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Renal involvement in leptospirosis: the effect of glycolipoprotein on renal water absorption.

Cesar KR, Romero EC, de Bragança AC, Blanco RM, Abreu PA, Magaldi AJ - PLoS ONE (2012)

Bottom Line: GLPc blocked Vp (200 pg/ml, n = 5) action, did not block cAMP (10(-4) M), and Forskolin (Fors--10(-9) M) action, but partially blocked Cholera Toxin (ChT--10(-9) M) action.GLP from L.biflexa serovar patoc (GLPp, non pathogenic, 250 µg) did not alter Vp action.In Group III, GLPc (250 µg) injected intraperitoneally produced a decrease of about 20% in IMCD Aquaporin 2 expression.

View Article: PubMed Central - PubMed

Affiliation: Basic Research Lab-LIM 12, Nephrology-HCFMUSP, São Paulo, São Paulo, Brazil.

ABSTRACT

Background: Leptospirotic renal lesions frequently produce a polyuric form of acute kidney injury with a urinary concentration defect. Our study investigated a possible effect of the glycolipoprotein, (GLPc) extracted from L. interrogans, on vasopressin (Vp) action in the guinea pig inner medullary collecting duct (IMCD).

Methods: The osmotic water permeability (Pf µm/s) was measured by the microperfusion in vitro technique. AQP2 protein abundance was determined by Western Blot. Three groups were established for study as follows: Group I, IMCD from normal (ngp, n = 5) and from leptospirotic guinea-pigs (lgp-infected with L. interrogans serovar Copenhageni, GLPc, n = 5); Group II, IMCD from normal guinea-pigs in the presence of GLPc (GLPc group, n = 54); Group III, IMCD from injected animals with GLPc ip (n = 8).

Results: In Group I, PFS were: ngp--61.8±22.1 and lgp--8.8±12.4, p<0.01 and the urinary osmolalities were: lgp--735±64 mOsm/Kg and ngp--1,632±120 mOsm/Kg. The lgp BUN was higher (176±36 mg%) than the ngp (56±9 mg%). In Group II, the Pf was measured under GLPc (250 µg/ml) applied directly to the bath solution of the microperfused normal guinea-pig IMCDs. GLPc blocked Vp (200 pg/ml, n = 5) action, did not block cAMP (10(-4) M), and Forskolin (Fors--10(-9) M) action, but partially blocked Cholera Toxin (ChT--10(-9) M) action. GLP from L.biflexa serovar patoc (GLPp, non pathogenic, 250 µg) did not alter Vp action. In Group III, GLPc (250 µg) injected intraperitoneally produced a decrease of about 20% in IMCD Aquaporin 2 expression.

Conclusion: The IMCD Pf decrease caused by GLP is evidence, at least in part, towards explaining the urinary concentrating incapacity observed in infected guinea-pigs.

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IMCD water permeability.Effects of GLPc (250 µg/ml) on: 2A - Vasopressin action (Vp, 200 pg/ml, n = 5), 2B - cAMP activity (10−5 M), 2C - Forskolin action (Fors 10−9 M, n = 5), 2D - Cholera Toxin action (ChT 10−9 M, n = 6), 2E - effect of GLPp on Vp action (GLPp- 250 µg/ml, n = 5). Values are expressed as mean ± SEM. Lines connect the averages of the data for each different period of the experiments. Significant differences: * p<0.02, **p<0.01. £ p<0.05, # p<0.001.
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pone-0037625-g002: IMCD water permeability.Effects of GLPc (250 µg/ml) on: 2A - Vasopressin action (Vp, 200 pg/ml, n = 5), 2B - cAMP activity (10−5 M), 2C - Forskolin action (Fors 10−9 M, n = 5), 2D - Cholera Toxin action (ChT 10−9 M, n = 6), 2E - effect of GLPp on Vp action (GLPp- 250 µg/ml, n = 5). Values are expressed as mean ± SEM. Lines connect the averages of the data for each different period of the experiments. Significant differences: * p<0.02, **p<0.01. £ p<0.05, # p<0.001.

Mentions: In these experiments the effect of GLPc on Vp ([Arg8] Vasopressin, 200 pg/ml) action was studied. First, GLPc was applied to the bath solution after Vp (n = 5) and then, in other experiments, the GLPc was added before the addition of Vp (n = 6). As the data showed, GLPc partially blocked the Vp-stimulated Pf when applied after Vp and practically blocked all the Vp action when applied before Vp. (Table 2, and Figure 2A).


Renal involvement in leptospirosis: the effect of glycolipoprotein on renal water absorption.

Cesar KR, Romero EC, de Bragança AC, Blanco RM, Abreu PA, Magaldi AJ - PLoS ONE (2012)

IMCD water permeability.Effects of GLPc (250 µg/ml) on: 2A - Vasopressin action (Vp, 200 pg/ml, n = 5), 2B - cAMP activity (10−5 M), 2C - Forskolin action (Fors 10−9 M, n = 5), 2D - Cholera Toxin action (ChT 10−9 M, n = 6), 2E - effect of GLPp on Vp action (GLPp- 250 µg/ml, n = 5). Values are expressed as mean ± SEM. Lines connect the averages of the data for each different period of the experiments. Significant differences: * p<0.02, **p<0.01. £ p<0.05, # p<0.001.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368910&req=5

pone-0037625-g002: IMCD water permeability.Effects of GLPc (250 µg/ml) on: 2A - Vasopressin action (Vp, 200 pg/ml, n = 5), 2B - cAMP activity (10−5 M), 2C - Forskolin action (Fors 10−9 M, n = 5), 2D - Cholera Toxin action (ChT 10−9 M, n = 6), 2E - effect of GLPp on Vp action (GLPp- 250 µg/ml, n = 5). Values are expressed as mean ± SEM. Lines connect the averages of the data for each different period of the experiments. Significant differences: * p<0.02, **p<0.01. £ p<0.05, # p<0.001.
Mentions: In these experiments the effect of GLPc on Vp ([Arg8] Vasopressin, 200 pg/ml) action was studied. First, GLPc was applied to the bath solution after Vp (n = 5) and then, in other experiments, the GLPc was added before the addition of Vp (n = 6). As the data showed, GLPc partially blocked the Vp-stimulated Pf when applied after Vp and practically blocked all the Vp action when applied before Vp. (Table 2, and Figure 2A).

Bottom Line: GLPc blocked Vp (200 pg/ml, n = 5) action, did not block cAMP (10(-4) M), and Forskolin (Fors--10(-9) M) action, but partially blocked Cholera Toxin (ChT--10(-9) M) action.GLP from L.biflexa serovar patoc (GLPp, non pathogenic, 250 µg) did not alter Vp action.In Group III, GLPc (250 µg) injected intraperitoneally produced a decrease of about 20% in IMCD Aquaporin 2 expression.

View Article: PubMed Central - PubMed

Affiliation: Basic Research Lab-LIM 12, Nephrology-HCFMUSP, São Paulo, São Paulo, Brazil.

ABSTRACT

Background: Leptospirotic renal lesions frequently produce a polyuric form of acute kidney injury with a urinary concentration defect. Our study investigated a possible effect of the glycolipoprotein, (GLPc) extracted from L. interrogans, on vasopressin (Vp) action in the guinea pig inner medullary collecting duct (IMCD).

Methods: The osmotic water permeability (Pf µm/s) was measured by the microperfusion in vitro technique. AQP2 protein abundance was determined by Western Blot. Three groups were established for study as follows: Group I, IMCD from normal (ngp, n = 5) and from leptospirotic guinea-pigs (lgp-infected with L. interrogans serovar Copenhageni, GLPc, n = 5); Group II, IMCD from normal guinea-pigs in the presence of GLPc (GLPc group, n = 54); Group III, IMCD from injected animals with GLPc ip (n = 8).

Results: In Group I, PFS were: ngp--61.8±22.1 and lgp--8.8±12.4, p<0.01 and the urinary osmolalities were: lgp--735±64 mOsm/Kg and ngp--1,632±120 mOsm/Kg. The lgp BUN was higher (176±36 mg%) than the ngp (56±9 mg%). In Group II, the Pf was measured under GLPc (250 µg/ml) applied directly to the bath solution of the microperfused normal guinea-pig IMCDs. GLPc blocked Vp (200 pg/ml, n = 5) action, did not block cAMP (10(-4) M), and Forskolin (Fors--10(-9) M) action, but partially blocked Cholera Toxin (ChT--10(-9) M) action. GLP from L.biflexa serovar patoc (GLPp, non pathogenic, 250 µg) did not alter Vp action. In Group III, GLPc (250 µg) injected intraperitoneally produced a decrease of about 20% in IMCD Aquaporin 2 expression.

Conclusion: The IMCD Pf decrease caused by GLP is evidence, at least in part, towards explaining the urinary concentrating incapacity observed in infected guinea-pigs.

Show MeSH
Related in: MedlinePlus