title: Sialic acid reduction in the saliva of streptozotocin induced diabetic rats.
abstract: OBJECTIVE
  Diabetes causes changes in the salivary glands and in the composition of saliva, as well as symptoms such as dry mouth and hyposalivation. Therefore, this study aimed at investigating changes in salivary secretion and composition, in response to parasympathetic stimuli, in diabetic rats induced with streptozotocin.
  
  
  METHODS
  Diabetes was induced by a single intraperitoneal injection of streptozotocin. Thirty days after diabetes induction, the animals were anaesthetized and salivation was stimulated by an intraperitoneal injection of Pilocarpine (0.6mg/kg body weight) dissolved in distilled water. Saliva was collected for 40min and immediately stored at -80°C until analysis. The salivary flow rate, amount of total protein, amylase and peroxidase activities, and free and total sialic acid contents were measured.
  
  
  RESULTS
  Salivary flow rate was reduced in the diabetic group (p<0.05). Moreover, increases in total protein amount and in amylase and peroxidase activities were observed in diabetic animals. No difference was observed for free sialic acid content between groups. On the other hand, a significantly decrease in the total sialic acid content was observed in the diabetic group (p<0.05).
  
  
  CONCLUSIONS
  Our findings suggest that a decrease in sialic acid in the saliva of diabetic animals can be related to xerostomia reported by diabetic patients. However, further clinical trials are needed to verify if the decrease in sialic acid also occurs in human saliva.
authors.affiliation: Departamento de Materiais Dentários, Faculdade de Odontologia, Universidade de São Paulo (USP), Av. Prof. Lineu Prestes 2227, São Paulo, SP, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Romero
authors.forename: Flávia Kazue
authors.initials: FK
authors.lastname: Ibuki
authors.forename: Fernando Neves
authors.initials: FN
authors.lastname: Nogueira
mesh_terms: D000681:Amylases / Q000032:analysis; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D018721:Muscarinic Agonists / Q000494:pharmacology; D019158:N-Acetylneuraminic Acid / Q000032:analysis*; D010544:Peroxidases / Q000032:analysis; D010862:Pilocarpine / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000032:analysis; D012472:Salivation / Q000187:drug effects; D012636:Secretory Rate / Q000502:physiology; D013053:Spectrophotometry; D013311:Streptozocin
chemical_list: D018721:Muscarinic Agonists; D012471:Salivary Proteins and Peptides; D010862:Pilocarpine; D013311:Streptozocin; D010544:Peroxidases; D000681:Amylases; D019158:N-Acetylneuraminic Acid