The current study examined whether adolescent rats are more vulnerable than adult rats to the lasting adverse effects of cannabinoid exposure on brain and behavior. Male Wistar rats were repeatedly exposed to D-9-tetrahydrocannabinol (D 9 -THC, 5 mg/kg i.p.) in a place-conditioning paradigm during either the adolescent (post-natal day 28 + ) or adult (post-natal day 60 + ) developmental stages. Adult rats avoided a D 9 -THC-paired environment after either four or eight pairings and this avoidance persisted for at least 16 days following the final D 9 -THC injection. In contrast, adolescent rats showed no significant place aversion. Adult D 9 -THC-treated rats produced more vocalizations than adolescent rats when handled during the intoxicated state, also suggesting greater drug-induced aversion. After a 10-15 day washout, both adult and adolescent D 9 -THC pretreated rats showed decreased social interaction, while only D 9 -THC pretreated adolescent rats showed significantly impaired object recognition memory. Seventeen days following their last D 9 -THC injection, rats were euthanased and hippocampal tissue processed using two-dimensional gel electrophoresis proteomics. There was no evidence of residual D 9 -THC being present in blood at this time. Proteomic analysis uncovered 27 proteins, many involved in regulating oxidative stress/mitochondrial functioning and cytoarchitecture, which were differentially expressed in adolescent D 9 -THC pretreated rats relative to adolescent controls. In adults, only 10 hippocampal proteins were differentially expressed in D 9 -THC compared to vehicle-pretreated controls. Overall these findings suggest that adolescent rats find repeated D 9 -THC exposure less aversive than adults, but that cannabinoid exposure causes greater lasting memory deficits and hippocampal alterations in adolescent than adult rats.

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BACKGROUND Visit-to-visit clinic blood pressure variability (BPV) and 24-hour BPV have both been identified as independent risk factors for cardiovascular (CV) morbidity and mortality; however the mechanisms contributing to the increased CV risk as yet are unclear. The purpose of this study was to assess the relationship between BPV and endothelial function in a cohort of putatively healthy African Americans. METHODS 36 African Americans who were sedentary, non-diabetic, non-smoking, free of cardiovascular and renal disease and not on antihypertensive medication followed an American Heart Association low fat, low salt diet for 6 weeks. Upon completion of the 6-week dietary stabilization period, participants underwent 24-hour ambulatory BP monitoring and had their office BP measured on three separate days. Right brachial artery diameter was assessed at rest, during reactive hyperemia (flow-mediated dilation: FMD), and after nitroglycerin administration (nitroglycerin-mediated dilation: NMD). RESULTS Participants classified as having decreased endothelial function according to either %FMD or the FMD/NMD ratio had significantly higher 24-hour BPV and a trend for higher visit-to-visit BPV when compared to participants with normal endothelial function. Continuous variable analyses revealed a significant positive association between NMD and 24-hour diastolic BPV (DBPV). Visit-to-visit systolic BPV (SBPV), 24-hour SBPV, and 24-hour DBPV were all negatively associated with the FMD/NMD ratio. All relationships remained significant after adjustment for age, BMI, and mean BP levels. CONCLUSIONS These results may suggest that BPV is in increased in African Americans with decreased endothelial function and is associated with the vascular smooth muscle response to nitric oxide.

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Numerous assay methods have been developed to identify small-molecule effectors of protein kinases, but no single method can be applied to all isolated kinases. The authors developed a set of 3 high-throughput screening (HTS)-compatible biochemical assays that can measure 3 mechanistically distinct properties of a kinase active site, with the goal that at least 1 of the 3 would be applicable to any kinase selected as a target for drug discovery efforts. Two assays measure catalytically active enzyme: A dissociation-enhanced lanthanide fluoroimmuno assay (DELFIA) uses an antibody to quantitate the generation of phosphorylated substrate; a second assay uses luciferase to measure the consumption of adenosine triphosphate (ATP) during either phosphoryl-transfer to a peptide substrate or to water (intrinsic ATPase activity). A third assay, which is not dependent on a catalytically active enzyme, measures the competition for binding to kinase between an inhibitor and a fluorescent ATP binding site probe. To evaluate the suitability of these assays for drug discovery, the authors compared their ability to identify inhibitors of a nonreceptor protein tyrosine kinase from the Tec family, interleukin-2-inducible T cell kinase (ITK). The 3 assays agreed on 57% of the combined confirmed hit set identified from screening a 10,208-compound library enriched with known kinase inhibitors and molecules that were structurally similar. Among the 3 assays, the one measuring intrinsic ATPase activity produced the largest number of unique hits, the fewest unique misses, and the most comprehensive hit set, missing only 2.7% of the confirmed inhibitors identified by the other 2 assays combined. Based on these data, all 3 assay formats are viable for screening and together provide greater options for assay design depending on the targeted kinase. (Journal of Biomolecular

The purpose of this study was to investigate the association of visit-to-visit and 24-h BP variability with markers of endothelial injury and vascular function. We recruited 72 African Americans who were non-diabetic, non-smoking, and free of cardiovascular and renal disease. Office BP was measured at three visits and 24-h ambulatory BP monitoring was conducted to measure visit-to-visit and 24-h BP variability, respectively. The 5-min time-course of brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were assessed as measures of endothelial and smooth muscle function. Fasted blood samples were analyzed for circulating endothelial microparticles. Significantly lower CD31+CD42− endothelial microparticles were found in participants with high visit-to-visit SBP variability or high 24-h DBP variability. Participants with high visit-to-visit DBP variability had significantly lower flow-mediated dilation and higher nitroglycerin-mediated dilation at multiple time-points. When analyzed as continuous variables, 24-h mean arterial pressure variability was inversely associated with CD62+ endothelial microparticles; visit-to-visit DBP variability was inversely associated with flow-mediated dilation normalized by smooth muscle function and was positively associated with nitroglycerin-mediated dilation; and 24-h DBP variability was positively associated with nitroglycerin-mediated dilation. All associations were independent of age, gender, BMI, and mean BP. In conclusion, in this cohort of African Americans visit-to-visit and 24-h BP variability were associated with measures of endothelial injury, endothelial function, and smooth muscle function. These results suggest that BP variability may influence the pathogenesis of cardiovascular disease, in part, through influences on vascular health.

Acetate is a two carbon intermediate in metabolism. It is an accepted marker of astrocytic metabolism, and a substrate for production of metabolites such as glutamine, glutamate and GABA. However, anomalies exist in the current explanations of compartmentation and metabolism of acetate. Here, we investigated these anomalies by examining transport, production and metabolism of acetate. Acetate is a good substrate for the neuronal monocarboxylate transporter MCT2 (K(M) = 2.58 ± 0.8) and the glial MCT1 but a poor substrate for the glial MCT4. Acetate is accumulated by brain cortical tissue slices to concentrations in excess of those in the media, suggesting active transport, possibly via the sodium dependent SMCT. [2-(13)C]Acetate is produced from [3-(13)C]pyruvate, [3-(13)C]lactate and [1-(13)C]glucose with the rate of production related to acetyl-CoA levels, which is likely generated in a ubiquitous cytosolic compartment via acetyl-CoA hydrolase. Citrate breakdown occurs in response to demand for acetyl-CoA units; this citrate is not derived from acetate carbon but its fate is influenced by acetate levels. Finally, use of acetate is altered by levels of nicotinamide or NAD(+). This suggests that metabolism of acetate is controlled rigorously at the enzyme level, via changes in the acetylation status of acetyl-CoA synthetase and is not regulated by restriction of uptake.

Protease inhibition by secretory leukocyte protease inhibitor (SLPI) is accelerated by the sulfated polysaccharides. The nature of the SLPI-polysaccharide interaction, explored with affinity chromatography, indicated that this interaction was sensitive to the charge and type of polysaccharide. Dextran and chondroitin had the lowest affinity for SLPI, followed by dermatan, heparan, and dextran sulfates. While heparin bound SLPI tightly, the highest affinity heparin chains unexpectedly contained a lower level of sulfation than more weakly interacting chains. Heparin oligosaccharides, prepared using heparin lyase I were SLPI-affinity fractionated. Surprisingly, undersulfated heparin oligosaccharides bound SLPI with the highest affinity, suggesting the importance of free hydroxyl groups for high affinity interaction. Isothermal titration calorimetry was used to determine the thermodynamics of SLPI interaction with a low molecular weight heparin, an undersulfated decasaccharide and a tetrasaccharide. The studies showed 12-14 saccharide units, corresponding to molecular weight of ϳ4,800, were required for a 1:1 (SLPI:heparin) binding stoichiometry. Furthermore, an undersulfated decasaccharide was able to bind SLPI tightly (K d ϳ13 nM), resulting in its activation and the inhibition of neutrophil elastase and pancreatic chymotrypsin. The in vitro assessment of heparin and the decasaccharide and tetrasaccharide using stopped-flow kinetics suggested that heparin was the optimal choice to study SLPI-based in vivo protease inhibition. SLPI and heparin were co-administered by inhalation in therapy against antigen-induced airway hyperresponsiveness in a sheep bronchoprovocation model. Heparin, in combination with SLPI demonstrated in vivo efficacy reducing early and late phase bronchoconstriction. Heparin also increased the therapeutic activity of SLPI against antigen-induced airway hyperresponsiveness. Secretory leukocyte protease inhibitor (SLPI)1 is a nonglycosylated serine antiprotease with a molecular weight of 11,700 (29). It has been isolated from human bronchial secretions, seminal fluid, cervix uteri secretions, parotid saliva, articular cartilage chondrocytes, and intervertebral disc fibrochondrocyte (2, 3). The biological function of SLPI is believed to be the inhibition of elastase, cathepsin G, and other proteases, thereby protecting tissue from self-degradation by these enzymes (2, 4). SLPI is composed of two homologous domains and contains many positively charged amino acid residues (15 lysine and 5 arginine residues) (2). It is within clusters of these positively charged amino acid residues that the heparin polyanion probably interacts (5,14).Heparin is biosynthesized in mast cells as a proteoglycan consisting of a central core protein from which multiple glycosaminoglycan (GAG) chains extend (6 -8). On isolation and purification from tissue, such as lung, heparin is released from its protein core and isolated as a GAG. GAG heparin is a polydisperse, highly sulfated, linear polysaccharide comprised of repeati...