EFFECTS OF DIADENOSINE POLYPHOSPHATES ON INWARD RECTIFIER POTASSIUM CURRENTS IN RAT CARDIOMYOCYTES
Abstract
Diadenosine polyphosphates are now considered as a novel class of endogenous paracrine signal compounds. The putative role of these compounds in pathogenesis of myocardial infarction was proposed, since the concentration of diadenosine polyphosphates increases in the cardiac tissue following the ischemic lesion and myocardial necrosis. Therefore, possible effects of diadenosine polyphosphates on cardiac electrical activity and their ionic mechanisms are of considerable interest. In the present study we have investigated the effects of diadenosine pentaphosphate (Ap5A), diadenosine tetraphosphate (Ap4A) and NAD+ on transmembrae currents, belonging to the family of potassium inward rectifiers: background inward rectifier (IK1), ATP-dependent potassium current (IKATP) and acetylcholine-dependent current (IKACh). Experiments were performed using the whole-cell patch-clamp technique on isolated atrial and ventricular rat cardiomyocytes. We have demonstrated that none of tested adenine compounds affects IK1 and IKACh. Ap5A (10–5М) induces considerable decrease of both inward and outward component of IKATP by 22,1 and 19% of control value, respectively. Higher concentration of Ap5A (3×10–5М) produces stronger suppression of IKATP — by 47,5 and 37,8%, respectively. However, IKATP turned out to be insensitive to Ap4A and NAD+.
About the Authors
D. V. Abramochkin
кафедры физиологии человека и животных биологического факультета МГУ
Russian Federation
Russian Federation
K. B. Pustovit
кафедры физиологии человека и животных биологического факультета МГУ
Russian Federation
Russian Federation
T. S. Filatova
кафедры физиологии человека и животных биологического факультета МГУ
Russian Federation
Russian Federation
References
1. Baxi M.D., Vishwanatha J.K. Diadenosine polyphosphates: their biological and pharmacological significance // J. Pharmacol. Toxicol. Methods. 1995. Vol. 33. N 3. P. 121–128.
2. Burnstock G. Purine and pyrimidine receptors // Physiol. Rev. 2007. Vol. 87. N 2. P. 659–797.
3. Smyth L.M., Yamboliev I.A., Mutafova-Yambolieva V.N. N-type and P/Q-type calcium channels regulate differentially the release of noradrenaline, ATP and beta-NAD in blood vessels // Neuropharmacology. 2009. Vol. 56. N 2. P. 368–378.
4. Yamboliev I.A., Smyth L.M., Durnin L., Dai Y., Mutafova-Yambolieva V.N. Storage and secretion of beta-NAD, ATP and dopamine in NGF-differentiated rat pheochromocytoma PC12 cells // Eur. J. Neurosci. 2009. Vol. 30. N 5. P. 756–768.
5. Flores N.A., Stavrou B.M., Sheridan D.J. The effects of diadenosine polyphosphates on the cardiovascular system // Cardiovasc. Res. 1999. Vol. 42. N 1. P. 15–26.
6. Пустовит К.Б., Кузьмин В.С., Сухова Г.С. Влияние внеклеточного никотинамидадениндинуклеотида (NAD+) на сократительную и биоэлектрическую активность сердца крысы // Рос. физиол. журн. им. И.М. Сеченова. 2014. Т. 100. № 4. С. 445–457.
7. Пустовит К.Б., Кузьмин В.С., Сухова Г.С. Влияние внеклеточного никотинамидадениндинуклеотида (NAD+) на биоэлектрическую активность пейсмекера и проводящей системы сердца // Бюл. эксп. биол. мед. 2015. Т. 159. № 2. С. 4–6.
8. Hibino H., Inanobe A., Furutani K., Murakami S., Findlay I., Kurachi Y. Inwardly rectifying potassium channels: their structure, function, and physiological roles // Physiol. Rev. 2010. Vol. 90. N 1. P. 291–366.
9. Boyett M.R., Kodama I., Honjo H., Arai A., Suzuki R., Toyama J. Ionic basis of the chronotropic effect of acetylcholine on the rabbit sinoatrial node // Cardiovasc. Res. 1995. Vol. 29. N 6. P. 867–878.
10. Isenberg G., Klockner U. Calcium tolerant ventricular myocytes prepared by preincubation in a “KB-medium” // Pflugers Arch. 1982. Vol. 395. N 1. P. 6–18.
11. Brouillette J., Clark R.B., Giles W.R., Fiset C. Functional properties of K+ currents in adult mouse ventricular myocytes // J. Physiol. 2004. Vol. 559. Pt. 3. P. 777–798.
Review
For citations:
Abramochkin D.V., Pustovit K.B., Filatova T.S. EFFECTS OF DIADENOSINE POLYPHOSPHATES ON INWARD RECTIFIER POTASSIUM CURRENTS IN RAT CARDIOMYOCYTES. Vestnik Moskovskogo universiteta. Seriya 16. Biologiya. 2015;(4):3-7. (In Russ.)
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