Platelet secretion defect and impaired synthesis or response of thromboxane A2 in a patient with a bleeding disorder

28

Suppl . VI,

THROMBOSIS RESEARCH

1986

54 A;!IN A PATIXVT F%ATTm-rsEmI~DEFECrANDIMpmsyNltlEsIsm~oFTHRcNlBoxANE WITHA BLEEDING DISORDm.C. de Castellamau, M. Albors, J. 'Sol&, C. Cullat-& A. Tax&*, J.Fmm,M. Ll.FUtllant. BiawdicalReseaxhUnitmdHam&mlogyDept. kspitalSantPau.BatxelmaOEW5. Hospital General de El&e (Alicante)*, Spain. 'heplatelets of a 7years oldtxgwitha lifelcngbleedjng tendemy(Ivy@2min) shmed toACP,adremlineandsodiun mm-0lshapeckmgeandcmlyprimaryagregaU~inrespcxlse arachidmatehtdefectiveorabsentaggregaticm inreqxnse tohig?m-cmentraticrr;of Collagel, A-23187, ADPandarachidulate. Ristccetin (0.~l&ml) prcckxednarmal responses. Secreticnof 54$has iqairedandreleaseofplateletn~~leotideswasnonml. lheprqxsitusplatelets ~biteddefectivereleasereacti~andseccpldwave aggregkicn ~stimrlatedbyhigherconcentraticazsofarachidcp7ate~~~,a~A2 tit the defectwas reqcnsetoU4619 suggested (TWq) agcnist. lhe lackof platelet beycnd~~syntfietaselevel.Inadditionsupernatantfran~pati~~sPRp aftersth_&aticnbyarachicknate didnotaggregateaspirin~tedplatelets, but supernatantfrcmmnralpRppartidlly~~e(~~thepatiepltspRp. Yhmhmne +prcducticnmeaswedbyradi~,befaremdaftiseparaticplby H.P.L.C., in senm and during stimlaticn by PRPwithADP,Collagen or arachi&malx was iqkred withAW and Collagen, but it was nomal witharachicknate (1.6nM).Serun % wasless (85-ll5nghl)tkmincaltrals (280+1oong/ml). ?hesef~irrdicate~ttheTxA2defectinthispati~tresultfrcmapartial i2mkmam synthetase deficimcywtoanabrmmal TX+

55 ZINC INGESTION INCREASES PLATELET SENSITIVITY. Gerard flarx PhD and Matti Shaklai MD, Department Hematology, Beilinson Medical Center, Petah Tikva,

of Israel.

AS part of an ongoing study to delineate the influence of zinc on hemostatic processes (1,2), we examined the short-term effect of ingestion of zinc sulfate on platelet activity. In a limited number of in L/ivo experiments carried out to date, informed normal laboratory personel ingested 220 mg zinc sulfate, and blood samples were withdrawn hourly up to 4 hr. Plasma zinc levels more than tripled within 2-3 hrs after ingestion, then decreased to initial values. In a parallel manner, platelet sensitivity to stimulating agents (ADP, collagen and epinephrinel increased , then decreased to near initial levels. These preliminary findings suggest a physiologic correlation between zinc ingestion, plasma zinc levels and platelet sensitivity to metabolic activators.

1. Marx G and Eldor A., Amer. J. Henatol. l9, (1985). 2. Heyns du P A, Yarom R, Eldor A and Marx G. 213-219 (1985).

151-159 Blood,

66,