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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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Leptospirotic guinea pig data.A- Urinary Volume (ml) and Urinary Osmolality (mOsm/Kg H2O). Dotted bar-UOsm; Open bar-UV. B- Water permeability. Pf µm/s. Values are expressed as mean ± SEM. Significant differences: * p<0.01; ** p<0.05.
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pone-0037625-g001: Leptospirotic guinea pig data.A- Urinary Volume (ml) and Urinary Osmolality (mOsm/Kg H2O). Dotted bar-UOsm; Open bar-UV. B- Water permeability. Pf µm/s. Values are expressed as mean ± SEM. Significant differences: * p<0.01; ** p<0.05.

Mentions: In the first group of experiments, normal guinea pigs (ngp, n = 5) were compared with the leptospirotic guinea pigs (lgp, n = 5). In the leptospiroric animals, the urinary volume (milliliters) and the BUN (mg %) were higher than the normal guinea pigs, but the urinary osmolality (mOsm/Kg) and the osmotic water permeability (Pf µm/s) were lower (Table 1, fig. 1A and 1B). These results evidenced that the infected guinea pigs presented urinary concentration incapacity and lower osmotic water permeability in comparison with normal guinea pigs.


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)

Leptospirotic guinea pig data.A- Urinary Volume (ml) and Urinary Osmolality (mOsm/Kg H2O). Dotted bar-UOsm; Open bar-UV. B- Water permeability. Pf µm/s. Values are expressed as mean ± SEM. Significant differences: * p<0.01; ** p<0.05.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0037625-g001: Leptospirotic guinea pig data.A- Urinary Volume (ml) and Urinary Osmolality (mOsm/Kg H2O). Dotted bar-UOsm; Open bar-UV. B- Water permeability. Pf µm/s. Values are expressed as mean ± SEM. Significant differences: * p<0.01; ** p<0.05.
Mentions: In the first group of experiments, normal guinea pigs (ngp, n = 5) were compared with the leptospirotic guinea pigs (lgp, n = 5). In the leptospiroric animals, the urinary volume (milliliters) and the BUN (mg %) were higher than the normal guinea pigs, but the urinary osmolality (mOsm/Kg) and the osmotic water permeability (Pf µm/s) were lower (Table 1, fig. 1A and 1B). These results evidenced that the infected guinea pigs presented urinary concentration incapacity and lower osmotic water permeability in comparison with normal guinea pigs.

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