ROCH-RAMEL, FRANCOISE, J. DI~ZI, FRANGOISE CHOM~TY, PIERRETTE MICHOUD, AND G. PETERS. Disposal of large urea overloads by the rat kidney: a micropuncture study. Am. J. Physiol. 2 1 a(6) : 1524-1532. 1970.-In rats overloaded with urea, at plasma concentrations of 60-80 mM, the proximal fractional reabsorption of urea was not impaired, whereas the cortical tissue-to-plasma urea concentration rati...

The purpose of this study was to determine the expression and distribution of band 3 in the collecting duct and connecting tubules of the kidney of the marmoset monkey (Callithrix jacchus), and to establish whether band 3 is expressed in type A intercalated cells. The intracellular localization of band 3 in the different populations of intercalated cells was determined by double-labeling immuno...

We studied the effects of cyclic AMP (cAMP) on HCO-3 transport by rabbit cortical collecting tubules perfused in vitro. Net HCO-3 secretion was observed in tubules from NaHCO3- loaded rabbits. 8-Bromo-cAMP-stimulated net HCO-3 secretion, whereas secretion fell with time in control tubules. Both isoproterenol and vasopressin (ADH) are known to stimulate adenylate cyclase in this epithelium; howe...

We wish to report here the finding of single cilia in epithelial cells of the parietal layer of Bowman's capsule, of the proximal convoluted tubule, of the distal tubule, and of the collecting tubule of the rat kidney. Despite the observation by light microscopy, many years ago, of cilia in the tubules of rabbit and human kidneys (16), and despite many electron microscopic studies of kidneys in...

The electrical properties of renal epithelia have been determined principally by micropuncture studies of neplhron segments located at the surface of the kidney. Deeper segments, owing to their inaccessibility to micropuncture cannot be studied directly, and consequently, their contribution to the ultimate formation of urine has been assessed by indirect methods. The introduction of the isolate...

Acidification of the urine is mediated by vectorial H+ transport from cells at a number of sites in the kidney. A proton ATPase has been described that appears to mediate a significant proportion of this H+ transport. In particular, in proximal tubule and collecting duct, there is evidence both for the presence of transporter protein and for H+ transport with features that have been identified ...

Expression and localization of members of the aquaporin (AQP) family (AQP1, 2, 3, 4, and 5) in the kidney of the musk shrew (Suncus murinus) was examined by immunohistochemistry. AQP1 was expressed in the proximal tubules and in the thin limb of the loops of Henle. AQP1 was the only water channel expressed in the proximal nephron examined, indicating that AQP1 may be an independent water transp...

A single gene defect leads to differing degrees of renal and hepatic involvement, with very different phenotypes and clinical outcome within even one affected family. [2] Kidneys are bilaterally enlarged and contain large numbers of cysts throughout the organ, due to the dilatation and elongation of renal collecting ducts. At birth, the interstitium and the rest of the tubules are normal but th...

The proliferation and morphological differentiation of bovine kidney collecting-tubule epithelial cells has been examined as a function of substrata and plasma factors. Collecting kidney tubule explant maintained in vitro gave rise to two distinct cell populations; one was composed mostly of fibroblastic cells whereas the other was epithelioid (EP cells). The proliferation of fibroblastic cells...

Medullary sponge kidney (MSK) is a congenital disorder that can affect one or both kidneys, or only part of one kidney. There are ectatic and cystic changes of the medullary and papillary collecting ducts. This cystic dilatation of tubules may have an effect on urinary flow. Cysts can be 1-7 mm in diameter. Cyst formation is commonly associated with the development of small calculi within the c...