Bovine adrenals and hypothalamus are a major source of proscillaridin A- and ouabain-immunoreactivities

Li, Suqin; Eim, C.; Kirch, Ulrike; Lang, R.; Schoner, Wilhelm

doi:10.1016/s0024-3205(98)00023-x

Cited by 45 publications

(32 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All these data support earlier suggestions that the ER Ca 2+ store contributes to maintain healthy secretory responses elicited by depolarising pulses applied to bovine chromaffin cells [115,116]. The fact that endogenous ouabain has been identified in human plasma [157,158] and that bovine adrenal cortex is particularly rich in endogenous ouabain [159], suggests a physiological role of this mediator in the control of Ca 2+ -dependent vesicle flow from a reserve pool towards ready-release and immediate-release vesicle pools at subplasmalemmal sites [7].…”

Section: Calcium Effluxsupporting

confidence: 89%

Cytosolic organelles shape calcium signals and exo–endocytotic responses of chromaffin cells

et al. 2012

View full text Add to dashboard Cite

a b s t r a c tfluxes between the different cell compartments support the proposal that the chromaffin cell has developed functional calcium tetrads formed by calcium channels, cytosolic calcium buffers, the endoplasmic reticulum, and mitochondria nearby the exocytotic plasmalemmal sites. These tetrads shape the Ca 2+ transients occurring during cell activation to regulate early and late steps of exocytosis, and the ensuing endocytotic responses. The different patterns of catecholamine secretion in response to stress may thus depend on such local [Ca 2+ ] c transients occurring at different cell compartments, and generated by redistribution and release of Ca 2+ by cytoplasmic organelles. In this manner, the calcium tetrads serve to couple the variable energy demands due to exo-endocytotic activities with energy production and protein synthesis.

show abstract

Section: Calcium Effluxsupporting

confidence: 89%

Cytosolic organelles shape calcium signals and exo–endocytotic responses of chromaffin cells

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Endogenous ouabain was found to be synthesized and stored in the adrenal cortex (38) and the hypothalamus (39,40). Its concentration is increased under physiological conditions, for example during exercise (5), and under pathological conditions such as hypertension (6-9) and eclampsia (10).…”

Section: Discussionmentioning

confidence: 99%

Ouabain modulates epithelial cell tight junction

Larre

Lázaro

Contreras

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

102

View full text Add to dashboard Cite

Epithelial cells treated with high concentrations of ouabain (e.g., 1 μM) retrieve molecules involved in cell contacts from the plasma membrane and detach from one another and their substrates. On the basis of this observation, we suggested that ouabain might also modulate cell contacts at low, nontoxic levels (10 or 50 nM). To test this possibility, we analyzed its effect on a particular type of cell-cell contact: the tight junction (TJ). We demonstrate that at concentrations that neither inhibit K + pumping nor disturb the K + balance of the cell, ouabain modulates the degree of sealing of the TJ as measured by transepithelial electrical resistance (TER) and the flux of neutral 3 kDa dextran (J DEX ). This modulation is accompanied by changes in the levels and distribution patterns of claudins 1, 2, and 4. Interestingly, changes in TER, J DEX , and claudins behavior are mediated through signal pathways containing ERK1/2 and c-Src, which have distinct effects on each physiological parameter and claudin type. These observations support the theory that at low concentrations, ouabain acts as a modulator of cell-cell contacts.claudins | c-Src | ERK1/2 | Madin-Darby canine kidney | occludin S everal lines of evidence, including the high affinity and specificity of ouabain for Na + ,K + -ATPase, suggest that endogenous ouabain analogs might exist. In keeping with this possibility, Hamlyn et al.(1) demonstrated the presence of a substance in plasma that cannot be distinguished from ouabain even by specific antibodies and mass spectrometry (1-4). Endogenous ouabain levels are increased during exercise (5) and in pathological conditions such as arterial hypertension (6-9) and eclampsia (10), raising the possibility that ouabain functions as a hormone and prompting efforts to elucidate physiological role.We have previously demonstrated that ouabain acts on cell-substrate and cell-cell contacts in Madin-Darby canine kidney (MDCK) cells. At 1 μM, ouabain binding to the Na + ,K + -ATPase results in pump inhibition and disassembly of molecules from the tight, adherens, and focal junctions (i.e., a P→A mechanism from pump to adhesion) (11). Consistent with these results, Rajasekaran et al. (12) have observed that 0.5 μM ouabain acts on the tight junction (TJ), decreasing transepithelial electrical resistance (TER) and increasing mannitol and inulin permeability in cultures of human retinal pigment epithelial cells. Furthermore, we have shown that in cocultures of wild-type MDCK and ouabain-resistant MDCK cells, ouabain treatment increases the expression of connexin 32, but not 26 or 43, and increases cell-cell communication via gap junctions to rescue the wild-type cells (13). Although these effects indicate that toxic levels of ouabain affect the structure and function of cell-cell junctions, we do not know how lower levels of ouabain affect adhesive structures.In the present work, we focus on this question and demonstrate that 10 nM ouabain affects neither Na + ,K + -ATPase nor the K + balance of the cells and does not indu...

show abstract

“…12 Bufadienolides have been found not only in toads but also in some animal species and plants, 13 but the series of studies by Bagrov et al 9 on MBG is strikingly interesting, because bufadienolides were actually found in mammals. Moreover, Lichtstein et al 14 and Li et al 15 found 19-norbufalin in the human cataractous lenses and proscillaridin-like immunoreactivity in the human plasma, respectively. Very recently, we have identified telecinobufagin (TCB), a 2-hydrogen-added form of MBG, by liquid chromatography (LC)/mass spectrometry (MS), as well as MBG in the human plasma.…”

mentioning

confidence: 97%

Novel Digitalis-Like Factor, Marinobufotoxin, Isolated From Cultured Y-1 Cells, and Its Hypertensive Effect in Rats

et al. 2007

View full text Add to dashboard Cite

Abstract-Marinobufagenin and telecinobufagin have been identified as digitalis-like factors in mammals. In toads, marinobufagenin-related compounds, such as marinobufotoxin (MBT), have been isolated in some tissues but not in mammals, and its biological action has not been elucidated. Herein, we aimed to explore the possible production and/or secretion of MBT and the biological action in rats. First, the MBT in culture supernatant of the adrenocortical-originated cell line Y-1 was analyzed by high-performance liquid chromatography and sensitive ELISA for marinobufagenin-like immunoreactivity. Moreover, the structural information was obtained by mass spectrometry. To determine the biological action, MBT (9.6 and 0.96 g/kg per day) was intraperitoneally infused via an osmotic minipump for 1 week. Blood pressure and renal excretion of marinobufagenin-like immunoreactivity were measured. Marinobufagenin-like immunoreactivity was found in Y-1 cell culture media, and the concentration increased until 24 hours. The structural analysis suggested that marinobufagenin-like immunoreactivities were marinobufagenin and MBT, and tandem mass spectrum analysis revealed them with the specific daughter ions. The highest sensitive ELISA-positive peak of marinobufageninlike immunoreactivity in the media was MBT. Continuous administration of MBT in rats for 1 week significantly increased systolic blood pressure and renal excretion of marinobufagenin-like immunoreactivity compared with control rats (135Ϯ3.0 versus 126Ϯ2.0 mm Hg and 1.41Ϯ0.286 versus 0.34Ϯ0.064 ng/day, respectively). These data suggest that MBT, arginine-suberoyl ester of marinobufagenin, can be a novel digitalis-like factor with hypertensive action and is secreted from the adrenocortical cells.

show abstract

Bovine adrenals and hypothalamus are a major source of proscillaridin A- and ouabain-immunoreactivities

Cited by 45 publications

References 18 publications

Cytosolic organelles shape calcium signals and exo–endocytotic responses of chromaffin cells

Cytosolic organelles shape calcium signals and exo–endocytotic responses of chromaffin cells

Ouabain modulates epithelial cell tight junction

Novel Digitalis-Like Factor, Marinobufotoxin, Isolated From Cultured Y-1 Cells, and Its Hypertensive Effect in Rats

Contact Info

Product

Resources

About