INSTITUTO DE INVESTIGACIONES EN CIENCIAS DE LA SALUD
Unidad Ejecutora - UE
Functional and proteomic analysis of submandibular saliva in rats exposed to chronic stress by immobilization or constant light
ALTERMAN, A; MATHISON, R; CORONEL, CARLOS E.; STROPPA, MM; FINKELBERG, AB; GALLARA, RV
ARCHIVES OF ORAL BIOLOGY
PERGAMON-ELSEVIER SCIENCE LTD
Lugar: Amsterdam; Año: 2012 vol. 57 p. 663 - 663
Abstract Objective: In this study, we have evaluated the effects of stress on functional and proteomic changes in submandibular saliva of rats. Design: Male adult rats were divided in three groups: IMO (2h/day of immobilization for 7 days), LL (constant light during 20 days), C (unstressed controls submitted to 14h light-10h dark cycle). Body weight, food intake and the dry weight of submandibular glands were registered. Saliva samples collected from anesthetized animals by ip administration of isoproterenol and pilocarpine (5mg/Kg), were assessed for total proteins (TP) and amylase activity, and then subjected to SDS-PAGE electrophoresis. Results: Body weight, food intake and the dry weight of submandibular gland of IMO rats were lower than those of C and LL groups. The salivary volumes secreted by IMO and LL rats, were significantly higher than those in the controls. The TP output (ìg protein/ìg saliva/mg of dry tissue) and amylase activity output (AU/ìg of saliva/mg of dry tissue) in IMO were significantly higher than those in C and LL animals. The electrophoretic pattern of saliva proteins of LL rats, revealed the absence of a protein band of approximately 25 kDa. This band was composed by the common salivary protein-1 and a prolactin-induced protein as identified by Peptide mass fingerprinting. Conclusions: Differences in body weight and food intake between IMO and LL might be attributed to the sort and intensity of stressors stimuli. Changes in the volume of secreted saliva could be a compensatory mechanism in response to stressors. The increase of total proteins and á-amylase activity in IMO could be due to an increase in activity of the sympathetic nervous efferent to the submandibular glands. Decreases in the activity of the sympathetic nerves may have produced the absence of 25kD proteins in LL s amples. Future studies are required to determine the role of constant light on these proteins.