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Taste discs were dissected from the tongue of R. ridibunda and their cells dissociated by a collagenase/low Ca/mechanical agitation protocol. The resulting cell suspension contained globular epithelial cells and, in smaller number, taste receptor cells. These were identified by staining properties and by their preserved apical process, the tip of which often remained attached to an epithelial (associated) cell. When the patch pipette contained 110 mM KCl and the cells were superfused with NaCl Ringer's during whole-cell recording, the mean zero-current potential of 22 taste receptor cells was -65.2 mV and the slope resistance 150 to 750 M omega. Pulse-depolarization from a holding voltage of -80 mV activated a transient TTX-blockable inward Na current. Activation became noticeable at -25 mV and was half-maximal at -8 mV. Steady-state inactivation was half-maximal at -67 mV and complete at -50 mV. Peak Na current averaged -0.5 nA/cell. The Ca-ionophore A23187 shifted the activation and inactivation curve to more negative voltages. Similar shifts occurred when the pipette Ca was raised. External Ni (5 mM) shifted the activation curve towards positive voltages by 10 mV. Pulse depolarization also activated outward K currents. Activation was slower than that of Na current and inactivation slower still. External TEA (7.5 mM) and 4-amino-pyridine (1 mM) did not block, but 5 mM Ba blocked the K currents. K-tail currents were seen on termination of depolarizing voltage pulses. A23187 shifted the IK(V)-curve to more negative voltages. Action potentials were recorded when passing pulses of depolarizing outward current. Of the frog gustatory stimulants, 10 mM Ca caused a reversible 5- to 10-mV depolarization in the current-clamp mode. Quinine (0.1 mM, bitter) produced a reversible depolarization accompanied by a full block of Na current and, with slower time-course, a partial block of K currents. Cyclic AMP (5 mM in the external solution or 0.5 microM in the pipette) caused reversible depolarization (to -40 to -20 mV) due to partial blockage of K currents, but only if ATP was added to the pipette solution. Similar responses were elicited by stimulating the adenylate cyclase with forskolin. Blockage of cAMP-phosphodiesterase enhanced the response to cAMP. These results suggest that cAMP may be one of the cytosolic messengers in taste receptor cells. Replacement of ATP by AMP-PNP in the pipette abolished the depolarizing response to cAMP.(ABSTRACT TRUNCATED AT 400 WORDS)

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Effect of Ca2+, cyclic GMP, and cyclic AMP added to artificial solution perfusing lingual artery on frog gustatory nerve responses.

Cited by 21 publications

References 24 publications

The impact of advanced chronic kidney disease on in‐hospital mortality following percutaneous coronary intervention for acute myocardial infarction

The impact of advanced chronic kidney disease on in‐hospital mortality following percutaneous coronary intervention for acute myocardial infarction

Identification of electrophysiologically distinct subpopulations of rat taste cells

Patch-clamp study of isolated taste receptor cells of the frog

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