EFFECTS OF THE BETA-ADRENOCEPTOR ANTAGONISTS ATENOLOL AND PROPRANOLOLON HUMAN PAROTID AND SUBMANDIBULAR-SUBLINGUAL SALIVARY SECRETION

The aim of the study was to evaluate the effects of a beta(1)-selectiv e (atenolol 50 mg q.d.) and a non-selective (propranolol 80 mg b.i.d.) beta-adrenoceptor antagonist on human stimulated parotid and submandi bular-sublingual (SM-SL) gland secretion. A randomized double-blind, p lacebo-controlled cross-over (''Latin square'') design was used in 19 healthy male volunteers. Stimulated parotid and SM-SL saliva were samp led immediately before and 7 days af ter the start of each treatment p eriod. Stimulation of salivary secretion was achieved by use of a 3% c itric acid solution. Plasma concentrations of propranolol and atenolol were determined from blood samples. The salivary secretion of both gl ands was assessed for flow rate, amylase, lysozyme, and salivary perox idase activity and for concentrations of total protein, hexosamine, si alic acid, Ca2+, Cl-, K+, Mg2+, Na+, and PO43-. In both parotid and SM -SL secretions, the total protein and phosphate concentrations and amy lase activity were significantly decreased during the two active treat ment periods. In SM-SL gland secretion, there were significant changes in potassium and calcium concentrations during active treatment as co mpared with baseline, with potassium showing a decreased-and calcium a n increased concentration. During atenolol treatment, salivary peroxid ase activity decreased significantly in SM-SL secretion. In parotid se cretion, the hexosamine/total protein ratio decreased and the sialic a cid/hexosamine ratio increased during atenolol treatment, which may in dicate an effect on protein synthesis. No significant effects on saliv ary secretion rates were disclosed.