Cardiovascular hyporesponsiveness to norepinephrine, propranolol and nitroglycerin in portal‐hypertensive and aged rats
John Polio, Cornel C. Sieber, Emanuel Lerne, Roberto J. Groszmann – 1 July 1993 – Most studies testing vasoactive agents in portalhypertensive rats have been performed in young animals. To assess age‐related changes in hemodynamic responses to adrenergic stimuli, we examined (a) responsiveness to norepinephrine (0.14 to 12.0 μg ˙ kg−1 ˙ min−1) in young (3‐mo‐old) and aged (9‐mo‐old) sham‐operated and portal‐hypertensive rats and (b) response to propranolol (2 and 10 mg ˙ kg−1 body wt), nitroglycerin (3.6 mg ˙ kg−1 ˙ min−1) or saline solution in aged portal‐hypertensive rats.