scholarly journals Patch-Clamp Recording of K+ Current from Lacrimal Gland Duct Cells

2019 ◽  
Author(s):  
Loren D. Haarsma ◽  
John L. Ubels
Keyword(s):  
Patch Clamp ◽  
Lacrimal Gland ◽  
Acinar Cells ◽  
Sprague Dawley ◽  
Patch Clamp Recording ◽  
Pipette Solution ◽  
Relative Paucity ◽  
Duct Cells ◽  
Gland Duct ◽  
Electrophysiologic Studies

AbstractElectrophysiologic studies have characterized ion channels in lacrimal gland acinar cells, but due to relative paucity and inaccessibility, such studies on lacrimal gland duct cells are challenging. The duct cells are believed to secrete the high level of K+ that is present in tears. The goal of this project was to develop a method for isolation of viable, single duct cells, demonstrate their utility for patch-clamp recording and characterize the K+ channels expressed by duct cells. Exorbital lacrimal gland slices from Sprague-Dawley rats were incubated with collagenase. Under a microscope, the ducts were microdissected from the glands and then incubated with elastase and collagenase. Dispersed duct cells were plated on a cover slip coated with BD Cell-Tak. Duct cells were distinguished from acinar cells by their smaller size and lack of granularity. Whole-cell K+ currents were recorded from duct cells using the perforated-patch technique and pipettes with resistances of less than 10 MΩ. EGTA and CaCl2 in the pipette solution were adjusted to give 1 uM free Ca++. When held at −80 mV, duct cells showed K+ currents that activated at command voltages near 0 mV and reached amplitudes near 1 nA at +100 mV. Currents reached peak amplitude less than 20 ms after depolarization and did not inactivate. These currents were inactivated by holding the cells at 0 mV. Currents were blocked reversibly by TEA in the presence of Ca2+, but were not blocked by TEA in the absence of Ca2+. Currents were not affected by clotrimazole (10 uM) or Ba2+ (5 mM). A method has been established for isolation and dissociation lacrimal gland duct cells for electrophysiologic studies. These cells express a voltage-activated K+ channel that is dependent on the presence of intracellular Ca2+ and may correspond to the IKCa1 channel expressed on the apical membranes of lacrimal gland ducts.

Analysis of Gene Expression in Rat Lacrimal Gland Duct Cells using Laser Capture Microdissection and cDNA Microarrays

2005 ◽  
Vol 3 ◽  
pp. S123
Author(s):  
John L. Ubels ◽  
Holly M. Hoffman ◽  
Sujata Srikanth ◽  
James H. Resau ◽  
Craig P. Webb
Keyword(s):  
Gene Expression ◽  
Lacrimal Gland ◽  
Laser Capture Microdissection ◽  
Cdna Microarrays ◽  
Duct Cells ◽  
Gland Duct ◽  
Laser Capture

scholarly journals The anesthetic bupivacaine induces cardiotoxicity by targeting L-type voltage-dependent calcium channels

2020 ◽  
Vol 48 (8) ◽  
pp. 030006052094261
Author(s):  
YaNan Gao ◽  
Bo Chen ◽  
Xue Zhang ◽  
Rui Yang ◽  
QingLi Hua ◽  
...  
Keyword(s):  
Patch Clamp ◽  
Action Potential ◽  
Neonatal Rat ◽  
Sprague Dawley ◽  
Patch Clamp Recording ◽  
Drug Induced ◽  
Multifunctional Protein ◽  
Ventricular Cells ◽  
Sprague Dawley Rats ◽  
Voltage Dependent

Objective Bupivacaine is an amide local anesthetic with possible side effects that include an irregular heart rate. However, the mechanism of bupivacaine-induced cardiotoxicity has not been fully elucidated, thus we aimed to examine this mechanism. Methods We performed electrocardiogram recordings to detect action potential waveforms in Sprague Dawley rats after application of bupivacaine, while calcium (Ca2+) currents in neonatal rat ventricular cells were examined by patch clamp recording. Western blot and quantitative real-time polymerase chain reaction assays were used to detect the expression levels of targets of interest. Results In the present study, after application of bupivacaine, abnormal action potential waveforms were detected in Sprague Dawley rats by electrocardiogram recordings, while decreased Ca2+ currents were confirmed in neonatal rat ventricular cells by patch clamp recording. These alterations may be attributed to a deficiency of CaV1.3 (L-type) Ca2+ channels, which may be regulated by the multifunctional protein calreticulin. Conclusions The present study identifies a possible role of the calreticulin–CaV1.3 axis in bupivacaine-induced abnormal action potentials and Ca2+ currents, which may lead to a better understanding anesthetic drug-induced cardiotoxicity.

Perforated patch-clamp recording in cardiac myocytes using cation-selective ionophore gramicidin

1996 ◽  
Vol 271 (2) ◽  
pp. C524-C532 ◽  
Author(s):  
Y. Tajima ◽  
K. Ono ◽  
N. Akaike
Keyword(s):  
Patch Clamp ◽  
Reversal Potential ◽  
Ionic Currents ◽  
Patch Clamp Recording ◽  
Ionic Selectivity ◽  
Patch Clamp Technique ◽  
Pipette Solution ◽  
Electrophysiological Properties ◽  
Perforated Patch ◽  
Ventricular Cells

Whole cell currents were recorded in single myocytes dissociated from guinea pig ventricles by the patch-clamp technique. The addition of 0.1 mg/ml gramicidin D, a cation-selective ionophore, into the pipette solution induced a gradual spontaneous perforation of the patch membrane under a conventional cell-attached configuration. The access resistance, measured at approximately 12 min after formation of a gigaohm seal, was 9.2 +/- 1.5 M omega (n = 12). The perforated patch membrane exhibited ionic selectivity for various monovalent cations, with a relative order of Cs+ (1.11) > K+ (1.0) > Na+ (0.65) >> tris(hydroxymethyl)aminomethane+ (approximately 0) but was not permeable for Cl-. Under the gramicidin-perforated patch recording configuration, the cells showed the typical electrophysiological properties for ventricular cells reported previously. The intracellular Cl- concentration, estimated from the reversal potential of the catecholamine-induced Cl- current, was 36.3 +/- 2.9 mM (n = 17). We thus conclude that the gramicidin-perforated patch recording mode provides a useful tool for recording the ionic currents while maintaining the intracellular Cl- concentration.

scholarly journals Characterization of Na+-K+-2Cl−Cotransporter Activity in Rabbit Lacrimal Gland Duct Cells

2016 ◽  
Vol 57 (8) ◽  
pp. 3828 ◽  
Author(s):  
Eszter Vizvári ◽  
Máté Katona ◽  
Péter Orvos ◽  
Orsolya Berczeli ◽  
Andrea Facskó ◽  
...  
Keyword(s):  
Lacrimal Gland ◽  
Duct Cells ◽  
Gland Duct

Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

1995 ◽  
Vol 53 ◽  
pp. 972-973
Author(s):  
R H. Selinfreund ◽  
A. H. Cornell-Bell
Keyword(s):  
Membrane Potential ◽  
Confocal Microscopy ◽  
Patch Clamp ◽  
Electrical Activity ◽  
Time Lapse ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Pituitary Cells ◽  
Patch Clamp Recording ◽  
Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

scholarly journals Saliva and its potential in covid-19 cannot be ignored: a point of view

2021 ◽  
pp. 1-5
Author(s):  
Sukhvinder Singh Oberoi ◽  
Shabina Sachdeva ◽  
Shibani Grover ◽  
Vivek Sharma
Keyword(s):  
Salivary Gland ◽  
Epithelial Cells ◽  
Human Body ◽  
Point Of View ◽  
High Potential ◽  
Healthy Human ◽  
Duct Cells ◽  
Gland Duct

Abstract It has been demonstrated that salivary gland duct cells have similar receptors as ACE2-positive cells/keratin epithelial cells of the lung which have high potential to be infected by SARS-CoV 2 virus. The aerosols carrying virus have penetration into the healthy human body and lungs via inhalation through nose or mouth.

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