Increased hyaline droplet formation in male rats exposed to decalin is dependent on the presence of alpha 2u-globulin.

A peculiar decalin-induced male rat nephropathy associated with the altered renal handling of filtered protein appears limited to the accumulation of the protein, alpha 2u-globulin. Several strains of male rats that produce alpha 2u-globulin (Fischer-344, Sprague-Dawley, Buffalo, and Norway Brown) demonstrate spontaneous renal cortical hyaline droplets which are exacerbated after exposure to decalin. In all cases, a close correlation exists between hyaline droplet formation observed histologically and alpha 2u-globulin accumulation measured biochemically. In stark contrast, the NCI-Black-Reiter strain, which does not produce measurable quantities of alpha 2u-globulin, neither forms hyaline droplets nor accumulates any filtered protein in its kidney cortex either spontaneously or after exposure to decalin. Also, female rats injected ip with male rat alpha 2u-globulin exhibit increased hyaline droplet formation and alpha 2u-globulin accumulation when treated with decalin. These data provide evidence that the presence of alpha 2u-globulin is key in understanding why this nephropathy appears unique to the male rat.