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1432a Arterioacleroals and Thrombosis Vol 11, No 5 Seprer8ber/ocrober 1991 .-V : t gene expression in cynomolgtu monkeys, that IL-1$ is ex- pressed in both early and advanced stagas of diet-indueed atherosclerosis, as well as in monkey monocytesJmacrophages, and suggest that this model can be employed to study the role of 1L-1S in atharogenesis. Extensf.e Oxidation of LDL Induces Particle At[re6atloa and Altered Maeroprtage Beoognitiba Henry F. Hoff, Todd E. Whitaker, and7une O'Neil Research /n.vinae, Cle+.eland Cfinic Fouedanon, Cleurlend,Ohio Although studies have reported structural and functional changes in LDL following oaidation:(ox-), none have described such changes with increasing degrees of ox. We describe time-dependent changes in chemical and structural eomposi- tion of ox-LDL and htrr they affect macrophage interaction.LDL (500 µg/ml) was incubated with 10:µM Clt" at20`C for up to 25 hr. Time-dependentincreases in conjugated'dienesd fluoroscence (36ckx/430em), and particle aggregation (aggr.) were found, the latter increasing with LDL concentration used: Similar degrees of LDL ox. gave fragments of apo B of the same size. Extensive LDL ox. induced aggr. of apa B, possibly'caused by covalent aou-linking of apo$. since apo B from aggr. ox-LDL but not from vonea-aggr. LDL was insol- ublc in SDS. Mildly ox-LDL cg. 8 hr in Cu' °(unaggr.) and the soluble portion of extensively ox-LDL (25 hr), were recognized by the scavenger receptor on mouse peritoneal maaophagee,. (inhibition of `1-oo-LDL macrophase degradation by aceryl LDL). By contract, neither accryl-LDL nor polyinosinic acid inhibited macrophage degradation of aggr. ox-LDL suggesting internalization by an alternate process. Thus, ox. of LDL leads to ditTerenu structural' and' functional I eharacteriatics- depend- ing on the degree of ox. Identiflcation of a Lipid-Fre.e Apo(al-Apo B Complex In the d> 2.2 Frsttion er Plasma Akira Yashiro, June O'Neil. and Henry F. Hoff Reseuxh /nsntutt Clevrfand Clinic foundaffon. ClttYland, Oliio Although studies have reported the binding of apo(a)-apo B complcxes eg.. 1a'1-B to different lipoprotein species. iden- t'iticsnon of lipid-free (a),B in plasma has not been reportcd; To identify such compicxes, we subjeaed! human plasma to denaitv gradient ultraccntrifugation and documented lmmu- norcactivc apo(a/ and apo B in the d> 1.2 fraction by appro- priate RIAs. Morerwer (a)-B was similar to delipidated Lp(a) in tr, agarose electroplinresis: On non-denaturing PAGE (S:S-7S % gradient), an MW of, l0'KD was found for the apu(ia)-B complex. On SDS-PAGE, one major band was found under non-reducing conditions which imrnunostained for both apo(a) and apo B. Under reducing conditions, two major bands were .een, one staining for apo(a) and one for apn B. (a)-B from the d> li2 plasma fraction bound and could he elutad'from a Scpharose-anti-apo(a) column. This fraction containing only apo(a)land apo B, was lipid flree, and mim- ici;e& d'elipidated Lp(a) by the above-describcd procedures. Thux, plasma contains a lipid-free apo(a)--apo B complex that could bind' under specific metabolic conditions to different lipoprotcin fractions. 5omatostatin and its Analogue. Angiopeptia. Inhibit Adhesion of Leukocytes to ttat Heart Endothellal Cells Dariusz Leazczynaki. Michael, D. Josephs.,Roben S. Fournier6 and Marie L. Foegh GeorFrraKr Unimrstrv Medlcal'Ctnttr. WashutRron, D:C.. The effect of somauxtatin (ST) andIts analogue Angiopep- tin (AP) on in tMrro adhesion of rat spleen Ieukocytes (LC) to uncumulated and IL-Ib stimulued rat hean endothelial eollt (EC) was studied. ST and AP inhibited LC adhesion to EC. The strnnttest inhibition was observed after 24 hours exposure. ti,. 1, iu ''S `1 t~ ~ Unstimutated EC bound 208x89 LCJmm'. Trcatment,wiih ST or AP (0.6-10 ALM)~ for 24h decreased btnding to 124_1:5 LC/t4tmt'and 11g=60, LCJirtm=. respectively (p<U.00!): EC stimulated for 4h with IL-lb (100U/m1) bound )„045=3'_ LC/ mm': ST (0.6 satyt) reduced' binding to 292x31 LGmm' (p<0.01). AP (1' µJvf)Iwas less potent and'reduced binding to 811s75 LGmm? (p<0.125). However, affect of AP was longer lasting (up to 24h). in conclusion. Angiopeptin may have a potential application in immune relatcd cardiac vascular dis- ease due to its prolonged inhibitory effect on IL-lb induced LC-EC adhesion. Plasma L/poproteins Specifically Bind Tbrombospondin ('CSP) Akihiko Muraishi: Maria A. Kowa)aka, Vicki~ R. Rothman, David M. Capuui, and George P. Tusrynskil Deparrment ojMedic,ne. Medlcal Collegc of Pennsvfvania. Phfl= adelphia, Pa. The present study' explored the potential I interaction be- tween TSP and plasma lipoproteins using an Ut virro binding assay, Human plasma lipoproteins VLDL, LDL HIDL and apolipoproteins Al and All were immobilized on microtitsr plates and TSP binding was deterrnined' tmmunochemcally with a polyclonal anti-TSP antibody. We found that human TSP bound: saturably to alli the plhsma lipoproteins tested. Binding was maximal in the presence of 1 mM Ca"!Mg` and was only, partlally inhibited'with 2 mM EDTA. RGD peptides had no effect on binding. In eorttraati TSP binding to fibrino- gen was completely ion dependent. The concentrations of TSP that produced half maximal binding for VLDL HDL LDL, apo Al. and apo All were 36.9, 1'24, 23.7; 6.9. and 18 nM. respectively. These dala demonstrate that TSP camspecifically interact with lipoproteins and suggest a potentia(!role for TSP in the metabolism of lipoproteins, in their deposition into the vessel walll and in atherogenesis. r The Aasociatibn Betwcen Carotid Artctial Wall Thickness and Acttve and Passive Cigarette Smoking George Howard. Moyes Szklo. Gregory, Evans„ Grethe Tell, John Eckfeldtl Gerardo Heiss, and the ARIC Investigators Bowman Cray School of Medicine, Winston Salem. N.C. The efiectof ciganette smoking on the carotid artery far wall tliickneu was considered in the white population, from the Atherosclerosis Risk in Communities (ARIC) study. The population was divided into 2,460 current smokers, 3,48 pasn smokcrs. 2,440 who never smoked but reported weekly cxpo• sure to environrnental cigarette smoke (ETS or "passive smoking"),,and 1.306 who never smoked with no exposure to ETS. Age proved to affect the differences between smoking status classes (ps0.0001); while gender had no effect (p>0:03). Within 5-year age groups there was a consistent gradient of wall' thickness across the smoking exposure cate• gories (rteanzS,E. in millimeters): Age group No. exposure ETS only Past smoker Current smoker i5-50 0,63_0.00h 0.66s0.0(]d 0.68zU.005 0.69x0.00h St-55 o.G8=o.0ok n.69sn.006 0.75z0.ooc, 0.77=o.ooft 5tA-6ti 0.7! s0.007' 0.74=0.006 0.82=0.008 0-84sU.UlU hl-ks 0.7720.011 o.78s0009 o.88x0.oa0 0.9U-0.015 Using analysis of covariance, differences between no exposure and ETS were significant only at younger ages (p<0.0001), while diflerences between ETS and past smoking, or between past and current smoking, were significantonlr'for older ages. This graded relationship underscores the importance of smok- inR as a risk factor for atherosclerosis.