[Developmental changes in protein secretion in rat whole saliva].
Environmental conditions in the oral cavity may modulate the morphological and functional changes during the developmental process in the tissue. Saliva is one of the important factors among them. The purpose of this study is to investigate the proportional changes in the salivary proteins in accordance with the development. Male Wistar-strain rats were maintained from 3 to 12 weeks of age and once a week mixed saliva was collected from the oral cavity for 10 minutes after an intraperitoneal pilocarpine injection under anaesthesia. Salivary proteins were separated by SDS-polyacrylamide gel electrophoresis and silver-stained. The densitometric percentages of the stained protein bands were compared between samples of different weeks. The amount of total protein secretion increased with age, whereas the changes in the proportion of various proteins were inconsistent. Increase or decrease was found in the proportion of several protein components. The result indicated quantitative changes in the salivary protein composition in the developmental stage. A prominent increase of a protein band having an apparent molecular weight of 35 Kd was detected. This protein was identified as DNase I by its N-terminal amino acid sequence.
Katano
H
H
Department of Pedodontics, School of Dentistry, Tokyo Medical and Dental University.
D000375:Aging / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D003850:Deoxyribonuclease I / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D008969:Molecular Sequence Data; D011506:Proteins / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D012463:Saliva / Q000737:chemistry*
D011506:Proteins; D003850:Deoxyribonuclease I