2-methyl-3-(4-(3-pyridinylmethyl)phenyl)-2-propenoic-acid and Glomerulosclerosis--Focal-Segmental

Administration of heparin to rats with 1 3/4 nephrectomy prevents the development of glomerulosclerosis, hypertension and retards the decrease in renal function seen in these rats. To further define the role of hypertension and/or coagulation in the pathogenesis of the glomerulopathy seen in this model we studied several groups of rats with 1 3/4 nephrectomy: (1) a control group; (2) a group receiving a 'high dose' of acetylsalicylic acid (50 mg/kg) plus dipyridamole (10 mg/kg); (3) a group receiving a 'low' dose (5 mg/kg body weight) of acetylsalicylic acid alone; (4) a group receiving OKY 1581, an inhibitor of thromboxane synthesis; (5) a group treated with antihypertensive medications; (6) a group receiving heparin subcutaneously twice daily, and (7) a group given oral Coumadin. Drugs in all groups were administered daily for 4 weeks. All treated groups had a decrease in blood pressure (BP), in the ratio of heart weight to body weight, in BUN levels and had fewer abnormal glomeruli. The effects of acetylsalicylic acid alone, of acetylsalicylic acid plus dipyridamole, and OKY 1581 may be due to inhibition of platelet aggregation and intraglomerular thrombosis, with the fall in BP being the consequence of improved renal function. On the other hand, the decrease in BP may be related to a primary effect of these drugs. The lower BP in turn may play a role in slowing the progression of renal disease and improving the renal histology in the treated groups.

Topics: Animals; Anticoagulants; Antihypertensive Agents; Blood Urea Nitrogen; Female; Glomerulonephritis; Glomerulosclerosis, Focal Segmental; Hypertension, Renal; Methacrylates; Nephrectomy; Platelet Aggregation Inhibitors; Rats; Rats, Inbred Strains; Thromboxane-A Synthase

Ablation of greater than 70% of renal mass in the rat results in hypertension, proteinuria, and glomerular sclerosis of the remnant kidney. Rats with a remnant kidney have increased excretion of thromboxane in the urine when compared with normal rats. Chronic oral administration of OKY 1581, an inhibitor of thromboxane synthesis, in rats with a remnant kidney increases renal blood flow and glomerular filtration rate (GFR), decreases protein and thromboxane excretion in the urine, lowers blood pressure and cardiac index, and improves renal histology. The degree of hypertrophy of the remnant kidney was unaffected by administration of OKY 1581. Calculated values for single nephron plasma flow and GFR were significantly greater in rats with remnant kidneys given OKY 1581 than in rats given saline. Acute i.v. administration of OKY 1581 increased renal plasma flow and GFR in rats with a remnant kidney but not in normal rats or rats with a remnant kidney previously treated with acetylsalicyclic acid. OKY 1581 markedly inhibited platelet aggregation. We suggest that in this model of renal disease platelet aggregation and intraglomerular thrombosis play a key role in the development of glomerulosclerosis. Inhibition of platelet aggregation prevents development of glomerulosclerosis, hypertension, and cardiac hypertrophy. We suggest that hyperperfusion and hyperfiltration per se occurring in remnant glomeruli are not directly responsible for the development of glomerulosclerosis.

Topics: Acrylates; Animals; Blood Pressure; Disease Models, Animal; Female; Glomerular Filtration Rate; Glomerulosclerosis, Focal Segmental; Heart; Kidney; Kidney Diseases; Methacrylates; Nephrectomy; Oxidoreductases; Platelet Aggregation; Rats; Thromboxane B2; Thromboxane-A Synthase