title: Spontaneously hypertensive rat as experimental model of salivary hypofunction.
abstract: OBJECTIVE
  To analyse the salivary activity in spontaneously hypertensive rats (SHRs) evaluating biochemical parameters of saliva in 4-week-old and 12-week-old animals.
  
  
  METHODS
  Systolic blood pressure (SBP) was recorded by tail plethysmography. The salivary flow rate was stimulated by pilocarpine (SFR). The pH and salivary buffering capacity (SBC) were evaluated with a specific electrode. The concentrations of fluoride ([F(-)]) and calcium ([Ca(++)]) ions were determined using an electrode connected to a calibrated ion analyser. The total protein concentration was determined by Lowry method, and amylase activity by kinetic method. The salivary IgA was determined by enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  The SFR, [F(-)] and [Ca(++)] increased with age in normotensive rats, however no alteration in pH, total protein and IgA was observed between 4 and 12 weeks old Wistar rats. SBC decreased with age in Wistar rats. The SFR was not altered between SHRs in different ages and it was lower in 12 weeks old SHR when compared to Wistar rats. An increase in the protein concentration, and in the amylase activity and [F(-)] was observed with the development of SHR. Unaltered SBC, salivary IgA and [Ca(++)] were observed in 12 weeks old when compared to 4 weeks old SHR. The [Ca(++)] ions were reduced in saliva of SHR than that of Wistar rats at 12 weeks. A lower pH was observed in saliva of Wistar than that of SHR at 12 weeks.
  
  
  CONCLUSIONS
  SHR is an experimental model of salivary hypofunction, the decreased SFR observed in SHR at different ages was associated to salivary biochemical parameter alterations.
authors.affiliation: Department of Pediatrics and Social Dentistry, School of Dentistry of Araçatuba, São Paulo State University, UNESP, SP, Brazil. dcrpicco@gmail.com
authors.forename: Daniele C R
authors.initials: DC
authors.lastname: Picco
authors.forename: Lilian F
authors.initials: LF
authors.lastname: Costa
authors.forename: Alberto C B
authors.initials: AC
authors.lastname: Delbem
authors.forename: Kikue T
authors.initials: KT
authors.lastname: Sassaki
authors.forename: Doris H
authors.initials: DH
authors.lastname: Sumida
authors.forename: Cristina
authors.initials: C
authors.lastname: Antoniali
mesh_terms: D000367:Age Factors; D000681:Amylases / Q000032:analysis; D000704:Analysis of Variance; D000818:Animals; D002118:Calcium / Q000032:analysis; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005459:Fluorides / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007070:Immunoglobulin A / Q000032:analysis; D008297:Male; D010991:Plethysmography; D011506:Proteins / Q000032:analysis; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D012463:Saliva / Q000737:chemistry / Q000378:metabolism*; D014987:Xerostomia / Q000378:metabolism* / Q000503:physiopathology*
chemical_list: D007070:Immunoglobulin A; D011506:Proteins; D000681:Amylases; D005459:Fluorides; D002118:Calcium