Search results for "Calcium"
showing 10 items of 1740 documents
Essential oil of Sicilian Prangos ferulacea (L.) Lindl. and its major component, β−ocimen, affect contractility in rat small and large intestine
2023
Ethnopharmacological relevance: Prangos ferulacea (L.) Lindl is an Apiaceae plant, widely used in traditional medicine. Recently, chemical composition and biological activities of its essential oil (Prangroil) have been reported, but there are no studies on possible effects on intestinal contractility. Aims of the study: We investigated the effects of essential oil Sicilian Prangoil on the contractility of rat small (duodenum) and large (colon) intestine and the related action mechanism. Materials and methods: Responses to Prangoil and to its major component β-ocimen in intestinal segments were assessed in vitro as changes in isometric tension. Results: Prangoil, induced in duodenum, depend…
Die Noradrenalin-Abgabe aus dem isolierten Kaninchenherzen bei sympathischer Nervenreizung und ihre pharmakologische Beeinflussung
1962
Kinetics and state-dependent effects of verapamil on cardiac L-type calcium channels.
1996
The voltage dependence and the kinetics of block by verapamil of L-type calcium current (ICa) were investigated in ventricular myocytes from rat hearts using the whole-cell patch-clamp technique. ICa was elicited repetitively in response to depolarizing voltage pulses from -80 mV to 0 mV at different pulse intervals and durations. Verapamil reduced the magnitude of ICa in a frequency-dependent manner without tonic component. The time course of ICa remained unchanged suggesting that not open but inactivated channels were affected by the drug. The interaction of verapamil with inactivated channels was investigated by the application of twin pulses. In the presence of verapamil, the duration o…
Dinoflagellates from marine algal blooms produce neurotoxic compounds: effects on free calcium levels in neuronal cells and synaptosomes
2000
In this report, evidence is presented that the marine unicellular eukaryotic dinoflagellates can cause neurotoxicity very likely by an increase in intracellular free calcium ions ([Ca(2+)](i)). Determinations of the effects of culture supernatants from different clones of the dinoflagellate Alexandrium sp. isolated from algal blooms on the viability of rat primary neuronal cells revealed that all clones tested were toxic for these cells. In addition, all Alexandrium clones tested, except for A. ostenfeldii BAH ME-141, were found to be toxic for rat pheochromocytoma PC12 cells. No toxicity was observed for culture supernatants from Gonyaulax and Coolia monotis. Calcium ions are important in …
Mitochondrial basis of the anti-arrhythmic action of lidocaine and modulation by the n-6 to n-3 PUFA ratio of cardiac phospholipids
2012
The aim of this study was to evaluate the involvement of mitochondria in the mechanism of the anti-arrhythmic lidocaine. Rats were fed with a diet containing either n-6 polyunsaturated fatty acids (PUFAs, SSO group) or an equimolecular mixture of n-3 and n-6 PUFAs (FO group) for 8 weeks. The hearts were perfused according to the working mode using a medium with or without lidocaine 5 μM. They were then subjected to local ischemia (20 min) and reperfusion (30 min). Dietary n-3 PUFAs triggered the expected decrease in the n-6/n-3 PUFA ratio of cardiac phospholipids. Reperfusing the ischemic area favored the incidence of severe arrhythmias. Lidocaine treatment abolished almost completely reper…
Der Einfluss von Acetylcholin auf den Calciumumsatz ruhender und kontrahierender Vorhofmuskulaturin vitro
1964
Acetylcholine 5 × 10−8 g/ml reduces the Ca45 uptake of the beating left atria of guinea-pig; the tissue calcium is not altered. In resting atria, acetylcholine 5 × 10−7 g/ml has no influence upon the calcium content and Ca45 uptake. It is concluded that acetylcholine acts by shortening the action potential duration and thereby reduces the release of cellular calcium per excitation.
Effect of nimodipine on rheologic parameters in patients with chronic cerebrovascular disease
1992
Abstract Sixteen patients with chronic cerebrovascular disease were treated with a monotherapeutic regimen of nimodipine 30 mg orally three times a day. At baseline and after 45 and 90 days of therapy, the patients' whole blood filterability, erythrocyte membrane fluidity, red blood cell membrane protein lateral mobility, and red blood cell Ca 2+ content (total and cytosolic) were evaluated. After 45 days, an increase in whole blood filterability and a decrease in the cytosolic red cell Ca 2+ content was seen. At the end of treatment, whole blood filterability, erythrocyte membrane fluidity, and red cell membrane protein lateral mobility had increased, compared with baseline values, while t…
The cAMP Pathway Sensitizes VR1 Expressed in Oocytes from <i>Xenopus laevis</i> and in CHO Cells
2003
The vanilloid receptor 1 (VR1) is a heat-activated cation channel which also responds to capsaicin and other chemical stimuli. Protein kinase C has a stimulatory effect on VR1 activity, either alone or after activation with capsaicin. The influence of the cAMP-signaling pathway on the effects of capsaicin is controversial. To clarify this, the actions of capsaicin and the modulatory effects of forskolin, pCPT-cAMP, and isobutylmethylxanthine were studied in <i>Xenopus laevis</i> oocytes expressing rat VR1 and in CHO cells expressing human VR1. Capsaicin activated the VR1 channel and increased the intracellular calcium concentration. The effects of capsaicin were enhanced by fors…
pH-dependent hydrolysis of acetylcholine: Consequences for non-neuronal acetylcholine
2015
Acetylcholine is inactivated by acetylcholinesterase and butyrylcholinesterase and thereby its cellular signalling is stopped. One distinguishing difference between the neuronal and non-neuronal cholinergic system is the high expression level of the esterase activity within the former and a considerably lower level within the latter system. Thus, any situation which limits the activity of both esterases will affect the non-neuronal cholinergic system to a much greater extent than the neuronal one. Both esterases are pH-dependent with an optimum at pH above 7, whereas at pH values below 6 particularly the specific acetylcholinesterase is more or less inactive. Thus, acetylcholine is prevente…