Stretch-Dependent Effects
نویسندگان
چکیده
Atrial distension, which stimulates atrial natriuretic peptide secretion by atrial myocytes, also stretches nonmuscle cells. In a noncontracting in vitro preparation of combined right and left atria we demonstrated by electron microscopy that, at 37°C, transition from zero pressure to a physiological distending pressure of 5.1 mm Hg rapidly rendered atrial endocardial endothelium permeable to the macromolecular probes horseradish peroxidase (HRP; Mr, =40,000) and wheat germ agglutinin-HRP (Mr, =70,000); each probe was introduced at the atrial cavitary endocardial surface. Stretch-dependent permeabilization was also demonstrable in spontaneously contracting atria, was reversed by removing the distending pressure, and
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