Effect of chronic ethanol and nicotine consumption on the function and morphology of the salivary glands.

The effect of chronic ethanol and nicotine consumption on the function and the morphology of the salivary glands was studied. In smokers and drinkers there was a significantly reduced flow rate of parotid and submandibular saliva. The protein excretion in both secretions was significantly lowered. A reduced salivary flow rate and a lowered protein output also were found in rats that has been fed a liquid diet containing 36% of total calories as ethanol for 90 days. The parotid glands in these animals showed an impressive fatty degeneration. Additionally there was atrophy of the acinar cells. Rats in which nicotine was administrated orally via the drinking water (100 ml/l) did not show a reduction of salivary flow rate. However, salivary protein excretion was significantly lowered. The parotid glands of these animals showed a swelling of the acinar cells and an increase in the total number of intraacinar secretory granula. Most of these granula were immature light ones containing only small concentrations of glycoprotein, while the number of mature dark granula which contain high concentrations of glycoprotein was drastically reduced. The observed functional and morphological alterations reflect an exhaustion of salivary glands due to a nicotine-mediated chronic secretory stimulation. The results of this study indicate that mainly ethanol and to a lesser extent nicotine after chronic consumption cause severe morphological and functional alterations.