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Vanilloid receptors on capsaicin-sensitive sensory nerves mediate relaxation to methanandamide in the rat isolated mesenteric arterial bed and small mesenteric arteries

1. In the present study, the vasodilator actions of methanandamide and capsaicin in the rat isolated mesenteric arterial bed and small mesenteric arterial segments were investigated. 2. Methanandamide elicited concentration-dependent relaxations of preconstricted mesenteric arterial beds (pEC 50 = 6.0 ± 0.1, E(max) = 87 ± 3%) and arterial segments (pEC 50 = 6.4 ± 0.1, E(max) = 93 ± 3%). 3. In art

Vanilloid receptors on sensory nerves mediate the vasodilator action of anandamide

The endogenous cannabinoid receptor agonist anandamide is a powerful vasodilator of isolated vascular preparations, but its mechanism of action is unclear. Here we show that the vasodilator response to anandamide in isolated arteries is capsaicin-sensitive and accompanied by release of calcitonin- gene-related peptide (CGRP). The selective CGRP-receptor antagonist 8-37 CGRP (ref. 5), but not the c

Interactions between endothelium-derived relaxing factors in the rat hepatic artery : Focus on regulation of EDHF

1. In rat isolated hepatic arteries contracted with phenylephrine, acetylcholine and the calcium ionophore A23187 each elicit endothelium-dependent relaxations, which involve both nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF). However, the contribution of prostanoids to these responses, and the potential interaction between EDHF and other endothelium-derived relaxing fact

Characterization of endothelium-dependent relaxation in guinea pig basilar artery - Effect of hypoxia and role of cytochrome P450 mono- oxygenase

In the guinea pig basilar artery, acetylcholine and the calcium ionophore A23187 induced endothelium-dependent relaxations, which were not significantly affected by the nitric oxide (NO) synthase inhibitor N(ω)- nitro-L-arginine (L-NOARG; 0.3 mM) or the guanylate cyclase inhibitor ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one; 1-10 μM), or by these inhibitors combined. However, acetylcholine (

Studies on the effects of anandamide in rat hepatic artery

1. The effects of anandamide on K+ currents and membrane potential have been examined in freshly-isolated smooth muscle cells from rat hepatic artery and the results compared with the effects of this arachidonic acid derivative on tension and membrane potential changes in segments of whole artery. 2. In the presence of 0.3 mM L-NOARG and 10 μM indomethacin, anandamide (0.1-100 μM) and endothelium-

Involvement of voltage-dependent potassium channels in the EDHF-mediated relaxation of rat hepatic artery

1. In the rat hepatic artery, the acetylcholine-induced relaxation mediated by endothelium-derived hyperpolarizing factor (EDHF) is abolished by a combination of apamin and charybdotoxin, inhibitors of small (SK(Ca)) and large (BK(Ca)) conductance calcium-sensitive potassium (K)-channels, respectively, but not by each toxin alone. The selective BK(Ca) inhibitor iberiotoxin cannot replace charybdot

Characterization of the potassium channels involved in EDHF-mediated relaxation in cerebral arteries

1. In the presence of N(G)-nitro-L-arginine (L-NOARG, 0.3 mM) and indomethacin (10 μM), the relaxations induced by acetylcholine and the calcium (Ca) ionophore A23187 are considered to be mediated by endothelium-derived hyperpolarizing factor (EDHF) in the guinea-pig basilar artery. 2. Inhibitors of adenosine 5'-triphosphate (ATP)-sensitive potassium (K)-channels (K(ATP); glibenclamide, 10 μM), vo

Effects of cytochrome P450 inhibitors on EDHF-mediated relaxation in the rat hepatic artery

1. The possibility that the endothelium-derived hyperpolarising factor (EDHF) in the rat hepatic artery is a cytochrome P450 mono-oxygenase metabolite of arachidonic acid was examined in the present study. In this preparation, acetylcholine elicits EDHF-mediated relaxations in the presence of the nitric oxide (NO) synthase and cyclo-oxygenase inhibitors N(ω)-nitro-L-arginine (L-NOARG) and indometh

Role of potassium channels in endothelium-dependent relaxation resistant to nitroarginine in the rat hepatic artery

1. In the presence of indomethacin (IM, 10 μM) and N(ω)-nitro-L-arginine (L-NOARG, 0.3 mM), acetylcholine (ACh) induces an endothelium-dependent smooth muscle hyperpolarization and relaxation in the rat isolated hepatic artery. The potassium (K) channel inhibitors, tetrabutylammonium (TBA, 1 mM) and to a lesser extent 4-aminopyridine (4-AP, 1 mM) inhibited the L-NOARG/IM-resistant relaxation induc

Effects of cytochrome P450 inhibitors on potassium currents and mechanical activity in rat portal vein

1. The effects of the cytochrome P450 inhibitors, proadifen, clotrimazole and 17-octadecynoic acid (17-ODYA) on K-currents in freshly-isolated single cells derived from rat portal vein and on mechanical activity in whole veins were studied. 2. When cells were stepped from -90 mV to a series of test potentials (from -80 to +50 mV), a delayed rectifier current (I(K(V))) and an A-type current ((IK(A)

NANC neurotransmission in lamina propria of the rabbit urethra : regulation by different subsets of calcium channels

Electrical field stimulation (EFS) of the rabbit urethral lamina propria elicited a frequency‐dependent non‐adrenergic, non‐cholinergic (NANC) relaxation, which was abolished by NΩ–nitro‐L‐arginine (l‐NOARG). Ω‐Conotoxin GVIA, a selective blocker of N‐type voltage‐operated calcium channels (VOCCs), and Ω‐conotoxin MVIIC (blocker of N‐ and Q‐type VOCCs) inhibited the NANC relaxation, and the inhibi

Regional differences in endothelium‐dependent relaxation in the rat : contribution of nitric oxide and nitric oxide‐independent mechanisms

Relaxant effects of acetylcholine (ACh), histamine, calcitonin gene‐related peptide (CGRP) and the calcium ionophore A23187 were examined in rat femoral (Ø ≅ 0.2 mm), mesenteric (0.2 mm), intrarenal (0.2 mm) and hepatic (0.3 mm) arteries, and aorta (2 mm). Acetylcholine elicited an endothelium‐dependent relaxation in all arteries. Histamine induced an endothelium‐dependent relaxation in aorta, and

Endothelium‐dependent relaxation resistant to N/ω‐nitro‐L‐arginine in the rat hepatic artery and aorta

Nitric oxide (NO)‐independent pathways contributing to acetylcholine (ACh)‐induced relaxation were examined in the rat isolated hepatic artery and aorta at low and high levels of precontraction induced by phenylephrine (PhE). In the hepatic artery, the ACh‐induced relaxation was unaffected by the NO synthase inhibitors Nw‐nitro‐L‐arginine (L‐NOARG, 0.3 mM) and Nω‐nitro‐L‐arginine methyl ester (0.1

Obesutten och osynliggjord : En betraktelse över historisk arkeologi på marginalen

In the 19th and early 20th centuries there were numerous non-proprietors paupers in the Swedish countryside such as crofters, boarders and inhabitants of rural slums. With a change in the heritage legislation, increased possibilities to archaeologically investigate the non-proprietors of the recent past have emerged, but the archaeological material is still both scarce and of a repetitive characteIn the 19th and early 20th centuries there were numerous non proprietor, poor and pauper people in the Swedish countryside such as crofters, boarders and inhabitants of rural slums. With a change in the heritage legislation, increased possibilities to archaeologically investigate the non proprietors of the recent past has emerged, however the archaeological material is still both scarce and of a r

Det gränslösa samhället : Om hur goda idéer kan leda till ojämlikhet/utestängning

En plattityd; samhället är delat. Lite mera nyanserat; det verkar finnas en tendens till att strukturera den mänskliga samvarons former. Individer, liksom aktiviteter, separeras i olika kategorier vilka rangordnas mer eller mindre relevant för samhällets fungerande. Dessa processer sker utan att någon av de inblandade har något intresse i en sådan strukturering. Det kan till och med vara s