1 The effect of tetraethylammonium (TEA) and 4-aminopyridine (4-AP) on the inhibitory effect of guanethidine on noradrenaline (NA) release was investigated in the perfused spleen of the cat. 2 Guanethidine blocked the release of NA evoked by nerve stimulation. TEA and 4-AP readily reversed this inhibitory effect, and the NA output was nearly doubled after repeated stimulation of the nerves. On subsequent perfusion with Krebs solution without TEA or 4-AP, the inhibitory effect of guanethidine reappeared. 3 The reversal of guanethidine blockade of sympathetic nerves by TEA and 4-AP is discussed.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1667782PMC
http://dx.doi.org/10.1111/j.1476-5381.1978.tb07008.xDOI Listing

Publication Analysis

Top Keywords

tea 4-ap
12
reversal guanethidine
8
guanethidine blockade
8
blockade sympathetic
8
4-ap inhibitory
8
inhibitory guanethidine
8
sympathetic nerve
4
nerve terminals
4
terminals tetraethylammonium
4
tetraethylammonium 4-aminopyridine
4

Similar Publications

Potassium channels mediate nitric oxide-induced vasorelaxation in arteries supplying colon cancer.

Prostaglandins Other Lipid Mediat

December 2024

Department of Biology, College of Science, University of Zakho, Duhok, Kurdistan Region, Iraq; Department of Biology, College of Science, University of Nawroz, Duhok, Kurdistan Region, Iraq.

Introduction: Aberrant vascular function and cancer growth are closely related, with nitric oxide (NO) being a key factor in vascular tone regulation. This study provides Novel insights into the distinctive mechanisms underlying cancer-associated vascular dysfunction by investigating the involvement of potassium (K) channels in NO-mediated vasorelaxation within arteries supplying colon cancer.

Methods: Arterial segments from colon cancer patients were isolated and sectioned into rings, these rings were mounted in an organ bath filled with Krebs' solution and maintained at 37°C.

View Article and Find Full Text PDF

Carob leaves: Phytochemistry, antioxidant properties, vasorelaxant effect and mechanism of action.

J Ethnopharmacol

December 2024

Laboratory of Bioresources, Biotechnologies, Ethnopharmacology and Health, Department of Biology, Faculty of Sciences, University Mohammed First, Oujda, 60000, Morocco. Electronic address:

Ethnopharmacological Relevance: Ceratonia siliqua L., is a species of significant nutritional and industrial interest with extensive traditional uses. This fabaceae is renowned for its medicinal properties, including the treatment of high blood pressure.

View Article and Find Full Text PDF

Effect of Hydrogen Sulfide on Sympathoinhibition in Obese Pithed Rats and Participation of K Channel.

Int J Hypertens

November 2024

Departamento de Farmacobiología, Cinvestav-Coapa, Czda. de Los Tenorios 235, Col. Granjas-Coapa, Alc. Tlalpan, C.P. 14330, Ciudad de México, Mexico.

Elevated blood pressure is the leading metabolic risk factor in attributable deaths, and hydrogen sulfide (HS) regulates vascular tone and blood pressure. Thus, this study aims to evaluate the mechanism by which NaHS (HS donor) produces inhibition of the vasopressor sympathetic outflow in obese rats. For that purpose, animals were fed a high-fat diet (HFD) (60% calories from fat) for 12 weeks.

View Article and Find Full Text PDF

The gram-negative toxin lipopolysaccharides (LPS) are known to trigger inflammatory cytokines in mammals, which can result in pathological responses. Upon treatment of bacterial sepsis with antibiotics, the lysing bacteria can present a surge in LPS, inducing a cytokine storm. However, LPS can also have direct cellular effects, including transient rapid hyperpolarizing of the membrane potential, blocking glutamate receptors and even promoting release of glutamate.

View Article and Find Full Text PDF

Vasorelaxant effect of phenylpropanoids: Methyl eugenol and eugenol in human umbilical cord vein.

Biomed Pharmacother

September 2024

Postgraduate Program in Physiological Sciences of the Universidade Estadual do Ceará - PPGCF/UECE, Fortaleza, Ceará, Brazil; Postgraduate Program in Biological Chemistry of the Universidade Regional do Cariri - PPQB/URCA, Crato, Ceará, Brazil.

Methyl-eugenol (ME) and eugenol (EUG) are phenylpropanoids with vasodilatory effects. While EUG's vasorelaxant effect in human umbilical artery (HUA) is known, their action in veins is unclear. This study aimed to evaluate ME and EUG in human umbilical vein (HUV).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!