1 Polymorphonuclear leukocytes (PMN) may contribute to the pathogenesis of acute coronary heart disease (CHD). 2 Epidemiological and laboratory evidence suggests that red wine, by virtue of its polyphenolic constituents, may be more eective than other alcoholic beverages in reducing the risk of CHD mortality. 3 The aim of the present study was to investigate the eects of trans-resveratrol (3,4',5-trihydroxytrans-stilbene), a polyphenol present in most red wines, on functional and biochemical responses of PMN, upon in vitro activation. 4 trans-Resveratrol exerted a strong inhibitory eect on reactive oxygen species produced by PMN stimulated with 1 mM formyl methionyl leucyl phenylalamine (fMLP) (IC 50 1.3+0.13 mM, mean+ s.e.mean), as evaluated by luminol-ampli®ed chemiluminescence. 5 trans-Resveratrol prevented the release of elastase and b-glucuronidase by PMN stimulated with the receptor agonists fMLP (1 mM, IC 50 18.4+1.8 and 31+1.8 mM), and C5a (0.1 mM, IC 50 41.6+3.5 and 42+8.3 mM), and also inhibited elastase and b-glucuronidase secretion (IC 50 37.7+7 and 25.4+2.2 mM) and production of 5-lipoxygenase metabolites leukotriene B 4 (LTB 4 ), 6-trans-LTB 4 and 12-trans-epi-LTB 4 (IC 50 48+7 mM) by PMN stimulated with the calcium ionophore A23187 (5 mM). 6 trans-Resveratrol signi®cantly reduced the expression and activation of the b 2 integrin MAC-1 on PMN surface following stimulation, as revealed by FACS analysis of the binding of an anti-MAC-1 monoclonal antibody (MoAb) and of the CBRM1/5 MoAb, recognizing an activation-dependent epitope on MAC-1. Consistently, PMN homotypic aggregation and formation of mixed cell-conjugates between PMN and thrombin-stimulated ®xed platelets in a dynamic system were also prevented by transresveratrol. 7 These results, indicating that trans-resveratrol interferes with the release of in¯ammatory mediators by activated PMN and down-regulates adhesion-dependent thrombogenic PMN functions, may provide some biological plausibility to the protective eect of red wine consumption against CHD.

SummaryIn PMN/platelet suspensions stimulated by fMLP giant mixed aggregates are formed and TxB2 and LTC4 are synthesized as the result of the cooperation in the arachidonic acid (AA) metabolism during cell/cell contact. PMN-derived cathepsin G induced the expression of P-selectin on platelet surface. GE12, an antibody against P-selectin, significantly reduced mixed cell aggregates. GE12 did not affect platelet aggregation induced by PMN-derived supernatants, indicating that the inhibitory effect of GE12 on mixed cell aggregation depends on inhibition of PMN/platelet adhesion. GE12 significantly reduced TxB2 and LTC4 production in PMN/platelet mixed cell suspensions stimulated by fMLP. As previously reported, synthesis of 3H-TxB2 in 3H-AA-labeled PMN/unlabeled platelets indicates that platelets utilize 3H-AA from PMN. 3H-LTC4 production in unlabeled PMN/3H-AA-labeled platelets indicates that bidirectional routes are utilized in this system for LTC4 synthesis. GE12 significantly reduced 3H-TxB2 and 3H-LTC4 synthesis. These results show that cathepsin G released by activated PMN induces the expression of P-selectin on platelet membrane: this adhesive glycoprotein modulates cell-cell contact and transcellular metabolism of AA.

Human polymorphonuclear leukocytes (PMN) activated by n-formyl- methionyl-leucyl-phenylalanine (fMLP), in the presence of cytochalasin B, are able to induce activation of coincubated autologous platelets “via” cathepsin G released from the azurophilic granules. However, thromboxane (Tx) B2 production in this system cannot be completely explained by cathepsin G-stimulated platelet arachidonate metabolism. Indeed, the amount of TxB2 found in supernatants of platelet/PMN suspensions challenged with 1 mumol/L fMLP was twofold to fourfold higher than that measured when platelets were stimulated by supernatants from fMLP-activated PMN. In the present report, we analyzed the possibility that PMN-induced TxB2 production in this system is the result of transcellular metabolism of arachidonic acid (AA) between fMLP-activated PMN and cathepsin G-stimulated platelets. 3H-AA-labeled PMN were used to test if a transfer of AA or metabolite(s) occur from PMN to platelets. Our results showed that: (1) 3H-TxB2 and 3H-12-HHT are synthesized when 3H-AA-labeled PMN are activated mixed to unlabeled platelets; (2) total radioactivity released by fMLP-stimulated PMN is increased in the presence of platelets, whereas the membrane content of unesterified 3H-AA is reduced; (3) platelet cyclooxygenase inhibition completely prevents 3H- TxB2 synthesis; and (4) inhibition of cathepsin G-induced platelet activation with the antiprotease eglin C blocks the formation of 3H- TxB2. These data show that in the experimental system used, platelets use PMN-derived unmetabolized AA to synthesize TxB2.

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The successful treatment with thiopental (10 mg/kg, i.v.) of 9 severely asphyxiated newborns, under artificial ventilation, with neonatal seizures resistant to phénobarbital, is reported in this pilot study. The clinical and electroencephalogram control of seizures was prompt and resolute. No adverse effect on cardiovascular function (heart rate, blood pressure) was observed. The terminal half-life of thiopental averaged 9 h, the total plasma clearance 0.20 l/h/kg, and the steady-state volume of distribution 3.6 l/h/kg. The kinetic profile of the drug compared to phenobarbital and phenytoin in newborns suggests that its action is quicker and shorter lasting. Thus, from these findings, thiopental may offer a useful and handy approach for the safe and effective treatment of phenobarbital-resistant neonatal seizures.

The pharmacokinetic and pharmacodynamic profiles of atenolol were studied in adult male rabbits on continuous peritoneal dialysis given 3 mg/kg i.v. before and during renal failure. The average terminal elimination half-life for the drug was 2.5 h calculated from blood, dialysate or urinary data. This value increased about nine times in anuric conditions. Although atenolol was eliminated in the peritoneal fluid, the amount excreted was relatively low both in normal conditions and renal failure, respectively 0.6 and 7% of the administered dose. The pharmacokinetic model was extended by an "effect compartment", which has no influence on the predetermined mass of drug in the body, to analyse the relationship between heart rate fall and changes in atenolol blood concentrations. After drug administration, heart rate fell rapidly about 90 beats in both states. The mean equilibration half-time of atenolol effect and blood concentrations was 0.7 and 1.5 h in normal and pathological states, respectively. The mean blood concentration required to produce 50% of heart rate fall was similar in both conditions, 0.23 mg/l. The nine-fold decrease of atenolol elimination in anuria was in good agreement with the increase in duration of the drug's effect, and was suitably described by the "effect model".

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