Abstract:
Intermediate filaments belong to a large family
of proteins which contribute to the formation of
the cytoskeleton. The immunolocalization of
cytoskeletal proteins has been used extensively
in the diagnosis of various renal pathologies. The
present study described the immunolocalization
of the cytoskeletal proteins vimentin, desmin,
smooth muscle actin, and cytokeratin 19 in the
normal kidney of the dromedary camel. Kidney
samples from eight adult camels were processed
for histology and immunohistochemistry. The
kidney was enclosed in a renal capsule composed
of vimentin immunoreactive fibroblasts and
smooth muscle actin immunoreactive smooth
muscle cells. The smooth muscle cells in the renal
capsule did not exhibit desmin immunoreactivity.
Podocytes forming the visceral layer of the
glomerular capsule were immunoreactive for
vimentin. Immunoreactivity for vimentin and
smooth muscle actin in the parietal layer of the
glomerular capsule varied, with both reactive
and non-reactive cells observed. Intraglomerular
mesangial cells were immunoreactive for smooth
muscle actin and desmin, but non-reactive to
vimentin. The endothelial lining of blood vessels
was vimentin immunoreactive, while smooth
muscle actin and desmin were demonstrated in
the smooth muscle cells of the vessels. The thin
limbs of the loops of Henle in cortical nephrons
displayed vimentin immunoreactivity. The
proximal and distal convoluted tubules, as well
as the collecting ducts were negative to vimentin,
smooth muscle actin, desmin and cytokeratin 19
immunostaining. In conclusion, the present study
has revealed that similarities and differences exist
in the immunolocalization of cytoskeletal proteins
in the camel when compared to other mammals.
The presence of smooth muscle actin in the
parietal cells of the glomerular capsule suggests
a contractile function of these cells. The results
of the study indicate that vimentin and smooth
muscle actin can be used as markers for the
identification of podocytes and intraglomerular
mesangial cells, respectively, in the camel kidney.
