Renal papillae

After peroral intake of nickel sulphate in mice, kidney damage appeared at the corticomedullary junction [296]. There was loss of renal tubular epithelial cells and protein loss, giving numerous hyaline casts in the renal tubules and collecting ducts, especially prominent in the renal papillae. 

Examine liver, gallbladder (mouse), stomach, spleen, pancreas, intestines, kidneys, adrenal gland, ureters, bladder, umbilical artery, genital organs, dorsal aorta, and caudal vena cava. Possible abnormalities that can be observed include absent renal papilla, dilated ureter(s), and displaced testis. 

Pentachloroethane given to rats by gavage during a two-year study caused chronic, diffuse kidney inflammation and renal papilla mineralization. A single dose also reduced hepatic cytochrome P450 content and microsomal epoxide hydrolase activities. Inhalation exposure of rabbits to pentachloroethane decreased their total antibody titres (lARC, 1986). 

The relevance of the kidney effects observed in the dietary studies in rats and mice is unclear because some of the findings (Crocker et al. 1988 David et al. 2000a, 2000b) indicate that they likely reflect exacerbation of age-, species-, and/or sex-related lesions by DEHP and are not accompanied by changes in kidney function. The mechanism of the effect induced by the lowest dietary dose of DEHP (i.e., mineralization of the renal papilla in rats exposed to 5.8 mg/kg/day) is unclear and might be consistent with male rat-specific precipitation of os -globulin (David et al. 2000a). Based on the available data, the kidneys do not demonstrate a consistent response to DEHP. 

ENLARGED TUBULAR CELLS AND NUCLEI IN RENAL PAPILLA AT 4 WEEKS... 

Blood flow to the two kidneys is approximately 22-25% of the cardiac output. The kidneys are supplied by the renal artery which enters the kidneys through the hilum and then branches progressively to form the interlobar arteries, arcuate arteries, interlobular arteries (also called radial arteries), and afferent arterioles, which lead to the glomerular capillaries. The distal ends of each glomerulus coalesce to form the efferent arteriole, which leads to a secondary capillary network, the peritubular capillaries which surround the renal tubules. The cortex receives approximately 90% of the blood flow compared to the medulla or papillae so blood-borne toxic molecules reaching the kidneys have a more toxic effect on the cortex, as compared to the medulla or renal papillae. The interstitial space is occupied by the fenestrated peritubular capillaries and a small number of fibroblast-like cells. Increase in thickness of interstitial space in pathological conditions is due to edema, proliferation of fibrous tissue, or infiltration of inflammatory cells (Guyton and Hall, 2006). 

The medulla/papillae are the target site for analgesics like phenylbutazone in horses. The loop of Henle is the target for fluoride ions and the glomeruli for immune complexes. The other anatomical location which is commonly affected by toxicant injury is the renal papillae. A classic example is... 

Developmental Mouse Gd6-15 (Swiss- (GW) Webster) I 3 (underdeveloped renal papillae cleft palate) Domingo et al. 1989a U02(C2H302)2 2H20... 

CAIs alter renal function primarily by inhibiting carbonic anhydrase in the proximal tubule, which results in decreased bicarbonate reabsorption. The net effect of the renal actions of acetazolamide therapy is alkaliniza-tion of the urine and metabolic acidosis. Metabolic acidosis results from the initial bicarbonate loss and persists with continued acetazolamide use. Moderate metabolic acidosis develops in most patients. Reabsorption of bicarbonate independent of carbonic anhydrase prevents severe acidosis. Initially, acetazolamide produces diuresis, but urinary output decreases with the development of metabolic acidosis. In addition, decreased urinary citrate excretion follows acetazolamide therapy and has been attributed to the metabolic acidosis it produces. A high urinary pH and low urinary citrate concentration are conducive to precipitation of calcium phosphate in both the renal papillae and the urinary tract. 

Anuria has occurred after silver nitrate irrigation for intractable bladder hemorrhage caused by cyclophosphamide chemotherapy (40). The level of obstruction was the ureterovesical junction on the one hand, and the collecting ducts of the renal papillae on the other. Therapy... 

By definition, papillary necrosis represents the development of irreversible damage within the parenchyma of the renal papillae. The papillae of the kidney contain the tip portions of the long loops of Henle, together with the terminal portions of the collecting duct complexes, which open in to the minor calyces. The minor calyces of the kidneys representing the first location in the upper renal outflow tract into which mine is collected before it travels into the renal pelvis and into the urinary bladder via the ureters. 

Oliver JA et al (2004) The renal papilla is a niche for adult kidney stem cells. J Clin Invest 114(6) 795-804... 

Collecting tubules from the rabbit renal papillae synthesize 6-keto-PGF from AA.98 1 ... 

FIGURE 5.8 A series of H MAS-NMR spectra of intact renal papilla obtained from rats 24 h after dosing with the model papillotoxin 2-bromoethanamine at 150 mg/kg. 

Papillary necrosis is a form of chronic interstitial nephritis characterized by necrosis of the renal papillae, which are the regions of the kidney where the collecting ducts enter the renal pelvis. Analgesic use is the most common cause of papillary necrosis, accounting for 36% of all cases. ... 

Renal Effects. No reports of renal effects in humans were located. In nonhuman animals, mild kidney effects have been observed following oral exposure to selenium compounds. These effects include hydropic degeneration in sheep exposed to selenite and nephropathy in monkeys exposed to selenomethionine. Rats appear to be more sensitive than mice to the renal effects of selenium compounds. A dose-related increase in renal papilla degeneration, described as mild to minimal, was observed in rats treated with selenate or selenite in the drinking water, while the only kidney effect noted in mice treated with sodium selenate or selenite in the drinking water was increased kidney weight. Selenium sulfide administration to mice has, however, been shown to produce interstitial nephritis. 

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