INVESTIGADORES
ROSSI Juan Pablo Francisco
artículos
Título:
Expression and cellular distribution pattern of plasma membrane calcium pump isoforms in rat pancreatic islets
Autor/es:
GARCIA, M,E.; DEL ZOTTO, H.; CARIDE, A.J.; PENNISTON, J.T.; ROSSI, J.P.F.C.; GAGLIARDINO, J.J.
Revista:
JOURNAL OF MEMBRANE BIOLOGY
Editorial:
Springer Verlag
Referencias:
Lugar: New York; Año: 2002 p. 17 - 23
ISSN:
0022-2631
Resumen:
This work is aimed at identifying the presence and cellular
distribution pattern of plasma membrane calcium pump (PMCA) isoforms in
normal rat pancreatic islet. Microsomal fractions of isolated islets
and exocrine tissue were analyzed to detect different PMCA isoforms.
The cellular distribution pattern of these PMCAs in the islets was also
studied in fixed pancreas sections incubated with antibodies against
PMCAs and insulin. Antibody 5F10, which reacts with all PMCA variants,
showed multiple bands in the blots in the 127-134 kDa region,
indicating the presence of several isoforms. Microsomes also reacted
positively with specific antibodies for individual PMCA isoforms,
generating a band of the expected size. Antibody 5F10
immunocytochemically labeled the plasma cell membrane of both b- and
non-b-cells, but predominantly the former. All islet cells were also
labeled with antibodies against isoforms 1 and 4, while the antibody
reacting with isoform 3 labeled exclusively b-cells. A few b- and
non-b-cells were positively labeled with the antibody reacting with
PMCA b variant. Negative results were obtained with the antibody
against isoform 2. Further studies, together with previous reports on
the modulatory effect of insulin secretagogues and blockers upon PMCA
activity, may provide evidence of the importance of this particular
PMCA expression for islet function under normal and pathological
conditions.