P1530Vasorelaxation as a mechanism of procyanidin B2 cardioprotective effect

Introduction

Findings from epidemiological studies indicate that polyphenols, widespread in human diet and with numerous biological activities, act cardioprotectively. Procyanidins are subclass of polyphenols with high content in commonly consumed foods and beverages, such as grapes, tea, chocolate, nuts and apples. Cardioprotective abilities of procyanidins, might, at least in part, attribute to their vasodilator properties.

Purpose

Because the exact mechanisms by which procyanidin B2 causes vasorelaxation are unclear, we aimed to investigate relaxant effect of procyanidin B2 on the isolated human internal mammary artery (HIMA) and its underlying mechanisms.

Methods

The HIMA segments were collected from patients suffering from coronary artery disease who were undergoing coronary artery bypass surgery and studied in organ bath.

Results

Procyanidin B2 induced strong concentration-dependent relaxation of HIMA rings pre-contracted by phenylephrine. Pretreatment with L-NAME, a NO synthase inhibitor, hydroxocobalamin, a NO scavenger, and ODQ, an inhibitor of soluble guanylate cyclase, significantly inhibited procyanidin B2-induced relaxation of HIMA, while indomethacin, a cyclooxygenase inhibitor, considerably reduced effects of low concentrations. Among K+ channel blockers, iberiotoxin, a selective blocker of large conductance Ca2+-activated K+ channels (BKCa), abolished procyanidin B2-induced relaxation, glibenclamide, a selective ATP-sensitive K+ (KATP) channel blocker, induced partial inhibition, while 4-aminopyridine, a blocker of voltage-gated K+ (KV) channels, and TRAM-34, an inhibitor of intermediate-conductance Ca2+-activated K+ (IKCa) channels, slightly reduced maximal relaxation of HIMA.

Conclusion

Our results demonstrate that, in HIMA, procyanidin B2 produces strong endothelium-dependent vasorelaxant effect. It seems that this relaxation is primarily the result of an increased NO synthesis and secretion by endothelial cells and partially of prostacyclin, although it involves activation of BKCa and KATP, as well as KV and IKCa channels in high concentrations of procyanidin B2.

Acknowledgement/Funding

The study was supported by a Scientific Research Grant (P175088) from Ministry of Science and Technology Serbia.

The radial artery for coronary artery bypass grafting

Coronary artery bypass grafting (CABG) is the standard surgical procedure for the treatment of advanced coronary artery disease. CABG surgery has been demonstrated to improve symptoms and, in specific subgroups of patients, to prolong life. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. Previous long-term studies have shown unsatisfactory patency of saphenous vein grafts used for myocardial revascularisation, compared with internal mammary artery grafts. Recently, the use of radial artery for CABG has enjoyed a revival, on the basis of the belief that it will help improving long-term results of coronary operations. The recent reports of encouraging mid-term and long-term patency rates of the radial artery, supports its continued use as a bypass conduit. In this paper, we review the current knowledge about the radial artery as a bypass graft, with special emphasis on the clinical results.

Cloning and characterization of an ionotropic glutamate receptor subunit expressed in the squid nervous system

In this paper we describe the cloning of a putative ionotropic glutamate receptor subunit, SqGluR, and its distribution in the nervous system of the squid. A full-length cDNA was assembled from a cDNA library of the stellate ganglion/giant fibre lobe complex of Loligo opalescens. The deduced amino acid sequence of the mature SqGluR displayed 44-46% amino acid identity with mammalian GluR1-GluR4 and 53% with Lym-eGluR1 from Lymnaea stagnalis. In situ hybridizations in adult squid confirmed that the SqGluR mRNA is abundant in giant fibre lobe neurons, in large, presumptive motor neurons of the stellate ganglion proper and in the supraoesophageal and optic lobes of the central nervous system. In newborn squid, SqGluR mRNA expression was detected throughout the nervous system but not elsewhere. A synthetic peptide corresponding to the last 15 amino acids of the SqGluR C-terminus was used to generate polyclonal antibodies, which were used for immunoblot analysis to demonstrate widespread expression in the squid central and peripheral nervous systems. Injection of the synthetic peptide into the postsynaptic side of the giant synapse inhibited synaptic transmission.

An exploration of the nature and causes of distress in women attending gynecology outpatient clinics

This study evaluates the distress experienced by women attending gynecology outpatient clinics (GOCs). We investigate causes of this distress and explore women's own experience of their distress. A questionnaire survey of 197 women attending GOCs was carried out, both quantitative and qualitative analyses were undertaken. Thirty-five percent of women showed clinical levels of anxiety, 13% had clinically significant depression and half reported feeling distressed. A range of feelings was reported, though commonly mixed emotions were expressed. Women had a low sense of personal control and uncertainty in relation to their gynecologic problem. Both coincidental stress, such as life changes, and the direct consequences of the gynecologic problem were predictive of anxiety. Qualitative analysis suggested four ways in which women experienced their distress and the gynecologic problem: (i) gynecologic symptoms were a direct cause of distress, (ii) gynecologic symptoms caused distress indirectly through reactions to diagnosis and treatment, (iii) gynecologic symptoms caused distress because of their impact on relationships, social life and self identity, and (iv) distress was unrelated to the gynecologic symptoms. Results highlight diversity and complexity in women's experiences and support the need for a fuller understanding of distress in this group in order to meet their needs adequately and appropriately.