Background: The purpose of this study was to determine whether a high-resolution solid-state catheter system could detect regional pressure changes within the antrum and pylorus in response to CCK-octapeptide.
Methods: Subjects received a 30 min infusion of CCK-octapeptide at either 0.02 or 0.06 microg kg(-1) h(-1).
Results: Five males and two females were studied. Mean antral pressure during phase I MMC increased from 5.3 +/- 2.1 to 9.9 +/- 2.4 mmHg (P = 0.028) after infusion. At the pylorus, only the 0.06 microg kg(-1) h(-1) dose increased tonic pressure (8.8 +/- 1.4 to 17.6 +/- 2.0 mmHg; P = 0.01) as compared with the 0.02 microg kg(-1) h(-1) dose (4.7 +/- 0.7 to 7.3 +/- 0.4 mmHg; P = NS). The peak pressure of pyloric phasic pressure waves was 153 +/- 28.4 mmHg and their frequency was 4.9 +/- 1.1 contractions min(-1).
Conclusions: CCK-octapeptide elicits both tonic and phasic activity of the pyloric sphincter. The contractile response to a dose of 0.06 mug kg(-1) h(-1) is greater than the response to 0.02 mug kg(-1) h(-1).