THROMBOSIS RESEARCH 37; 343-346, 1985 0049-3848/85 $3.00 + .OO Printed in the USA. Copyright (c) 1985 Pergamon Press Ltd. All rights reserved. BRIEF COMMUNICATION CIGARETTE SMOKING DOES NOT AFFECT PG12 PLATELET RECEPTORS Pietro A. Modesti, Albert0 Fortini, Rosanna Abbate, and Gian F. Gensini Clinica Medica I, University of Florence Florence, Italy (Received 30.7.1984; Accepted in revised form 20.10.1984 by Editor G. De Gatano) INTRODUCTION Cigarette smoking was shown to enhance platelet adhesiveness (1,2) and aggregability (3,4), and to shorten the bleeding time (5); these effects on platelet function are most likely due to multiple factors such as the increased catecholamine plasma levels, observed in the immediate post-smoking period (61, or the increased NEFA plasma concentration(7).Moreover a decreased prostacyclin formation (8,9) and a decreased platelet sensiti- vity to PGI,(lO,ll) have been recently reported to occur ir: smokers; Sinzinger (11) has also reported that exposure of non- smokers to smoke for some days induces a decrease in baseline (prior t:o smoking) platelet sensitivity to PG12. This change in platelet sensitivity to PG12 could be related to a change in PG12 platelet binding sites. The aim of this investigation was to study the effect of smokiv? habits on PG12 p latelet binding sites. MATERIALS AND METHODS Nine healthy volunteers were investigated. They were divided in two groups: the first was composed of 5 non-smokers (4 males and 1 female), 23 to 36 years old (28.6+5; meantSD) and the second one by 4 smokers (2 males and 2 females,l5-70 cigarettes daily for at least 5 years) aged 24 to 28 (26t1.8; mean+SD). All the subjects were free from cardiovascular disease, diabe- tes, hypertension, hyperthyroidism, or other disease which could jeopardize the prognosis in the following 5 years; moreover they had not taken any drug for at least 15 days.Blood Key words: Prostacyclin, receptor, smoke, platelet. 343