Role of Ca(2+) and protein kinase C in the serotonin (5-HT) transport in human platelets.
Cell Calcium
; 31(5): 235-44, 2002 May.
Article
en En
| MEDLINE
| ID: mdl-12098226
ABSTRACT
Accumulation of serotonin (5-HT) into human platelets was not affected by the presence of the extra-cellular calcium chelator EGTA, while decreased by platelet incubation with the membrane permeant chelator BAPTA-AM. Serotonin uptake also diminished upon platelet exposure to EGTA/thapsigargin or EGTA/ionomycin which increased the cytosolic [Ca(2+)] to levels lower than those inducing secretion of dense granules. The latter inhibition depended in part on changes of intra-granular pH, since the accumulation of acridine orange, which is driven into the dense granules by the intra-granular acid pH gradient, was slightly decreased in the presence of EGTA/thapsigargin. These compounds also inhibited the 5-HT uptake in platelets pre-incubated with reserpine and bafilomycin that prevent 5-HT from entering into the dense granules. Inhibitors of protease, protein phosphatase, Na(+)/H(+) exchanger or ciclo-oxygenase activities did not modify the serotonin accumulation. Addition of EGTA/thapsigargin to reserpine-treated, [(14)C]5-HT-loaded, platelets caused an imipramine-insensitive release of labelled serotonin. This release was reduced by both BAPTA-AM or protein kinase C inhibitor bisindoylmaleimide (GF). The latter compound, either alone or together with EGTA/thapsigargin, inhibited the 5-HT accumulation in reserpine-treated platelets. It is concluded that both cytosolic [Ca(2+)] and protein kinase C are involved in the regulation of the plasma membrane 5-HT transport.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Plaquetas
/
Proteína Quinasa C
/
Proteínas Portadoras
/
Serotonina
/
Membrana Celular
/
Calcio
Límite:
Humans
Idioma:
En
Revista:
Cell Calcium
Año:
2002
Tipo del documento:
Article
País de afiliación:
Italia