Changes in myoendocrine cells in rat right atrium at hypertension and during pharmacological lowering of blood pressure

Autor: V. F. Maksimov, G. S. Yacobson, I. M. Korostyshevskaya, N. S. Rudenko, A. L. Markel, S. A. Kurganov
Rok vydání: 2015
Předmět:
Zdroj: Cell and Tissue Biology. 9:30-39
ISSN: 1990-5203
1990-519X
DOI: 10.1134/s1990519x1501006x
Popis: Atrial cardiomyocytes, along with their contractile function, carry out synthesis, storage in secretory granules, and release of natriuretic peptides. The main physiological effect of natriuretic peptides lies in counteracting the function of the renin-angiotensin-aldosterone system. However, whether they participate in the development of hypertension remains controversial. The purpose of this study is use implement electron microscopy to evaluate the secretory activity of atrial myoendocrine cells in the rats with inherited stress induced arterial hypertension (ISIAH strain). We found that, in ISIAH rats, under conditions of a blood pressure level of 180 mm Hg, myoendocrine cells of the atria show signs of increased synthesis and excessive accumulation and release of natriuretic peptides compared with normotensive control. In turn, in rats treated with losartan (inhibitor of angiotensin receptors), a steady decline in blood pressure to 140 mm Hg was accompanied by alteration in the composition, reduction in the number and diameter of the secretory granules, reduction in lamellar complexes, and an increase in intracellular degradation of stockpiles of secretory products. In parallel, hyperemia of capillaries and interstitial edema were observed in the myocardium. Thus, our results indicate that, in rats with severe hereditary hypertension, the secretory activity of myoendocrine cells increases sharply and is directly related to blood pressure levels. These results support the idea that there is active participation of natriuretic peptides in the regulation of hemodynamics during cardiovascular disease.
Databáze: OpenAIRE
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