Circulatory effects evoded by 'physiological' increases of arterial osmolality.
The effects of moderate arterial hyperosmolality (+20 mOsm/kg H2O), produced by short term intravenous hypertonic infusion, on vascular resistance in skin, skeletal muscle, intestine, and kidney were analyzed in the anesthetized cat. Vascular resistance decreased in all four regions in response to the hypertonicity both before and after regional sympathectomy and the effects were not significantly altered by beta-adreno-ceptor blockade. Arterial blood pressure rose during the hypertonic infusion despite the decreased vascular resistance and an unchanged heart rate, indicating an increased stroke volume and cardiac output. Similar increases of arterial osmolality are known to occur in heavy exercise and in hemorrhage. The present results may therefore suggest that blood borne hyperosmolality is a factor which can contribute to the overall cardiovascular adjustments in these situations.
D000818:Animals; D001794:Blood Pressure; D002415:Cats; D005947:Glucose / Q000494:pharmacology; D006614:Hindlimb / Q000098:blood supply; D006982:Hypertonic Solutions / Q000494:pharmacology; D007583:Jejunum / Q000098:blood supply; D007668:Kidney / Q000098:blood supply; D009132:Muscles / Q000098:blood supply; D009994:Osmolar Concentration; D011433:Propranolol / Q000494:pharmacology; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply; D013395:Sucrose / Q000494:pharmacology; D014655:Vascular Resistance / Q000187:drug effects; D014994:Xylose / Q000494:pharmacology
D006982:Hypertonic Solutions; D013395:Sucrose; D011433:Propranolol; D014994:Xylose; D005947:Glucose