Atrial Stretch
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. CaracterizaÃÃo das vias neuro-humorais no retarde do esvaziamento gÃstrico de lÃquidos advindo da distensÃo mecÃnica atrial direita em ratos acordados. / Characterization of neuro-humoral pathways involved in delayed gastric emptying of liquids due to mechanical right atrial stretch in awake rats.
Right atrium mechanical stretch (AS) increases gastric motility in anesthetized rats. We aimed to study the effect of AS on gastric emptying (GE) in awake rats and the related neuro-humoral pathways ivolved. Male albino rats (N=361, 250-280g) had a silicone balloon inserted in the right atrium. After 24-h, the central venous pressure (CVP), heart rate (HR) a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/02/2010
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2. A distensÃo mecÃnica atrial direita diminui a complacÃncia gÃstrica em ratos normovolÃmicos anestesiados / The Decreases of Gastric compliance Due do to Rigth Atrial Distension in Normovolemics Anesthetized Rats
GraÃa et al. (2002) observou em ratos que a hipervolemia aumenta o tÃnus gÃstrico, enquanto a hipovolemia o diminuÃa. Resolvemos estudar o efeito do estiramento cardÃaco sobre o tÃnus gÃstrico e os mecanismos neurais envolvidos. Metodologia: Ratos albinos machos (n=82, ~320g), anestesiados, com vasos cervicais canulados para registros hemodinÃmicos e
Publicado em: 2006
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3. Sinalização em miocitos cardiacos submetidos a aumentos de tensão
A variety of stimuli, such as hemodynamic overload, can lead to an increase in mechanical stress on cardiomyocytes that can be compensed by the development of a hypertrophyc phenotype. The hypertrophyc response is characterized by a rapid and coordinate activation of intracellular signaling pathways that regulate gene expression and results in a hypertrophyc
Publicado em: 2004
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4. Block of stretch-activated atrial natriuretic peptide secretion by gadolinium in isolated rat atrium.
1. Isolated superfused rat atrial preparations were used to study the mechanism of stretch-induced atrial natriuretic peptide (ANP) secretion. The stretch of the atrial myocytes was induced by raising the intra-atrial pressure. The secretion rates were analysed by measuring ANP concentrations from the superfusate fractions by radioimmunoassay. 2. The effect
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5. Influence of right atrial stretch and atrial natriuretic factor on rat intestinal fluid content.
1. Studies were made on the effects of right atrial stretch and atrial natriuretic factor (ANF) infusion on fluid movement into the intestinal tract. 2. Stimulation of the atrial volume receptors by inflation of an intracardiac balloon in the conscious, unrestrained rat did not change intestinal fluid content under normovolaemic conditions. 3. When the rat w
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6. Stretch-induced atriopeptin secretion in the isolated rat myocyte and its negative modulation by calcium.
Cellular mechanism(s) regulating atriopeptin secretion and processing by the atrial myocyte are currently unknown. Osmotic stretch of isolated atrial myocytes as well as potassium chloride depolarization were potent stimuli of atriopeptin secretion. Release was potentiated by buffering either extracellular calcium with EGTA or intracellular calcium with the
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7. Manipulation of stretch-induced atriopeptin prohormone release and processing in the perfused rat heart.
Atriopeptin (AP) is stored as the prohormone AP-126 [atrial natriuretic factor-(1-26)] in atrial granules. Cultured atrial myocytes synthesize and release only prohormone into the medium. HPLC analysis of the coronary venous effluent of media from perfused rat hearts subjected to right atrial stretch indicated the presence of the C-terminal mature hormone AP
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8. Extracellular fluid translocation in perfused rabbit atria: implication in control of atrial natriuretic peptide secretion.
1. Transmural transport of 22Na+, 51Cr-EDTA, [3H]inulin and [14C]Dextran (57 kDa) was measured in perfused rabbit atria. The radiolabelled extracellular space (ECS) markers and [14C]Dextran were introduced into the pericardial space or atrial lumen. Atrial volume changes were induced by steps up and down in atrial pressure. 2. Basal rates of transmural trans
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9. Centers involved in the autonomic reflex reactions originating from stretching of the atria.
Stretching the atria in anesthetized dogs produces reflex changes in heart rate, and in cardiac and renal sympathetic nerve activity. Anemic decerebration, cord transection at C4-C5, and severance of vagal or sympathetic cardiac nerves was done to identify the pathways and centers essential for these reflexes. Stretching the right atrium produced an acelerat
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10. Atrial natriuretic factor release during pregnancy in rats.
1. We investigated the control of atrial natriuretic factor (ANF) secretion during pregnancy. 2. Plasma ANF levels were measured in conscious virgin female rats under basal conditions, and after atrial distension with an indwelling balloon catheter. The rats were then mated, and the measurements repeated at 7, 14 and 21 days of pregnancy, and at 1 week postp
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11. Ca2+ influx through stretch-activated cation channels activates maxi K+ channels in porcine endocardial endothelium.
The endocardial endothelium is an important modulator of myocardial function. The present study demonstrates the existence of a stretch-activated Ca(2+)-permeable cation channel and of a Ca(2+)-activated K+ channel in the endocardial endothelium of the porcine right atrium. The stretch-activated channel is permeable for K+, Na+, Ca2+, and Ba2+, with mean con
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12. The Mechanism of Adaptation of Left Atrial Stretch Receptors in Dogs with Chronic Congestive Heart Failure
Chronic congestive heart failure (CHF) was induced in dogs by the construction of an aorto-caval fistula below the level of the renal arteries. Aorto-caval fistula dogs showed signs of CHF which included ascites, hind limb edema, and pulmonary congestion. Ventricular catheterization indicated a significantly higher left ventricular end diastolic pressure and