title: Enhancement of carbachol-induced amylase secretion in parotid glands from rats with experimental periodontitis.
abstract: OBJECTIVE
  In a previous study we observed that parotid glands from rats with experimental periodontitis showed an increase in basal amylase release as a result of an increase in cAMP accumulation induced by PGE(2) production. The aim of this work was to study whether this change in amylase release influences the secretory effect of carbachol.
  
  
  METHODS
  Experimental periodontitis was induced through placing a black thread around the cervix of the two lower first molars. Experiments were done 22 days after ligature induced periodontitis. Amylase release was evaluated in vitro and determined using a colorimetric method which uses starch as substrate.
  
  
  RESULTS
  The effect of carbachol was increased in parotid glands from periodontitis rats. The effect of 10(-6)M carbachol was inhibited by 4-DAMP (10(-6)M), U-73122 (5 × 10(-6)M) and trifluoperazine (5 × 10(-6)M) in both groups. No changes were observed in the binding sites and affinity in parotid membranes from rats with experimental periodontitis. The inhibition of the adenylyl cyclase and the cyclooxygenase induced a right shift of the carbachol concentration-response curve in periodontitis group whilst the opposite effect was observed in control group in the presence of db-cAMP and PGE(2).
  
  
  CONCLUSIONS
  Parotid glands from rats with experimental periodontitis release more amylase in response to carbachol suggesting an interaction between Ca(2+) and cAMP in the fusion/exocytosis step of secretory vesicles.
authors: Pharmacology Unit, School of Dentistry, University of Buenos Aires, Marcelo T. de Alvear 2142 (1122AAH), Buenos Aires, Argentina.
authors: Valeria
authors: V
authors: Miozza
authors: Gabriel
authors: G
authors: Sánchez
authors: Leonor
authors: L
authors: Sterin-Borda
authors: Lucila
authors: L
authors: Busch
mesh_terms: D000681:Amylases / Q000096:biosynthesis*; D000704:Analysis of Variance; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D003124:Colorimetry / Q000379:methods; D000242:Cyclic AMP / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects*; D008297:Male; D010306:Parotid Gland / Q000187:drug effects / Q000201:enzymology*; D010518:Periodontitis / Q000201:enzymology* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002217:Carbachol; D000242:Cyclic AMP; D000681:Amylases