The relationship between renal warm ischemia time and glomerular loss. An experimental study in a pig model

Abstract Purpose: To investigate the glomerular number after different warm ischemia times. Methods: Thirty two pigs were assigned into four groups. Three groups (G10, G20, and G30) were treated with 10, 20, and 30 minutes of left renal warm ischemia. The sham group underwent the same surgery without renal ischemia. The animals were euthanized after 3 weeks, and the kidneys were collected. Right kidneys were used as controls. The kidney weight, volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted mean glomerular volume, and the total number of glomeruli per kidney were obtained. Serum creatinine levels were assessed pre and postoperatively. Results: Serum creatinine levels did not differ among the groups. All parameters were similar for the sham, G10, and G20 groups upon comparison of the right and left organs. The G30 group pigs' left kidneys had lower weight, volume, and cortical-medullar ratio and 24.6% less glomeruli compared to the right kidney. A negative correlation was found between warm ischemia time and glomerular number. Conclusions: About one quarter of glomeruli was lost after 30 minutes of renal warm ischemia. No glomeruli loss was detected before 20 minutes of warm ischemia. However, progressive glomerular loss was associated with increasing warm ischemia time.

A case of ruptured renal cortical arteriovenous malformation of the right testicular vein in hemorrhagic fever with renal syndrome

Hemorrhagic fever with renal syndrome (HFRS) is an acute viral disease characterized by fever, hemorrhage, and renal failure. Among the various hemorrhagic complications of HFRS, the spontaneous rupture of an arteriovenous malformation of the testicular vessels with a retroperitoneal hematoma is a rare finding. Here, we report a case of HFRS complicated by a massive retroperitoneal hematoma that was treated with transcatheter arterial embolization.

Ultrastructural changes in the kidney cortex of rats treated with lead acetate / Cambios ultraestructurales en la corteza renal de ratas tratadas con acetato de plomo

The purpose of this study was to investigate the ultrastructural effects of lead on the kidney cortex of rats. Wistar Albino rats (180-200g body weight) were divided into a controlled and lead acetate-exposed group. Rats received lead acetate at 500 ppm in their drinking water for 60 days. Both groups were fed with the same standard food, but lead acetate was added to the drinking water. During the experimental period, blood samples were taken from the abdominal aorta of the anesthetised animals. At the end of exposure, body weight and blood lead levels were measured. The kidney tissue samples were prepared and analyzed by light and transmission electron microscopy. Cortical renal tubules show various degenerative changes with focal tubular necrosis invaded by inflammatory cells. The ultrastructural alterations found in lead acetate-treated rats were a diminution in the amount of filtration slits, increased fusion of foot processes in epithelial cells of the glomeruli, increase of lysosomal structures and pinocytic vesicles as well as large mitochondria in proximal tubule cells.

El propósito de este estudio fue investigar los efectos ultraestructurales del plomo en la corteza renal. Ratas Wistar albinas (180-200g de peso corporal) fueron divididas en grupo control y grupo experimental. Las ratas recibieron 500 ppm de acetato de plomo en el agua potable durante 60 días. Ambos grupos fueron alimentados con el mismo alimento estándar, pero acetato de plomo se le añadió al agua potable al grupo experimental. Durante el período experimental, se tomaron bajo anestesia muestras sanguíneas desde la parte abdominal de la aorta. Al final de la exposición, fueron medidos el peso corporal y los niveles de plomo en la sangre. Fueron preparadas las muestras de tejido renal y se analizaron mediante microscopía de luz y electrónica de transmisión. Los túbulos renales corticales mostraron varios cambios degenerativos con necrosis tubular focal invadida por células inflamatorias. Las alteraciones ultraestructurales encontradas en las ratas tratadas con acetato de plomo correspondieron a una disminución en la cantidad de ranuras de filtración, aumento de la fusión de los procesos podales en las células epiteliales de los glomérulos, aumento de la estructura lisosomal y las vesículas pinocíticas, así como grandes mitocondrias en las células del túbulo proximal.

Role of nitric oxide and prostaglandin in the maintenance of cortical and renal medullary blood flow

This study was undertaken in anesthetized dogs to evaluate the relative participation of prostaglandins (PGs) and nitric oxide (NO) in the maintenance of total renal blood flow (TRBF), and renal medullary blood flow (RMBF). It was hypothesized that the inhibition of NO should impair cortical and medullary circulation because of the synthesis of this compound in the endothelial cells of these two territories. In contrast, under normal conditions of perfusion pressure PG synthesis is confined to the renal medulla. Hence PG inhibition should predominantly impair the medullary circulation. The initial administration of 25 µM kg-1 min-1 NG-nitro-L-arginine methyl ester produced a significant 26 percent decrease in TRBF and a concomitant 34 percent fall in RMBF, while the subsequent inhibition of PGs with 5 mg/kg meclofenamate further reduced TRBF by 33 percent and RMBF by 89 percent. In contrast, the initial administration of meclofenamate failed to change TRBF, while decreasing RMBF by 49 percent. The subsequent blockade of NO decreased TRBF by 35 percent without further altering RMBF. These results indicate that initial PG synthesis inhibition predominantly alters the medullary circulation, whereas NO inhibition decreases both cortical and medullary flow. This latter change induced by NO renders cortical and RMBF susceptible to a further decrease by PG inhibition. However, the decrease in medullary circulation produced by NO inhibition is not further enhanced by subsequent PG inhibition.

Renovasculopathies of hypertension in hispanic residents of Dallas, Texas

Background. Mean blood pressure levels (MBP) appear to rise with age slowly in the population of Mexico City and more swiftly in the U.S. in the black and white population, judging from publoshed survery data. Some evidence suggests that MBP rises at intermediate rates in Hispanics in the U.S. Method. This question is explored here in two ways, by review of published survery data and by a novel approach that uses renal tissue obtained from forensic autopsies to estimate MBP. Past studies have revealed good agreement between the two methods of estimating MBP. Results. Good agreement is again observed from the results of this study. Results from both methods agree that MBP is much lower at all ages in Mexican men and women than in blacks and whites in the U.S. Both methods also agree that hispanics in the U.S. demonstrate an intermediate rise in MBP. A speculative first look at a small sample of U.S. Hispanics suggests that MBP rates of recent immigrants tend to resemble those of Mexico, while MBP levels of migrants of long-term residence resemble the native-born U.S. populations. Conclusions. The findings underscore the need for definitive testing to confirm if Mexicans who relocate to the U.S. may acquire an acceleration of the renovasculopathies, and of the lifelong progression toward hypertension that this implies

Efectos del cloruro de sodio hiperosmolar intravenoso sobre el flujo sanguíneo de diversos órganos de la rata / Effects of hyperosmotic sodium chloride on blood flow of several organs of the rat

En ratas anestesiadas con uretano se estudió el efecto de la infusión endovenosa de cloruro de sodio hiperosmolar (CSH), al 10% 4 ml. kg-1, sobre hematocrito, presión arterial media y flujo sanguíneo en corteza renal, corteza cerebral, hígado y músculo esquelético. El flujo sanguíneo fue determinado con el método del clearance de hidrógeno de Auckland, efectuándose una determinación basal y otra a los 15 minutos de inyectado el CSH. Se calculó la resistencia vascular dividiendo la presión arterial por el flujo ssanguíneo. (Se consideró significativa una P < 0.05). El flujo sanguíneo aumentó significativamente por efecto del CSH en corteza cerebral, corteza renal e hígado, no detectándose modificaciones en el flujo sanguíneo del músculo esquelético. El CSH produjo aumento de presión arterial media en todos los grupos estudiados, excepto en el grupo en que se midió el flujo sanguíneo cortical cerebral. La resistencia vascular disminuyó en corteza cerebral e hígado, permaneciendo constante en corteza renal y músculo esquelético; en el grupo de animales vagotomizados la resistencia vascular en el músculo esquelético aumentó significativamente. El CSH produjo un descenso significativo del hematocrito. Los resultados obtenidos, salvo el observado en animales vagotomizados, son compatibles con los efectos descriptos por otros autores que emplearon CSH en experimentos con otras especies animales. También son compatibles con los efectos descriptos en seres humanos con el empleo de CSH en el tratamiento del shock hipovolémico refractario