The intrarenal arterial pattern in the generalized Shwartzman reaction

Shunting in renal microvasculature of the rat: a scanning electron microscopic study of corrosion casts

We reinvestigated the still controversial existence of arterial pathways by-passing glomeruli within kidneys of rats from weaning to more than 12 months old (i.e., body weight ranging from 39 g to 643 g). For this purpose, the arterial injection of microspheres 7.5 micrometer to 17 micrometer in diameter was combined to corrosion-replication of the arterial bed of a vasodilated perfused kidney preparation. This procedure allowed easy detection of arterial by-passes with light microscope and detailed observation with scanning electron microscope. Our results clearly demonstrate the existence of various categories of arterial by-passes throughout renal cortex regardless of age. Some of them had never been described before. These vascular by-passes were found with increased frequency from superficial to juxtamedullary cortex. In the latter area, frequency was not age-dependent, and approximately 10% (range 4-22%) of juxtamedullary glomeruli were involved. Data derived from previous microsphere studies would suggest that these structures are (partially) nonfunctioning in basal physiological conditions, but more information is needed to assess their possible functional role in the rat.

Spontaneous bilateral renal cortical necrosis in animals

Six cases representing three species, previously diagnosed as bilateral renal cortical necrosis (BCN), were studied histologically. One horse had vascular lesions including fibrinoid necrosis and fibrinous thrombi in various organs. Intrarenally these lesions occurred in interlobular arteries, afferent arterioles, and glomeruli. Another horse had bilateral renal glomerular thrombosis but no extra-glomerular vascular lesion. Distinct fibrinous deposition in the renal vessels did not occur among the other four cases. A comparison is drawn between the characteristic lesions in the generalized Shwartzman reaction (GSR) and BCN as diagnosed in our autopsy material. The renal alterations were compatible with GSR in two horses only among the six cases.