title: Gastric emptying of liquids is delayed by co-ingesting solids: a study using salivary paracetamol concentrations.
abstract: BACKGROUND
  Paracetamol concentrations in plasma, a frequently used index of gastric emptying (GE) of liquids, are closely correlated with those in saliva. GE of liquids is delayed by co-ingesting solids. No researchers have used salivary paracetamol concentrations to show this phenomenon. The aim of this study was to elucidate whether salivary paracetamol concentrations can detect the food-induced delay in liquid GE.
  
  
  METHODS
  Paracetamol absorption was measured twice in five healthy male volunteers. Following an overnight fast, they received 10 mg/kg paracetamol in 200 ml water alone on one occasion, and received this solution after consuming a 400 kcal-containing cookie on another occasion. After thorough rinsing of the month, 1 ml saliva was obtained, simultaneously with 2 ml blood, at 0, 0.25, 0.5, 0.75, 1.0, 2.0, 3.0, 4.0, and 6.0 h after paracetamol intake. The peak concentration (C(max)), the time to C(max) (t(max)), the area under the curve (AUC), and C(max)/AUC in plasma were calculated. Salivary C(max) and t(max) were also determined.
  
  
  RESULTS
  Plasma C(max) and AUC were not significantly different between the two occasions. In contrast, significant differences in plasma t(max) and C(max)/AUC ( P < 0.05) established the food-induced delay in GE. Salivary t(max) could detect the delayed GE, whereas salivary C(max) could not.
  
  
  CONCLUSIONS
  Salivary t(max) can document the solid meal-induced delay in liquid GE.
authors.affiliation: Department of Internal Medicine, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Sanaka
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kuyama
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimomura
authors.forename: Jin Feng
authors.initials: JF
authors.lastname: Qi
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Okamura
authors.forename: Yu
authors.initials: Y
authors.lastname: Hao
authors.forename: Chen
authors.initials: C
authors.lastname: Jainguo
authors.forename: Satoru
authors.initials: S
authors.lastname: Mineshita
mesh_terms: D000082:Acetaminophen / Q000032:analysis / Q000097:blood; D000328:Adult; D004326:Drinking; D004435:Eating; D005746:Gastric Emptying; D006801:Humans; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry*
chemical_list: D000082:Acetaminophen