Inhibition of gastrointestinal mucosal glycoprotein synthesis by the β-adrenergic blocking drug, practolol

Abstract

The effect of administration of practolol and other β-blocking agents on gastrointestinal mucosal glycoprotein synthesis was studied in the rat. Practolol, at a dose of 50 mg/kg, inhibited the incorporation of N-acetylglucosamine into gastric mucosal glycoproteins, while acebutolol, atenolol, pronethalol and propranolol had no inhibitory effect, even at a dose of 200 mg/kg. In addition, practolol inhibited the incorporation of N-acetylneuraminic acid, D-fucose and L-serine into gastric mucosal glycoproteins, while the other β-blocking agents had no effect. Administration of practolol caused no significant change in the rate of incorporation of glycoprotein precursors into intestinal mucosal glycoproteins. These results indicate that of the β-blocking drugs studied, inhibition of glycoprotein synthesis is associated only with practolol and is independent of its β-blocking effect.