Ochratoxicosis in Beagle Dogs

Three young male Beagle dogs were given daily oral doses of 0.3 mg/kg body weight of crystalline ochratoxin A. Three untreated Beagle dogs served as controls. The principals survived for 11–15 days and were killed. Cytomorphologic alterations were seen primarily in the endomembrane system of the renal epithelial cells of the proximal convoluted tubules. Increased amounts of smooth-surfaced membranes were present as linear and concentric arrays and as large and small vesicles in many proximal tubular epithelial cells. Few basilar infoldings of the plasma membrane were present in proximal tubular epithelial cells of the principals, but extracellular basilar labyrinth was extensive in proximal tubular epithelial cells of the control kidney. Many tubular epithelial cells contained lipid droplets and cytoplasmic accumulations of phospholipids. The mitochondria usually appeared normal. Prominent ultrastructural alterations of the interstitium included separation between tubular basement membranes, increase in the number of interstitial cells, well-developed secretory apparatuses in many interstitial cells, and the presence of collagen and amorphous material. Few alterations were found in the epithelial cells of the distal convoluted tubules, but some contained more lipid droplets than normally. No consistent alterations were found in other parts of the nephron.