BACKGROUND Sclerocarya birrea (Anacardiaceae) is traditionally used for treating hypertension. The pharmacological effects of S birrea leaf aqueous extract (SBE) on rabbit and rat vascular smooth muscles were investigated in this study. METHODS Fresh S birrea leaves (1 kg) were air dried at 26 ± 1°C, milled, macerated in 2.5 l of distilled water for 48 hours, filtered, and the filtrate was co...

Clinical evidence suggests that early endothelial cell (EC) dysfunction may predict the development of graft vascular disease. We wished to assess the early functional and morphological changes in the graft endothelium in a commonly used animal model of graft vascular disease, the rat aortic interposition allograft model. To assess graft EC function, regulation of vascular tone by ECs was monit...

Endothelium-derived relaxing factors contribute to smooth muscle relaxation. The aim of the present study was to investigate the contribution of nitric oxide (NO) produced in the endothelial cells to the vasodilatation stimulated with forskolin in rat aorta. Forskolin that directly activates adenylyl-cyclase, induced complete relaxation in phenylephrine-contracted aortas. Endothelium removal re...

Derivatives of salicylic acid (SA) and benzoic acid prevent endothelin-1 (ET-1) binding to ETA receptors. This study analyzed actions of 30 derivatives of benzoic acid and salicylic acid on (125)I-ET-1 binding to recombinant rat ETA receptors. The most active compounds were 3,5-dibromosalicylic acid (Br2SA, K(i) = 0.5 mM) and 3,5-diiodosalicylic acid (K(i) = 0.3 mM). They were about 50 times mo...

To determine if vascular smooth muscle from teleost and agnathan fishes expresses receptors for signaling agents that are important in vascular tension in other vertebrates, we exposed rings of aortic vascular smooth muscle from the eel (Anguilla rostrata), the hagfish (Myxine glutinosa), and the lamprey (Petromyzon marinus) to a suite of putative agonists, including: acetylcholine, endothelin,...

The aim of this study was to ascertain the effects of α-lipoic acid (ALA) treatment on relaxant responses of acetylcholine (ACh) and isoprenaline (ISO) in aortic rings precontracted with serotonin (5-HT, 10(-6) M) obtained from streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in the rats by 50 mg/kg streptozotocin (STZ) via an intraperitoneal injection. Rat body and aorta weight...

OBJECTIVE We investigated endothelial dysfunction and the role of angiotensin (Ang)-II type I (AT1-R) and type II (AT2-R) receptor in the changes in the Ang-II sensitivity in experimental preeclampsia in the rat. METHODS Aortic rings were isolated from low dose lipopolysaccharide (LPS) infused pregnant rats (experimental preeclampsia; n=9), saline-infused pregnant rats (n=8), and saline (n=8)...

This study was designed to examine whether NO regulates protein glutathiolation. Exposure to NO donors increased protein glutathiolation in COS-7 or rat aortic smooth muscle cells as detected by anti-protein glutathione (GSH) antibodies. This process was reversible and saturable. Stimulation with acetylcholine (ACh) increased protein glutathiolation in isolated rat aortic rings. This was preven...

To test the hypothesis that prostanoids contribute to angiotensin II-induced vascular contraction, we compared the effect of angiotensin II on isometric tension development by rings of descending thoracic aorta bathed in Krebs' bicarbonate buffer with and without indomethacin (10 microM) to inhibit cyclooxygenase, CGS13080 (10 microM) to inhibit thromboxane A2 synthesis, or SQ29548 (1 microM) t...