The effect of vascular perfusion fixation on the ultrastructure of the juxtaglomerular apparatus of the rat.

After fixation by low pressure retrograde perfusion the electron microscopic picture of the rat JGA was studied and compared with the picture obtained after fixation by dripping and immersion. The most conspicuous difference was the presence of the basal compartments of the macula densa cells, which might land electron microscopic support to the tubulo-glomerular feedback theory. Among the JG granular cells, desmosome-like connected structures were seen. Crystalline and granule in granules specific secretion forms were frequent in the epitheloid cells.