Vasodilation activity of dipfluzine metabolites in isolated rat basilar arteries and their underlying mechanisms

2020 ◽  
Vol 79 ◽  
pp. 103430
Author(s):  
Huan Wang ◽  
Shiji Li ◽  
Xiaohui Wang ◽  
Chaoxing He ◽  
Tianshi Wang ◽  
...  
Keyword(s):  
Basilar Arteries ◽  
Underlying Mechanisms ◽  
Isolated Rat

Three different vasoactive responses of rat tail artery to nicotine

1999 ◽  
Vol 78 (1) ◽  
pp. 20-28
Author(s):  
Rui Wang ◽  
Zunzhe Wang
Keyword(s):  
Smooth Muscles ◽  
Rat Tail Artery ◽  
Vascular Smooth Muscles ◽  
Vascular Effects ◽  
Tail Artery ◽  
Complete Relaxation ◽  
Underlying Mechanisms ◽  
Channel Currents ◽  
Rat Tail ◽  
Isolated Rat

The vasoactive effects of nicotine on isolated rat tail artery tissues were studied. Nicotine transiently contracted rat tail artery tissues (EC50, 55.6 ± 2 µM) in an extracellular Ca2+ dependent and endothelium-independent fashion. The blockade of alpha1-adrenoceptors, but not alpha2-adrenoceptors or P2X purinoceptors, inhibited the nicotine-induced contraction by 38 ± 7% (p < 0.05). Nicotine (1 mM) depolarized membrane by 13 ± 3 mV, but did not affect L-type Ca2+ channel currents, of the isolated rat tail artery smooth muscle cells. The phenylephrine-precontracted tail artery tissues were relaxed by nicotine (EC50, 0.90 ± 0.31 mM), which was significantly inhibited after the blockade of nicotinic receptors. Simultaneous removal of phenylephrine and nicotine, after a complete relaxation of the phenylephrine-precontracted tail artery strips was achieved by nicotine at accumulated concentrations (>=10 mM), triggered a Ca2+-dependent rebound long-lasting vasoconstriction (n = 20). This rebound contraction was abolished in the absence of calcium or in the presence of tetracaine in the bath solution. Pretreatment of vascular tissues with a nicotinic receptor antagonist did not affect the nicotine-induced vasoconstriction or nicotine withdrawal induced rebound contraction. The elucidation of the triphasic vascular effects of nicotine and the underlying mechanisms is important for a better understanding of the complex vascular actions of nicotine.Key words: nicotine, smokeless tobacco, vascular smooth muscles, contraction, relaxation.

scholarly journals Nebivolol reduces intracellular Ca 2+ and elicits dilations in isolated rat basilar arteries (1070.7)

2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Peter Cseplo ◽  
Zoltan Vamos ◽  
Istvan Batai ◽  
Orsolya Torok ◽  
Zsolt Springo ◽  
...  
Keyword(s):  
Intracellular Ca ◽  
Basilar Arteries ◽  
Isolated Rat

Ultrastructural changes in isolated rat liver perfused with cyclic heptapeptide toxins from norwegian freshwater cyanobacteria (blue-green algae)

1987 ◽  
Vol 45 ◽  
pp. 858-859
Author(s):  
A.S. Dabholkar ◽  
W.W. Carmichael ◽  
K. Berg ◽  
J. Wyman
Keyword(s):  
Ultrastructural Changes ◽  
Sprague Dawley ◽  
Isolated Rat Liver ◽  
Blue Green Algae ◽  
Sprague Dawley Rats ◽  
Cyclic Heptapeptide ◽  
Intracellular Changes ◽  
Oscillatoria Agardhii ◽  
Rat Livers ◽  
Isolated Rat

Intracellular changes in the hepatocytes of isolated rat livers perfused with cyclic heptapeptide toxins are described. The toxins used are 1) -Ala-Leu- β-methyl isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 944) from Microcystis aeruginosa- Lake Akersvatn, Norway; 2) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 1023) from Oscillatoria agardhii var. - Lake Kolbatnvatn, Norway; 3) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-dha (M.W. 1009) from Oscillatoria agardhii var. isothrix - Lake Froylandsvatn, Norway. Approximate LD intraperitoneal mouse for the toxins is 50, 500 and 1000 μg/kg respectively.Livers were removed from male Sprague Dawley rats and perfused for 15 min with a blood-free perfusate (50 ml) followed by 60 min with perfusate containing i) 25, 50, or 200 μg of M. aeruginosa toxin ii) 50, 250, 500 or 1000 μg of O. agardhii var. toxin and iii) 1000, 2000, 2500 or 5000 μg of O. agardhii var. isothrix toxin. Control livers were perfused for 75 min with the blood-free perfusate.

The limits of human performance

2008 ◽  
Vol 44 ◽  
pp. 11-26 ◽  
Author(s):  
Ralph Beneke ◽  
Dieter Böning
Keyword(s):  
Human Performance ◽  
Safety Margin ◽  
Afferent Input ◽  
Metabolic Energy ◽  
Human Organism ◽  
Mechanical Resistance ◽  
As Doping ◽  
Gene And Protein Expression ◽  
Underlying Mechanisms ◽  
Biochemical Research

Human performance, defined by mechanical resistance and distance per time, includes human, task and environmental factors, all interrelated. It requires metabolic energy provided by anaerobic and aerobic metabolic energy sources. These sources have specific limitations in the capacity and rate to provide re-phosphorylation energy, which determines individual ratios of aerobic and anaerobic metabolic power and their sustainability. In healthy athletes, limits to provide and utilize metabolic energy are multifactorial, carefully matched and include a safety margin imposed in order to protect the integrity of the human organism under maximal effort. Perception of afferent input associated with effort leads to conscious or unconscious decisions to modulate or terminate performance; however, the underlying mechanisms of cerebral control are not fully understood. The idea to move borders of performance with the help of biochemicals is two millennia old. Biochemical findings resulted in highly effective substances widely used to increase performance in daily life, during preparation for sport events and during competition, but many of them must be considered as doping and therefore illegal. Supplements and food have ergogenic potential; however, numerous concepts are controversially discussed with respect to legality and particularly evidence in terms of usefulness and risks. The effect of evidence-based nutritional strategies on adaptations in terms of gene and protein expression that occur in skeletal muscle during and after exercise training sessions is widely unknown. Biochemical research is essential for better understanding of the basic mechanisms causing fatigue and the regulation of the dynamic adaptation to physical and mental training.

Effect of Interleukin-8 on histamine release from isolated rat stomach

2001 ◽  
Vol 120 (5) ◽  
pp. A159-A159
Author(s):  
S RO ◽  
K YAKABI ◽  
T NAKAMURA
Keyword(s):  
Histamine Release ◽  
Interleukin 8 ◽  
Rat Stomach ◽  
Isolated Rat

Orienting and Focusing in Voluntary and Involuntary Visuospatial Attention Conditions

2010 ◽  
Vol 24 (3) ◽  
pp. 198-209 ◽  
Author(s):  
Yan Wang ◽  
Jianhui Wu ◽  
Shimin Fu ◽  
Yuejia Luo
Keyword(s):  
Gain Control ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Orientation Discrimination ◽  
Involuntary Attention ◽  
Attention Condition ◽  
Voluntary Attention ◽  
Visual Spatial ◽  
Related Potentials ◽  
Underlying Mechanisms

In the present study, we used event-related potentials (ERPs) and behavioral measurements in a peripherally cued line-orientation discrimination task to investigate the underlying mechanisms of orienting and focusing in voluntary and involuntary attention conditions. Informative peripheral cue (75% valid) with long stimulus onset asynchrony (SOA) was used in the voluntary attention condition; uninformative peripheral cue (50% valid) with short SOA was used in the involuntary attention condition. Both orienting and focusing were affected by attention type. Results for attention orienting in the voluntary attention condition confirmed the “sensory gain control theory,” as attention enhanced the amplitude of the early ERP components, P1 and N1, without latency changes. In the involuntary attention condition, compared with invalid trials, targets in the valid trials elicited larger and later contralateral P1 components, and smaller and later contralateral N1 components. Furthermore, but only in the voluntary attention condition, targets in the valid trials elicited larger N2 and P3 components than in the invalid trials. Attention focusing in the involuntary attention condition resulted in larger P1 components elicited by targets in small-cue trials compared to large-cue trials, whereas in the voluntary attention condition, larger P1 components were elicited by targets in large-cue trials than in small-cue trials. There was no interaction between orienting and focusing. These results suggest that orienting and focusing of visual-spatial attention are deployed independently regardless of attention type. In addition, the present results provide evidence of dissociation between voluntary and involuntary attention during the same task.

Response Interference as a Mechanism Underlying Implicit Measures

2008 ◽  
Vol 24 (4) ◽  
pp. 218-225 ◽  
Author(s):  
Bertram Gawronski ◽  
Roland Deutsch ◽  
Etienne P. LeBel ◽  
Kurt R. Peters
Keyword(s):  
Task Performance ◽  
Psychological Research ◽  
Implicit Measures ◽  
Mediation Model ◽  
Response Interference ◽  
Relevant Evidence ◽  
Moderated Mediation Model ◽  
Stimulus Features ◽  
Underlying Mechanisms

Over the last decade, implicit measures of mental associations (e.g., Implicit Association Test, sequential priming) have become increasingly popular in many areas of psychological research. Even though successful applications provide preliminary support for the validity of these measures, their underlying mechanisms are still controversial. The present article addresses the role of a particular mechanism that is hypothesized to mediate the influence of activated associations on task performance in many implicit measures: response interference (RI). Based on a review of relevant evidence, we argue that RI effects in implicit measures depend on participants’ attention to association-relevant stimulus features, which in turn can influence the reliability and the construct validity of these measures. Drawing on a moderated-mediation model (MMM) of task performance in RI paradigms, we provide several suggestions on how to address these problems in research using implicit measures.

The More You Say, the Less They Hear

2015 ◽  
Vol 27 (4) ◽  
pp. 159-169 ◽  
Author(s):  
Elsbeth D. Asbeek Brusse ◽  
Marieke L. Fransen ◽  
Edith G. Smit
Keyword(s):  
Hearing Protection ◽  
Entertainment Education ◽  
Mediating Role ◽  
Attitude Measures ◽  
Underlying Mechanisms

Abstract. This study examined the effects of disclosure messages in entertainment-education (E-E) on attitudes toward hearing protection and attitude toward the source. In addition, the (mediating) role of the underlying mechanisms (i.e., transportation, identification, and counterarguing) was studied. In an experiment (N = 336), three different disclosure messages were compared with a no-disclosure condition. The results show that more explicit disclosure messages negatively affect transportation and identification and stimulate the generation of counterarguments. In addition, the more explicit disclosure messages affect both attitude measures via two of these processes (i.e., transportation and counterarguing). Less explicit disclosure messages do not have this effect. Implications of the findings are discussed.

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