The mammalian kidney is an organ composed of numerous functional units or nephrons. Beyond the filtering glomerulus of each nephron, various tubular segments with distinct populations of epithelial cells sequentially span the kidney from cortex to medulla. The highly organized folding of the tubules results in a spatial distribution that allows intimate contact between various tubular subsegmen...

After 02 deprivation, tissue acidosis rapidly self-corrects. This study assessed the effect of this pH correction on the induction, and pathways, of posthypoxic proximal tubular injury. In addition, ways to prevent the resultant injury were explored. Isolated rat proximal tubular segments (PTSs) were subjected to hypoxia/reoxygenation (50/30 or 30/50 minutes) under the following incubation cond...

Intracellular iron reportedly mediates many forms of tissue injury, including ischemic and myohemoglobinuric acute renal failure. This action may be explained by the ability of iron to catalyze the formation of the highly toxic hydroxyl radical (.OH) from H202 via the Fenton/Haber-Weiss reactions. To assess whether renal tubular myoglobin/iron loading, induced by a physiological mechanism (endo...

BACKGROUND Proximal tubular epithelial cells express a surface C3-convertase activity which induces C fixation and insertion of the C5b-9 membrane attack complex (MAC) into the cell plasma membrane. The physiopathological consequences of this phenomenon are unknown. METHODS The effect of C fixation on the production of inflammatory mediators by human proximal tubular epithelial cells in cultu...

Diabetic nephropathy (DN), a major complication of diabetes, is characterized by hypertrophy, extracellular matrix accumulation, fibrosis and proteinuria leading to loss of renal function. Hypertrophy is a major factor inducing proximal tubular epithelial cells injury. However, the mechanisms leading to tubular injury is not well defined. In our study, we show that exposure of rats proximal tub...

S INCE the extensive studies of Pitts and coworkers (1-3) defined the characteristics of bicarbonate reabsorption in the normal subject, very little additional information has appeared concerning the nature of this transport system or its regulation. It was suggested then (2) that a dual process existed for the reabsorption of bicarbonate. A specific transport system in the proximal tubule was ...

A pathogenic role of p53 in AKI was suggested a decade ago but remains controversial. Indeed, recent work indicates that inhibition of p53 protects against ischemic AKI in rats but exacerbates AKI in mice. One intriguing possibility is that p53 has cell type-specific roles in AKI. To determine the role of tubular p53, we generated two conditional gene knockout mouse models, in which p53 is spec...

Renal micropuncture and clearance experiments were carried out in rats to study the effect of parathyroid hormone (PTH) on renal tubular HCO-/3 reabsorption. The rats were studied during an initial period of parathyroid deficiency (acute thyroidparathyroidectomy, TPTX) and during infusion of large amounts of bovine PTH. Under normal acid-base conditions, PTH administration to TPTX rats caused a...

BEEUWKES, REINIER III. E$ erent vascular patterns and early vasculartubular relations in the dog kidney. Am. J. Physiol. 221(5): 1361-1374. 197 1 .-Glomerular efferent vascular patterns were studied in cleared dog kidneys injected with silicone rubber. In addition, to show vascular-tubular relations, kidneys were perfusion-fixed in vivo and their vasculature was filled with silicone rubber. Pro...