Investigations on caffeine passage into the canine gastric juice.
Two caffeine boluses (5 and 10 mg/kg) were i.v. administered to four gastric fistula dogs. Gastric secretion was collected before and during pentagastrin stimulation (1, 2 and 4 micrograms/kg/h). Caffeine concentration in serum and gastric juice was determined by HPLC. Mean serum caffeine concentrations were clearly dose-dependent: 4.88 +/- 0.73 (n = 72) and 10.18 +/- 0.98 mg/l (n = 70). After each bolus, the time course of serum concentration was described by a single exponential, yielding an estimation of caffeine half-life: 310 +/- 46 (n = 9) and 453 +/- 59 min (n = 9), respectively. In both cases the same apparent volume of distribution: 0.87 +/- 0.02 l/kg (n = 9) was found. In gastric juice, caffeine concentration depended on the caffeine dose: 2.51 +/- 2.15 (n = 66) and 6.04 +/- 2.57 mg/l (n = 62); outputs were found to be linearly related to juice output, the slope being controlled by the caffeine dose. It was concluded that caffeine passage into gastric juice was governed by a solvent drag mechanism.
Casoli
P
P
Institut National de la Santé et de la Recherche Médicale, Marseille, France.
Vèrine
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H
D000818:Animals; D002110:Caffeine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D005744:Gastric Acid / Q000378:metabolism; D005750:Gastric Juice / Q000737:chemistry / Q000378:metabolism*; D007275:Injections, Intravenous; D008297:Male; D010418:Pentagastrin / Q000008:administration & dosage
D002110:Caffeine; D010418:Pentagastrin