IG vs ID Bitter Administration
Condition: Obesity
Study type: Interventional
Phase: Phase 4

Summary: 
      We want to investigate whether bitter compounds, denatonium benzoate and quinine
      hydrochloride, have a distinct effect on gastrointestinal hormone release after infusion into
      the stomach or duodenum. Furthermore, we want to observe an effect on hunger sensations and
      hedonic food intake. Moreover, we suggest somatostatin as a driving factor for decreased
      motilin and ghrelin release after intragastric administration.
    

Detailed description: 
      Intragastric administration of the bitter tastants denatonium benzoate (DB) or quinine
      hydrochloride (QHCl) decreases orexigenic hormone levels, and reduces hunger sensations.
      Contradictory, in vitro studies on human gastric and duodenal tissue showed that DB exposure
      increased motilin and octanoylated ghrelin levels. DB stimulated somatostatin (SST) release,
      which is an inhibiting paracrine hormone. We hypothesized that the reduction in hunger
      ratings and hormone levels is stronger after intragastric compared to intraduodenal
      administration, and that these differences are mediated by differential SST release. Fourteen
      healthy female volunteers participated in a randomized, placebo-controlled crossover study.
      After an overnight fast, DB (1 µmol/kg), QHCl (10 µmol/kg) or placebo were given intragastric
      or intraduodenal via a feeding tube. Blood samples were taken at regular time points to
      obtain the hormonal release. Hunger was rated at the same points on a 100 mm visual analog
      scale (VAS). Ad libitum milkshake intake was assessed at the end of the experiment and taste
      was scored on a VAS.
    

Intervention name(s): Intragastric quinine hydrochloride; Intragastric denatonium benzoate; Intragastric placebo; Intraduodenal quinine hydrochloride; Intraduodenal denatonium benzoate; Intraduodenal placebo
Intervention type(s): Drug; Drug; Drug; Drug; Drug; Drug
Intervention description(s): A nasogastric feeding tube was positioned into the stomach, and checked with a pH strip. 10 µmol of quinine hydrochloride per kg body weight was administrated into the stomach.; A nasogastric feeding tube was positioned into the stomach, and checked with a pH strip. 1 µmol of denatonium benzoate per kg body weight was administrated into the stomach.; A nasogastric feeding tube was positioned into the stomach, and checked with a pH strip. 0.1 ml of water (placebo) per kg body weight was administrated into the stomach.; A nasogastric feeding tube was positioned into the duodenum, and checked with fluoroscopy. 10 µmol of quinine hydrochloride per kg body weight was administrated into the duodenum.; A nasogastric feeding tube was positioned into the duodenum, and checked with fluoroscopy. 1 µmol of denatonium benzoate per kg body weight was administrated into the duodenum.; A nasogastric feeding tube was positioned into the duodenum, and checked with fluoroscopy. 0.1 ml of water (placebo) per kg body weight was administrated into the duodenum.
Other intervention name(s): IG QHCl; IG DB; IG PLC; ID QHCl; IG DB; ID PLC
Intervention MeSH terms: Quinine; Denatonium
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Basic Science
Keywords: Bitter; Motilin; Ghrelin; CCK; GLP-1; SST; Denatonium benzoate; Quinine hydrochloride