Validation of octanoate breath test for measuring gastric emptying in rats

Ingrid Demedts, Christophe Vanormelingen, Hubert Van Billoen, Tim Vanuytsel, Ricard Farré, Tatsuhiro Masaoka, Alfons Verbruggen, Kristien Verbeke, Pieter Vanden Berghe, Jan Tack

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Background/Aims: Lack of simple and repeatable tests hampers gastric emptying studies in rats. The aim of this study was to adapt the 14C-octanoate solid gastric emptying breath test for application in rats, and to validate it against radioscintigraphic method. Methods After ingestion of a meal containing 3 mCi 99mTc and 2 μCi 14C-octanoate, 23 male Wistar rats were placed on a gamma cam - era in a airflow container. Scintigraphic images were taken at regular intervals. The amount of 14CO2 in a regularly replaced hyamine hydroxide solution, capturing CO2 in the outflow air, was counted using liquid scintillation spectrometry. 99mTc gastric retention curves and 14CO2-excretion curves were fitted to their respective data. Three rats underwent the same procedures after administration of atropine. Results Overall Tr10% (time at which 10% of the original amount of 99mTc remained in the stomach) was 355 ± 64 minutes; Te90* (time at which 90% of total amount of 14CO2 was excreted) was 325 ± 106 minutes. Their correlation coefficient was 0.71, R-square 0.50 and P < 0.005. Tr1/2 (50% of original amount of 99mTc remained) was 124 ± 28 minutes; Te1/2 (50% of total amount of 14CO2 excreted) 114 ± 32 minutes. Their correlation coefficient was 0.83 with R-square of 0.69 and P < 0.00005. In 12 immobilized animals correlation was even better: correlation coefficient 0.84; R-square 0.71 and P < 0.001 (Tr10% was 388 ± 117 minutes; Te90* 532 ± 219 minutes; Tr1/2 of 165 ± 54 minutes; Te1/2 of 175 ± 67 minutes). Atropine significantly lengthened all emptying times: 904 ± 307 and 1461 ± 684 minutes for Tr10% and Te90*, respectively; and 432 ± 117 minutes for Tr1/2 and 473 ± 190 minutes for Te1/2. Conclusions We adapted and validated the 14C-octanoate gastric emptying breath test for application in rats.

Original languageEnglish
Pages (from-to)171-178
Number of pages8
JournalJournal of Neurogastroenterology and Motility
Issue number2
Publication statusPublished - 2013 Apr
Externally publishedYes


  • Breath tests
  • C-octanoate
  • Gastric emptying
  • Rats

ASJC Scopus subject areas

  • Clinical Neurology
  • Gastroenterology


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