ALTERATION OF RAT SUBMANDIBULARY GLAND SECRETION OF PROTEIN, CALCIUM AND N-ACETPL-BETA-D-GLUCOSAMINIDASE ACTIVITY BY LEAD

1. Effects of various doses of long-term lead treatment (0.01%, 0.04% and 0.05%) on rat submandibular saliva were investigated in this study . 2. Both submandibular ducts were cannulated intraorally with polyeth ylene tubes and saliva was collected from anesthetized lead treated an d control rats using pilocarpine as secretagogue. 3. Saliva protein co ncentration was found to be reduced in lead (0.04%) and (0.05%) treate d groups. 4. Saliva calcium concentration had a significant reduction only in the lead (0.05%)-treated group. 5. The secretion of the lysoso mal enzyme, N-acetyl-beta-D-glucosaminidase (NAG) in saliva de creased significantly in the lead (0.04%)- and (0.05)-treated groups. Specifi c activity of the enzyme showed an increase in these treated groups. 6 . Good correlations were found between saliva protein concentration an d NAG activity, saliva protein and calcium concentrations and calcium concentration and NAG activity. 7. There was a correlation between blo od and submandibular saliva lead levels, and the saliva/blood ratio wa s approximately constant for all treated groups.8. With respect to the ability of lead to substitute for calcium in several intracellular re gulatory events, explanation for these alterations in submandibular sa liva composition can be made. (C) 1997 Elsevier Science Inc.