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

Lugar: Suiza; Año: 2008 vol. 190 p. 27 - 33

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, and 10 and 90 day old rats.  It was observed that expression of the CI-MPR tends to diminish from newborns to adults in five of the six organs studied, whereas the CD-MPR did not show a clear tendency over these ages.  In pancreas, conversely, both MPRs increased progressively from newborns to adults.  Activity of two acid hydrolases was also measured at the ages studied and a low correlation was found with the expression of the two MPRs. With the exception of the pancreas, it is possible that the CI-MPR is mostly occupied with the clearence of IGF-II at early stages of development, and that later both MPRs may participate in the maturation of the lysosomal apparatus. We propose that in the pancreas both receptors may be involved in the increasing proteolytic activity of this exocrine gland during postnatal development.