Related Experiment Videos
Effects of microcystin-LR in isolated perfused rat kidney
A C Nobre1, M C Jorge, D B Menezes
1Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, CE, Brasil.
Abstract:
Microcystin is a hepatotoxic peptide which inhibits protein phosphatase types 1 and 2A. The objective of the present study was to evaluate the physiopathologic effects of microcystin-LR in isolated perfused rat kidney. Adult Wistar rats (N = 5) of both sexes (240-280 g) were utilized. Microcystin-LR (1 microg/ml) was perfused over a period of 120 min, during which samples of urine and perfusate were collected at 10-min intervals to determine the levels of inulin, sodium, potassium and osmolality. We observed a significant increase in urinary flow with a peak effect at 90 min (control (C) = 0.20 +/- 0.01 and treated (T) = 0.32 +/- 0.01 ml g-1 min-1, P<0.05). At 90 min there was a significant increase in perfusate pressure (C = 129.7 +/- 4.81 and T = 175.0 +/- 1.15 mmHg) and glomerular filtration rate (C = 0.66 +/- 0.07 and T = 1.10 +/- 0. 04 ml g-1 min-1) and there was a significant reduction in fractional sodium tubular transport at 120 min (C = 78.6 +/- 0.98 and T = 73.9 +/- 0.95%). Histopathologic analysis of the perfused kidneys showed protein material in the urinary space, suggestive of renal toxicity. These data demonstrate renal vascular, glomerular and urinary effects of microcystin-LR, indicating that microcystin acts directly on the kidney by probable inhibition of protein phosphatases.
Insights
Microcystin-LR, a toxin, significantly impacts kidney function by increasing urinary flow and glomerular filtration rate. This study reveals direct renal toxicity from microcystin-LR, affecting vascular, glomerular, and urinary systems.
Area of Science:
- Toxicology
- Nephrology
- Biochemistry
Background:
- Microcystins are potent hepatotoxins produced by cyanobacteria.
- These toxins inhibit protein phosphatase types 1 and 2A.
- The specific effects of microcystin-LR on kidney physiology are not fully understood.
Purpose of the Study:
- To evaluate the physiopathologic effects of microcystin-LR on the isolated perfused rat kidney.
- To investigate the direct impact of microcystin-LR on renal vascular, glomerular, and tubular functions.
Main Methods:
- Isolated perfused adult Wistar rat kidney model.
- Perfusion with microcystin-LR (1 microg/ml) for 120 minutes.
- Collection of urine and perfusate samples for analysis of inulin, sodium, potassium, and osmolality.
- Histopathologic examination of kidney tissue.
Main Results:
- Significant increase in urinary flow and glomerular filtration rate observed.
- Elevated perfusate pressure indicating renal vascular effects.
- Reduced fractional sodium tubular transport and presence of protein in urinary space, suggesting renal toxicity.
Conclusions:
- Microcystin-LR exerts direct detrimental effects on the kidney.
- The toxin impacts renal vascular, glomerular, and tubular functions.
- Probable inhibition of protein phosphatases by microcystin-LR contributes to observed renal toxicity.