Organ specific changes in the expression of cation-dependent and cation-independent

JOFRE G; BALMACEDA V; SARTOR T; CARVELLI L; BARRERA P; SOSA MA

CELLS TISSUES ORGANS

Karger

Año: 2009 vol. 190 p. 27 - 33

1422-6405

The co- existence of two mannose-6-phosphate receptors (MPRs) in most cell types remains still poorly understood. In this study, expression of the cation-dependent (CD-MPR) and the cation-independent (CI-MPR) MPR was measured by Western blot in rat organs at three ages; newborns, 10 and 90 day old rats.  It was observed that expression of CI-MPR tends to diminish from newborns to adults in five of the six organs sudied, whereas CD-MPR did not show a clear tendency along these ages.  In pancreas, instead, both MPRs increased progressively from newborns to adults.  Activity of two acid hydrolases was also measured at the ages studied and no direct correlation was found with expression of both MPRs. With the exception of pancreas, it is possible that CI-MPR is mostly occupied in the clearence of IGF-II at early steps of development and both MPRs participate later in maturation of the lysosomal apparatus.  We propose that in pancreas both receptors are involved in the increasing proteolitic activity of the exocrine gland during postnatal development.