Tissue bioavailability of anthocyanins from whole tart cherry in healthy rats.

Our aim was to confirm and identify the presence of tart cherry anthocyanins in several target tissues of healthy rats. Liquid chromatography-mass spectrometry analysis was employed for detection and characterisation of anthocyanin metabolites. It was shown that four native anthocyanins, namely cyanidin 3-glucosylrutinoside, cyanidin 3-rutinoside, cyanidin 3-rutinoside 5-β-D-glucoside, and peonidin 3-rutinoside were differentially distributed among targeted tissues of rats.

Differential effects of opioid peptides on myocardial ischemic tolerance.

Background: Opioid peptides, which can induce mammalian hibernation, may provide protection against subcellular and molecular changes during hypothermic myocardial ischemia. This study examined the differential effects of the three known myocyte opioid receptors, Mu (micro), Delta (delta), and Kappa (kappa), in augmenting myocardial ischemic tolerance.

Methods: Control hearts (CH) were compared to hearts pretreated with either the micro-agonist, fentanyl, the delta-agonist, DADLE, or delta-antagonist, NTB, or the kappa-agonist, U50488H (U50), or kappa-antagonist, nor-BNI.

Relative contribution of endogenous opioids to myocardial ischemic tolerance.

Background: Opioid preconditioning by exogenous opioids experimentally protects the myocardium against ischemia/reflow injury. Additionally, endogenous opioid peptides released during ischemia also enhance ischemic tolerance. Promiscuous opioid receptor agonists conceal the differential contribution of the mu, delta, and kappa opioid subtypes.

Prolonged lipopolysaccharide inhibits leukotriene synthesis in peritoneal macrophages: mediation by nitric oxide and prostaglandins.

Resident rat peritoneal macrophages synthesize a variety of prostanoids and leukotrienes from arachidonic acid. Overnight treatment with lipopolysaccharide (LPS) induces the synthesis of cyclooxygenase-2 (COX-2) and an altered prostanoid profile that emphasizes the preferential conversion of arachidonic acid to prostacyclin and prostaglandin E2. In these studies, we report that exposure to LPS also caused a strong suppression of 5-lipoxygenase but not 12-lipoxygenase activity, indicated by the inhibition of synthesis of both leukotriene B4 and 5-hydroxyeicosatetraenoic acid (5-HETE), but not of 12-HETE.