Pharmacokinetics of trans-resveratrol in its aglycone (RES AGL )and glucuronide (RES GLU ) forms were studied following intravenous (15 mg/kg i.v.) and oral (50 mg/kg p.o.) administration of trans-resveratrol in a solution of ␤-cyclodextrin to intact rats. In addition, the enterohepatic recirculation of RES AGL and RES GLU was assessed in a linked-rat model. Multiple plasma and urine samples were collected and concentrations of RE-S AGL and RES GLU were determined using an electrospray ionization-liquid chromatography/tandem mass spectrometry method. After i.v. administration, plasma concentrations of RE-S AGL declined with a rapid elimination half-life (T 1/2 , 0.13 h), followed by sudden increases in plasma concentrations 4 to 8 h after drug administration. These plasma concentrations resulted in a significant prolongation of the terminal elimination half-life of RES AGL (T 1/2TER , 1.31 h). RES AGL and RES GLU also displayed sudden increases in plasma concentrations 4 to 8 h after oral administration, with T 1/2TER of 1.48 and 1.58 h, respectively. RES AGL bioavailability was 38% and its exposure was approximately 46-fold lower than that of RES GLU (AUC inf , 7.1 versus 324.7 mol⅐ h/l). Enterohepatic recirculation was confirmed in the linked-rat model since significant plasma concentrations of RES AGL and RES GLU were observed in bilerecipient rats at 4 to 8 h. The percentages of the exposures of RES AGL and RES GLU that were due to enterohepatic recirculation were 24.7 and 24.0%, respectively. The fraction of drug excreted in the urine over a period of 12 h was negligible. These results confirm that RES AGL is bioavailable and undergoes extensive first-pass glucuronidation, and that enterohepatic recirculation contributes significantly to the exposure of RES AGL and RES GLU in rats.Interest in the study of phenolic compounds present in red wine has grown since epidemiological studies have shown an inverse correlation between red wine consumption and the incidence of cardiovascular diseases (Nanji and French, 1986;Hegsted and Ausman, 1988). Resveratrol (3,5,4Ј-trihydroxystilbene), a molecule from the viniferin family of polymers, was identified as a biologically active compound in red wine in 1992 (Siemann and Creasy, 1992). Since then, numerous in vivo and in vitro studies have assessed the ability of resveratrol in preventing multiple pathophysiological processes. Resveratrol has the ability to inhibit the peroxidation of lipid membranes (Fauconneau et al., 1997), to decrease the concentration of low-and very-low-density lipoproteins (Frankel et al., 1993), and to inhibit platelet aggregation (Kimura et al., 1985), three conditions that help prevent cardiovascular diseases. Although significant estrogenic-like activity of resveratrol has been demonstrated in vitro (Gehm et al., 1997;Bhat et al., 2001), this was not proven in vivo in rats (Turner et al., 1999). Finally, trans-resveratrol was shown to have cancer chemoprotective properties and to induce apoptosis in leukemia and human breast carcinom...

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Metabolite profiling is one of the most challenging fields in applied mass spectrometry. Mass spectrometry was used to characterize the metabolites of propranolol, a β‐adrenergic receptor antagonist containing numerous oxidation sites. Propranolol is extensively metabolized, with most metabolites appearing in urine. Urine samples were collected from young adult male Sprague–Dawley rats. Structural identification of various metabolites was performed by LC/MS/MS, using a PE SCIEX triple quadrupole instrument (PE SCIEX API 3000). Metabolites were itemized using several LC/MS/MS techniques, including Q3 full scan and precursor and constant neutral loss experiments. A looped experiment technique revealed the presence of mono‐ and di‐hydroxylated metabolites as well as regio isomers of hydroxy‐ and dihydroxy‐propranolol glucuronides and propranolol glucuronic acid. Propranolol glucuronide was not observed, while the presence of dealkylated metabolites was suggested but not confirmed. Copyright © 1999 John Wiley & Sons, Ltd.

The aphid Rhopalosiphum padi (L.) coexists with the leafhopper Psammotettix alienus (Dahlbom) in the same cereal crops. However, dense populations of the aphid were never observed to be associated with dense populations of the leafhopper. This laboratory study focuses on the effect of the aphid at various densities on the development and reproductive biology of the leafhopper and constitutes a preliminary test to understand the interactions between these insects in the field. Independently of food quantity, an increase in aphid numbers caused a lengthening of development duration and increased mortality of leafhopper nymphs. In the absence of aphids, leafhopper nymphs preferred to feed on the lower part of the plant. In the presence of aphids, the leafhoppers moved towards the upper part of the plant. An increase in aphid numbers had no significant influence on the longevity of leafhopper females, although the daily fecundity decreased significantly. These data demonstrate the negative effect of R. padi on the development and fecundity of P. alienus and corroborated the field observations. Because food quantity was not the limiting factor, further experiments are underway to elucidate the factors modifying leafhopper biology. Such factors could be used to manipulate leafhopper populations.

The Canadian Entomologist 128: 199-207 (1996) Attack and emergence of the engraver beetles Ipspini Say and I. latidens LeConte were measured in lodgepole pine (Pinus contorta var. latifolia Engelm.) naturally attacked by the mountain pine beetle, Dendroctonusponderosae Hopk., in 1991. Sample trees were baited with the Ips pheromones ipsdienol and lanierone 1 week and 3 weeks after attack by the mountain pine beetle and again the following spring to observe the effects of the timing of bait placement. The densities of attack, egg gallery length, emergence, and hibernation of Ips species were measured. Ips latidens did not attack either the baited or unbaited trees at breast height until the spring of 1992 and the relatively low emergence was not significantly different by treatments. Among the 1991 treatments, the densities at breast height (1.3 m) of I. pini attack, egg gallery length, adult emergence in the fall of 1991, and numbers of hibernating adults in the duff were all highest for the 3-week treatment and lowest for the unbaited treatment. Significantly higher densities of beetles emerged and hibernated in the duff on the north sides of trees. Ipspini emergence in late summer 1992 from trees additionally baited in spring 1992 was significantly higher than for trees baited only in fall 1991. The density and temporal distribution of the emergence of both Ips species is discussed in relation to that of the mountain pine beetle. Safranyik, L., T.L. Shore et D.A. Linton. 1996. Augmentation des infestation et de la densite des couvees d'lps pini Say (Coleoptera: Scolytidae) aprks traitement i l'ipsdiknol et i la lanierone dans des pins vrilles deji infest& par le Dendroctone du pin ponderosa. The Canadian Entomologist 128: 199-207. THE CANADIAN ENTOMOLOGIST March/April1996