Samad Tadjkarimi

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STUDY OBJECTIVE The aim of the study was to investigate the receptor events that mediate the vascular effects of 5-hydroxytryptamine (5-HT) on human coronary arteries, since 5-HT has long been thought to play a role in coronary artery vasospasm. DESIGN Recently available selective receptor agonists and antagonists were used to examine the 5-HT receptor(More)
8-Epi-prostaglandin F2 alpha (8-epi-PGF2 alpha) is an F2-isoprostane formed via a noncyclooxygenase pathway. We investigated whether 8-epi-PGF2 alpha has any effects on isolated guinea-pig and human airway smooth-muscle tone, and characterized the receptor involved in these effects. Cumulative concentration responses to 8-epi-PGF2 alpha in the absence or(More)
BACKGROUND Platelet aggregation with the release of their vasoactive mediators is an important factor contributing to the patency of coronary bypass grafts. However, the role of leukocyte-derived mediators on graft performance is unclear. Leukotrienes (LTs) are proinflammatory mediators released from a variety of leukocytes that possess both vasoactive and(More)
Double-lung transplantation with tracheal anastomosis has previously resulted in unacceptable ischemic complications of airway healing. Three patients underwent double-lung transplantation at our institution in 1986 and 1987, and 2 of these required later retransplantation because of airway complications. Recently, we began to perform direct(More)
We investigated the effect of Ba 679 BR, a novel long-acting antimuscarinic agent, on cholinergic neural responses in guinea pig and human airways. Ba 679 BR, atropine, and ipratropium bromide inhibited electrical field stimulation (EFS)-induced contraction with IC50 values of 0.17, 0.74, and 0.58 nM, respectively, in guinea pig trachea. Ba 679 BR had a(More)
BACKGROUND Platelets release two powerful vasoconstrictors--thromboxane A2 (TXA2) and 5-hydroxytryptamine (5-HT). Animal studies have suggested that these two substances may act in a synergistic fashion to stimulate platelet activity and smooth muscle vasoconstriction. METHODS AND RESULTS To assess the interaction between TXA2 and 5-HT at the individual(More)
The aim of this study was to investigate the roles of heat shock proteins and catalase after heat shock stress in the recovery of cardiac mechanical and endothelial function following a prolonged ischemic, cardioplegic arrest. Isolated working rat hearts were subjected to an ischemic cardioplegic arrest for 4 hours at 4 degrees C. Six groups, each of 6(More)
Leukotrienes, lipid mediators derived from arachidonic acid by the 5-lipoxygenase pathway, have been implicated in a variety of myocardial ischemic events including myocardial infarction and coronary spasm. We have examined the comparative effects of leukotriene C4 in isolated human non-atherosclerotic and atherosclerotic coronary arteries to gain an(More)
Human airway smooth muscle possesses an inhibitory nonadrenergic noncholinergic neural bronchodilator response mediated by nitric oxide (NO). In guinea pig trachea both endogenous NO and vasoactive intestinal peptide (VIP) modulate cholinergic neural contractile responses. To identify whether endogenous NO or VIP can modulate cholinergic contractile(More)
Patency rates of bypass graft conduits are thought to be influenced by the determinants of vascular tone. This study has comparatively examined the response of the human internal mammary and gastroepiploic arteries to potassium, noradrenaline, dopamine, 5-hydroxytryptamine, thromboxane, and histamine. The response to potassium was significantly greater in(More)