Release of human epidermal growth factor from platelets in accordance with aggregation in vitro.
We measured the intra-platelet content of human epidermal growth factor (hEGF) and beta-thromboglobulin (beta-TG) and the quantities of these released from platelets during in vitro aggregation. The intra-platelet amounts of hEGF and beta-TG in 10(8) platelets were 104.9 +/- 18.9 (Mean +/- SEM) pg and 2920.9 +/- 149.9 ng, respectively. During platelet aggregation elicited by 9, 11-epithio-11, 12-methano-thromboxane A2, a stable thromboxane A2 agonist, hEGF and beta-TG were released in amounts about 50% and 40% of the respective content in platelets. Also during arachidonate-induced aggregation, hEGF and beta-TG were released at about 60% and 50%, respectively. Various concentrations of thromboxane A2 antagonist, (9, 11), (11, 12)-di-deoxa-9, 11-dimethyl-methano-11, 12-methano-13, 14-dihydro-13-aza-14-oxo-15-cyclopentyl-16, 17, 18, 19, 20-pentanor-15-epi-thromboxane A2, suppressed both aggregation and release reactions in a dose-dependent manner. There were good correlations between the platelet aggregation rate and released beta-TG (r = 0.9368, p less than 0.01) or hEGF (r = 0.8931, p less than 0.01) and between released beta-TG and hEGF (r = 0.9385, p less than 0.01). These results suggest that hEGF is released from platelets in a similar fashion to beta-TG in vitro.
Nakamura
T
T
Department of Endocrinology, Dokkyo University School of Medicine, Tochigi, Japan.
Kasai
K
K
Banba
N
N
Ishikawa
M
M
Shimoda
S
S
D000328:Adult; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D001620:beta-Thromboglobulin / Q000378:metabolism
D001095:Arachidonic Acids; D010975:Platelet Aggregation Inhibitors; D001620:beta-Thromboglobulin; D016718:Arachidonic Acid; D013928:Thromboxane A2; D004815:Epidermal Growth Factor; C037866:STA 2; C049855:ONO 3708