Objective: Analyze the morphological and biochemical changes on the parotid gland of young rats maintained on liquid diet. Methods: Thirty animals, 35 days old, were randomly divided into 2 groups. The control group (CG) received laboratory chow while the experimental group (EG) received liquid diet. The liquid diet was prepared daily and offered ad libidum. The animals were killed after 1, 3, 8, 15 and 30 days. The glands were removed, weighted and prepared for ultrastructural TEM assessment for the morphological features. Bradford method for total protein analysis and Bernfeld amylase activity assays were employed. The Fisher's PLSD test was used to detect the presence of a significant difference between specific pairs of mean of total protein and amylase activity among different experimental periods. Results: No statistical differences were found when the weight of rats and glands from CG and EG were compared, although ultrastructural analysis showed an increase of the secretory granules number as well as an expansion of rough endoplasmic reticulum for the EG animals during the experimental periods of 8, 15 and 30 days. Concerning the biochemical data, the amount of total protein (CG: 8,70 mg/ml; EG: 10,09 mg/ml) and amylase activity (CG: 1,149 U/g; EG: 1,358 U/g) were statistically higher in the EG animals at 8 and 15 experimental periods respectively (p<0,05). At 30 days, it was found that both total protein (CG: 3,89 mg/ml; EG: 10,05 mg/ml) and amylase activity (CG: 0,694 U/g; EG: 2,140 U/g) were increased (p<0,05). Conclusions: The parotid glands of growing rats have different response from that described in the literature for adult animals under the same experimental conditions. Ultrastructural changes on rat parotid gland cells occurred at the same periods in which the amylase activity and the total protein content showed the highest values.

Back to the Salivary Research Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

Top Level Search