DEGREE OF GRANULARITY OF ATRIAL CARDIOCYTES - MORPHOMETRIC STUDY IN RATS SUBJECTED TO DIFFERENT TYPES OF WATER AND SODIUM LOAD

Abstract

Morphometric analysis was applied to the evaluation of the atrial cardiocyte specific granules, in rats subjected to different types of water and Na load. In control animals, the right atrium was more granulated than the left one and the interauricular septum. Ipsilateral atrium and auricle had the same index of granularity. Five types of water and Na load were tested: I. full water restriction, II. Na restriction with normal water intake, III. controls, IV. Na overloading, V. Na and DOCA overloading. From groups I to V, the index of granularity decreased progressively. The same phenomenon did not appear in the left atrium, except for group II (Na restriction) whose index was higher (P < 0.001) than in the other groups. An analogy between these cells and the myoepithelioid cells of the juxtaglomerular apparatus was suggested.