Inhibition by ouabain of palytoxin-induced catecholamine secretion and calcium influx into cultured bovine adrenal chromaffin cells

Yoshizumi, Masanori; Ishimura, Yasuko; Masuda, Yutaka; Kato, Itsuo; Oka, M.

doi:10.1016/0006-2952(94)90377-8

Cited by 3 publications

(1 citation statement)

References 19 publications

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“…This supports previous observations which showed that cardiac glycosides inhibit various biological actions of PTX (Ishida et al 1983(Ishida et al , 1985Ozaki et al 1984;Yoshizumi et al 1994), and suggests that PTX acts on or near the ouabain-binding site of Na + , K + -ATPase.…”

Section: Discussionsupporting

confidence: 90%

Palytoxin-induced increase in endothelial Ca2+ concentration in the rabbit aortic valve

Amano

Sato

Hori

et al. 1997

Naunyn-Schmiedeberg's Arch Pharmacol

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Palytoxin (PTX) is one of the most potent toxins isolated from marine coelenterates of the genus Palythoa. It induces depolarization in various types of cells by increasing the permeability for monovalent cations. It has been reported that PTX induces endothelium-dependent relaxation of vascular smooth muscle. In this study, we examined the effect of PTX on the cytosolic Ca2+ concentration ([Ca2+]i) in the endothelium of rabbit aortic valves loaded with fluorescent Ca2+ indicators, fura-PE3 or fluo-3. PTX (10 pM-300 nM) irreversibly increased endothelial [Ca2+]i in a concentration-dependent manner. ATP and thapsigargin also increased [Ca2+]i. Imaging of [Ca2+]i with a confocal microscope revealed that PTX increased [Ca2+]i in all endothelial cells studied (n = 13). An inorganic Ca2+ entry blocker, La3+ (30 microM), had no effect on the increase in [Ca2+]i induced by PTX whereas it inhibited the sustained phase of the increase in [Ca2+]i induced by ATP or thapsigargin. The PTX-induced increase in [Ca2+]i was partially inhibited by ouabain and was abolished by removal of external Ca2+ although decrease of Na+ concentration in the incubation medium was ineffective. Activation of protein kinase C by 1 microM 12-deoxyphorbol 13-isobutyrate or inhibition of phosphatase by 10 nM calyculin-A had no effect on the increase in [Ca2+]i induced by PTX, whereas both agents inhibited the sustained phase of the increase in [Ca2+]i induced by ATP or thapsigargin. Mn2+ influx, measured by the quenching of fura-PE3 fluorescence, was accelerated by ATP or thapsigargin, but not by PTX. These results suggest that PTX increases [Ca2+]i in the endothelium of the rabbit aortic valve by increasing Ca2+ influx through a pathway which is different from that activated by ATP or thapsigargin.

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Section: Discussionsupporting

confidence: 90%

Palytoxin-induced increase in endothelial Ca2+ concentration in the rabbit aortic valve

Amano

Sato

Hori

et al. 1997

Naunyn-Schmiedeberg's Arch Pharmacol

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Renal Ion-Translocating ATPases: The P-Type Family

Horisberger

Doucet

2008

Seldin and Giebisch's the Kidney

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Production of Functionally Active Palytoxin-like Compounds by Mediterranean <i>Ostreopsis cf. siamensis</i>

Cagide

Louzao²,

Espiña³

et al. 2009

Cell Physiol Biochem

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Background and purpose: Dinoflagellates from the genus Ostreopsis have been related to the production of palytoxin and analogues. Based on that, this paper describes functional studies of crude extracts from Ostreopsis cf. siamensis collected in the Mediterranean Sea in order to biochemically characterize their toxic compounds. Methods: We compared the effects of 5 crude dinoflagellates extracts with a commercially available palytoxin and a purified Ostreopsis ovata extract on metabolic activity, membrane potential, and cytosolic calcium levels by using fluorescent dyes. Results: All the extracts resulted to be neurotoxic. In addition, all of them induced a membrane depolarization and a calcium increment that were abolished when preincubating with ouabain, an inhibitor of the Na⁺/K⁺ pump. Conclusion: The effects observed were quite close to those induced by palytoxin and the Ostreopsis ovata extract as well, suggesting that Ostreopsis cf. siamensis is actually producing palytoxin-like compounds that are highly toxic and functionally active.

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Inhibition by ouabain of palytoxin-induced catecholamine secretion and calcium influx into cultured bovine adrenal chromaffin cells

Cited by 3 publications

References 19 publications

Palytoxin-induced increase in endothelial Ca2+ concentration in the rabbit aortic valve

Palytoxin-induced increase in endothelial Ca2+ concentration in the rabbit aortic valve

Renal Ion-Translocating ATPases: The P-Type Family

Production of Functionally Active Palytoxin-like Compounds by Mediterranean <i>Ostreopsis cf. siamensis</i>

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