Electrophysiological study of coupling between cultured cells of the mouse mammary gland in five distinct physiological states

Shen, Sheldon S.; Hamamoto, Susan; Pitelka, Dorothy R.

doi:10.1007/bf01868971

Cited by 13 publications

(8 citation statements)

References 27 publications

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“…The epithelial cells of the nipple are electrically connected to each other. There is a free flow of small molecules such as nucleotides and ions (Shen et al 1976;Czerski et al 2005). The flow is possible thanks to the presence of ion-metabolic connection between the cells (gap junction), which were confirmed by electron microscopy (Pitelka et al 1973;Peracchia and Dulhunky 1976).…”

Section: Discussionmentioning

confidence: 87%

The patterns of myoelectrical activity and reaction for teat stimulation recorded in highly productive dairy cows’ udders

et al. 2013

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The aim of the study was to evaluate electrical properties of the mammary gland of dairy cow during manual and mechanical milking and to adapt the electrographic method for analysis of udder physiology. Udder myoelectrical activity was measured on 10 healthy highly productive dairy cows of Slovak Pied cattle breed. The electrical activity of four quarters of the udder was recorded simultaneously using four bipolar electrodes. The udder was stimulated by delicate twofinger massage, manual milking and mechanical milking. During the experiment the duration of the reaction for stimulation and the amplitude of spike dischargers were listed. The udder stimulation through palpational massage of the teat end, manual and mechanical milking caused immediate reaction. The udder responded to stimulation with an increase in myoelectrical activity: increase in discharge frequency to 2.33 ± 0.6 per min and an increase in discharge amplitude with the average of 457 ± 147 µV. The average count of spike discharges was 3.86 ± 0.97, the average duration of the action potential was 8.12 ± 1.68 s and the average myoelectrical index was 31 ± 4%. Manual milking caused the highest increase in the udder myoelectrical activity. Evaluation of the mammary gland myoelectrical activity may provide an alternative method to study milk ejection disorders and to diagnose mastitis. Myoelectrical activity, udder health, two-finger massage stimulation, mechanical milkingThe electrical activity is an attribute of every living cell. Thanks to the difference in electric potential between the inside of the cell and the outside membrane, the cell has the ability to response to a stimulus. The recording of the udder myoelectrical activity may be an alternative method to study the function of the gland. The method could be used in the diagnosis of milk ejection disorders and other diseases of the mammary gland. The myoelectrical activity analysis is an advanced examination method for indirect tracking of the muscle contractility through reception of action potentials using implanted electrodes. The myoelectrical activity has a direct impact on the tissue contraction. It is a minimally invasive method, so the information obtained during the examination is a reflection of physiological process occurring in the organs.The aim of the study was to evaluate electrical properties of the mammary gland of dairy cow during manual and mechanical milking and to adapt the electrographic method to the analysis of udder physiology. Materials and Methods Animals and udder examinationUdder myoelectrical activity was measured on 10 highly productive dairy cows of Slovak Pied cattle breed. Before the recording, a sample of milk from each udder's quarter was collected in a sterile way for examination to rule out bacterial infection and inflammation. Only animals qualified as healthy in the milk test were used for the study.

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Section: Discussionmentioning

confidence: 87%

The patterns of myoelectrical activity and reaction for teat stimulation recorded in highly productive dairy cows’ udders

et al. 2013

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“…Consistent with the literature, differentiation of these monolayers was variable despite several manipulations including treatment of filters with matrix proteins, addition of DEX, or culturing with an air-liquid interface. Thus, cultures were divided into low resistance (mean R t ϭ 323 Ϯ 48 ohms⅐cm 2 , n ϭ 36) or high resistance groups (mean R t ϭ 1240 Ϯ 321 ohms⅐cm 2 , n ϭ 9). Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Electrophysiology-Coverslips or filter inserts with cell monolayers were placed in a chamber on an inverted microscope and perfused with bathing medium at a rate of 0.5 ml/min containing (in mM): NaCl 140, KCl 4, MgCl 2 SO) was prepared immediately before the experiment. The patch pipettes were double step-pulled from borosilicate glass capillaries (Hilgenberg, Malsfeld, Germany) using a vertical puller (PB-7, Narishige).…”

Section: Methodsmentioning

confidence: 99%

“…After forming confluent monolayers when grown in vitro, several ion transporting epithelia form fluidfilled hemicysts, or domes (1)(2)(3). These domes appear in small areas where cells detach from the underlying glass or plastic surface upon which the cells are plated.…”

mentioning

confidence: 99%

“…This in vitro culture system can be exploited uniquely to study the development of epithelial polarity, junctional formation, transport function, and cell-substrate interactions that are required for fluid accumulation between the monolayer and the underlying surface. The cells found in the domes are polarized, contain markers of epithelial differentiation, including tight junctions and gap junctional intercellular communications, and stain positively for cytokeratins (2)(3)(4). Whether morphological differentiation of cells forming domes correlates with the functional maturation of transepithelial ion transport is not known.…”

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confidence: 99%

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Differentiation of Epithelial Na+ Channel Function

Shlyonsky¹,

Goolaerts²,

Beneden

et al. 2005

Journal of Biological Chemistry

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Confluent monolayers of epithelial cells grown on nonporous support form fluid-filled hemicysts called domes, which reflect active ion transport across the epithelium. Clara-like H441 lung adenocarcinoma cells grown on glass supports and exposed to 50 nM dexamethasone developed domes in a time-dependent fashion. Uplifting of small groups of cells occurred within 6 -12 h, well formed domes appeared between 24 and 48 h, and after 7 days, individual domes started to merge. Cells inside of domes compared with those outside domes, or with monolayers not exposed to dexamethasone, differed by higher surfactant production, an increased cytokeratin expression, and the localization of claudin-4 proteins to the plasma membrane. In patch clamp studies, amiloride-blockable sodium currents were detected exclusively in cells inside domes, whereas in cells outside of domes, sodium crossed the membrane through La 3؉ -sensitive nonspecific cation channels. Cells grown on permeable support without dexamethasone expressed amiloride-sensitive currents only after tight electrical coupling was achieved (transepithelial electrical resistance (R t ) > 1 kilohm). In real-time quantitative PCR experiments, the addition of dexamethasone increased the content of claudin-4, occludin, and Na ؉ channel ␥-subunit (␥-ENaC) mRNAs by 1.34-, 1.32-, and 1.80-fold, respectively, after 1 h and was followed by an increase at 6 h in the content of mRNA of ␣-and ␤-ENaC and of ␣1-and ␤1-Na,K-ATPase. In the absence of dexamethasone, neither change in gene expression nor cell uplifting was observed. Our data suggest that during epithelial differentiation, coordinated expression of tight junction proteins precedes the development of vectorial transport of sodium, which in turn leads to the fluid accumulation in basolateral spaces that is responsible for dome formation.Epithelial tissues typically transport ions and water between two compartments. After forming confluent monolayers when grown in vitro, several ion transporting epithelia form fluidfilled hemicysts, or domes (1-3). These domes appear in small areas where cells detach from the underlying glass or plastic surface upon which the cells are plated. Presumably, the apical to basolateral transport of fluid increases the fluid volume underneath the monolayer causing the appearance of domes. This in vitro culture system can be exploited uniquely to study the development of epithelial polarity, junctional formation, transport function, and cell-substrate interactions that are required for fluid accumulation between the monolayer and the underlying surface. The cells found in the domes are polarized, contain markers of epithelial differentiation, including tight junctions and gap junctional intercellular communications, and stain positively for cytokeratins (2-4). Whether morphological differentiation of cells forming domes correlates with the functional maturation of transepithelial ion transport is not known.The Clara-like H441 lung papillary adenocarcinoma cell line has been used as a glucocorticoid-an...

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