Vet. Res. 34 (2003) 137-151
DOI: 10.1051/vetres:2002061

SDS-PAGE and Western blot of urinary proteins in dogs with leishmaniasis

Concepción Zaragoza^a, Rafael Barrera^a, Francisco Centeno^b, Jose A. Tapia^c, Esther Durán^a, Marta González^d and M. Cinta Mañé<sup>a

a</sup>  Departamento de Medicina y Sanidad Animal, Facultad de Veterinaria, Universidad de Extremadura, Avda. Universidad s/n, 10004 Cáceres, Spain
^b  Departamento de Bioquímica, Biología Molecular y Genética, Facultad de Veterinaria, Universidad de Extremadura, Avda Universidad s/n, 10004 Cáceres, Spain
^c  Digestive Diseases Branch, NIDDK/NIH, Bethesda, MD, USA
^d  Departamento de Patología Animal II, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain

(Received 21 February 2002; accepted 23 September 2002)

Abstract
Canine leishmaniasis is an endemic disease in the Mediterranean area caused by the protozoan Leishmania infantum, which usually produces renal failure. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot using antibodies to IgG and IgA from dogs were carried out in the urine of 22 dogs with leishmaniasis diagnosed by ELISA and confirmed by PCR, and 20 healthy dogs. The results were compared to renal function laboratory tests and to those from a histopathological study of the kidneys from sick animals that died naturally or were euthanized. Five different bands with molecular weights ranging from 10 to 110 kDa were obtained from the electrophoresis of the urine of healthy dogs. 33.5% of total proteins corresponded to low molecular weight proteins and the other proteins had middle and high molecular weights. However, in the group with leishmaniasis, a maximum of 11 different bands with molecular weights ranging from 10 kDa to 150 kDa were displayed in the electrophoresis of the urine. The urine electrophoretic pattern in the sick dogs was classified as mixed (proteins with high and low molecular weights) because low molecular weight proteins made up 57.9% and the rest of the proteins had middle and high molecular weights. In Western blot, none of the healthy dogs showed excretion of IgG and/or IgA, whereas IgG and IgA were detected in the Western blot of urine of 68% and 55% respectively of dogs with leishmaniasis. The results obtained in the leishmaniasis group agreed with glomerular and tubular damage, which were confirmed by the histopathological findings.

Key words: leishmaniasis / proteinuria / dog / SDS-PAGE / Western blot

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