Glomerular Capillary Endothelium Research Articles

Quelques observations ultrastructurales sur le rein

The authors describe four electron microscope observations on the kidney of different mammals: 1. Ring shaped mitochondria in the epithelium cells of Bowman's capsule and uriniferous tubules. 2. Centrioles in proximal and distal tubule cells, in the endothelium of glomerular and peritubular capillaries, in epithelioid cells of the afferent arteriole, in smooth muscle fibers, and in an interstitial cell. 3. Multivescular bodies (=vacuole-containing bodies), with a diameter ranging from 1500 to 7000 A, in the renal corpuscules and the proximal and distal tubule cells, in endothelium cells of arterioles, in smooth muscle fibers and in interstitial cells. 4. Pores in the endothelium not only of the glomerular, but also of the intertubular capillaries.

THE FORMATION OF URINE

The formation of urine is the result of the simultaneous occurrence of three processes, only one of which is explicable in terms of known forces. These processes are: (1) glomerular filtration, or the passage of a colloid-free filtrate of blood plasma through the glomerular capillary endothelium and its investing squamous epithelium owing to an excess of hydrostatic over colloid osmotic pressure; (2) tubular excretion, or the passage of solutes from the plasma in the peritubular capillaries through the cells of the proximal convolution of the tubule to its lumen; (3) tubular resorption, or the partial removal of solutes and water from the lumen of the distal half of the tubule by its cells (the corrective conservation of certain solids and of water wastefully excreted by the renal corpuscle). The adequacy of these processes in the indispensable regulation of the composition of the plasma is dependent on the functional integrity of