Platelet aggregation may not be a prerequisite for collagen-stimulated platelet generation of nitric oxide

By determining the sum of the supernatant concentrations of nitrite and nitrate the stimulated generation of nitric oxide (NO) by human washed platelets induced by a range of fibrillar collagen concentrations (0.0156-25 microg ml(-1)) was investigated. Platelet serotonin (5-hydroxytryptamine, 5-HT) efflux and platelet aggregation were also measured. Under resting conditions (0 microg ml(-1) collagen) platelet NO release was equivalent to 1.06+/-0.17 nmol per 10(8) platelets. Maximal NO release, equivalent to 2.1+/-0. 37 nmol per 10(8) platelets, was observed with only 0.0625 microg ml(-1) collagen (P<0.02, stimulated vs. resting release), higher collagen concentrations producing no further increases in platelet NO output. By contrast, maximal platelet aggregation and 5-HT efflux did not occur until collagen concentrations of 2.5 microg ml(-1) and 10-25 microg ml-1), respectively, had been achieved. L-NAME (1 mmol l(-1)) and L-NMMA (1 mmol l(-1)) inhibited stimulated platelet NO generation by 78+/-6% and 72%, respectively. Contrasting with fibrillar collagen, fibrillar beta-amyloid protein had no effect on platelet NO generation, or on 5-HT efflux or aggregation. These data perhaps indicate that NO generation by human platelets is stimulated by concentrations of fibrillar collagen insufficient to elicit an aggregatory response. Such a mechanism could operate in vivo to inhibit platelet aggregation which might otherwise be induced by low concentrations of circulating agonists.

Medienart:

Artikel

Erscheinungsjahr:

1999

Erschienen:

1999

Enthalten in:

Zur Gesamtaufnahme - volume:1473

Enthalten in:

Biochimica et biophysica acta - 1473(1999), 2-3 vom: 27. Dez., Seite 286-92

Sprache:

Englisch

Beteiligte Personen:

Smith, C C [VerfasserIn]
Stanyer, L [VerfasserIn]
Cooper, M B [VerfasserIn]
Betteridge, D J [VerfasserIn]

Themen:

31C4KY9ESH
333DO1RDJY
9007-34-5
Collagen
Enzyme Inhibitors
Journal Article
NG-Nitroarginine Methyl Ester
Nitric Oxide
Serotonin
V55S2QJN2X

Anmerkungen:

Date Completed 14.02.2000

Date Revised 10.06.2019

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM105241601