Search results for "element"

Effect of the stable prostacyclin analogue iloprost on water and electrolyte transfer of the rat ileum and colon in vivo.

1988

The effect of iloprost on water and ion transfer was measured simultaneously in tied-off loops of the rat ileum and colon in vivo. (1) In the ileal loops iloprost had no effect on water and ion transfer neither by intraluminal, nor intraaortal or intravenous application. (2) In the colonic loops only intraaortal bolus application of the high dose of 500 micrograms iloprost significantly decreased net water, sodium and chloride absorption, but did not induce net secretion. (3) Inhibition of endogenous prostaglandin synthesis by indomethacin did not change net water and electrolyte transfer in the ileum and colon. (4) Under this pretreatment i.v.-application of 100 micrograms iloprost, ineffe…

Intestinal filtration as a consequence of increased mucosal hydraulic permeability

1980

Two mechanisms have been proposed to explain the secretory action of laxative compounds in the intestine: 1. increase of the intracellular amount of cyclic adenosine monophosphate due to stimulation of the adenylate cyclase system and 2. inhibition of intestinal transfer processes, in particular the Na,K-ATPase activated sodium absorption. In a set of in vivo and in vitro experiments in rat colon it could be demonstrated that dihydroxy bile acids (deoxycholate) and diphenolic laxatives (oxyphenisatin) enhance the hydraulic permeability of the mucosal tissue. The permeability changes take place--and there is good experimental evidence--at the zonulae occludentes which bind the epithelial cel…

Vascular Dysfunction and Oxidative Stress in Diabetic Rats - Comparison of Beneficial Effects of AT1- Receptor Blockade, Calcium Antagonist, or Combi…

2013

Adenosine activates a potassium conductance in guinea-pig atrial heart muscle.

1983

Adenosine shortens the action potential and diminishes the force of contraction in guinea-pig left atria. These effects may be brought about by the activation of a potassium conductance. This assumption is supported by voltage clamp and 42K release experiments.

Relaxation by Calcium Antagonists of Potassium-contracted Trachea from Normal and Sensitized Guinea-pigs: Influence of Epithelium and the Surface of …

1993

Abstract A technique by which drug access was restricted to either the mucosal or the adventitial surface of tracheal rings, isolated from normal (unsensitized) or sensitized guinea-pigs, was used to study the role of the epithelium in the relaxation produced by calcium antagonists (verapamil, nifedipine, cinnarizine and flunarizine) of K+-induced contraction. In trachea from normal guinea-pigs, the relaxation to verapamil for unrestricted or mucosal drug entry was reduced in the absence of epithelium, whereas the relaxation produced by nifedipine, cinnarizine or flunarizine was unchanged. In sensitized trachea, the relaxation elicited by the calcium antagonists tested was similar in intact…

Isolated human chorionic vascular reactivity: Technical considerations for fresh preparations

1998

1. 1. Sixty chorionic vascular rings from normal term placentas were immersed in an organ bath for isometric tension recording to study (A) the contractile response to 120 mM of potassium chloride (KCI) after adjustment and equilibration to 1–5 g of passive tension; and (B) the concentration-response curve to KCI after adjustment and equilibration to the optimal passive tension. 2. 2. Adjustment to 4 g of passive tension elicited the maximal (P<0.007) and the latest (P<0.006) KCl-induced contraction among arterial rings. Venous rings showed the greatest contraction when adjusted to 3 g, but the differences were not significant except when compared to 1 g of passive tension (P<0.03). 3. 3. T…

Über das Verhalten von glatter Muskulatur während Kalium-Verarmung und -Akkumulation

1961

The isolated rat uterus looses potassium in potassium-free Tyrode. During this process, the muscle is more easily excitable, and a slowly developing contracture is produced. If potassium is then made available, the muscle relaxes rapidly and spontaneous contractions temporarely cease.

2015

Neuropsychological group study methodology is considered one of the primary methods to further understanding of the organisation of frontal ‘executive’ functions. Typically, patients with frontal lesions caused by stroke or tumours have been grouped together to obtain sufficient power. However, it has been debated whether it is methodologically appropriate to group together patients with neurological lesions of different aetiologies. Despite this debate, very few studies have directly compared the performance of patients with different neurological aetiologies on neuropsychological measures. The few that did included patients with both anterior and posterior lesions. We present the first co…

2014

Bipolar disorder is characterized by a functional imbalance between hyperactive ventral/limbic areas and hypoactive dorsal/cognitive brain regions potentially contributing to affective and cognitive symptoms. Resting-state studies in bipolar disorder have identified abnormal functional connectivity between these brain regions. However, most of these studies used a seed-based approach, thus restricting the number of regions that were analyzed. Using data-driven approaches, researchers identified resting state networks whose spatial maps overlap with frontolimbic areas such as the default mode network, the frontoparietal networks, the salient network, and the meso/paralimbic network. These ne…

Motor and cognitive growth following a Football Training Program

2015

Football may be a physical and sport activities able to improve motor and cognitive growth in children. Therefore the aim of this study was to assess whether a Football Training Program taken over 6 months would improve motor and cognitive performances in children. Motor skills concerned coordinative skills, running and explosive legs strength. Cognitive abilities involved visual discrimination times and visual selective attention times.Forty-six children with chronological age of ~9.10 years, were divided into two groups: Group 1 (n=24) attended a Football Exercise Program and Group 2 (n=22) was composed of sedentary children.Their abilities were measured by a battery of tests including mo…