Acta Vet. Brno 2008, 77: 489-501

https://doi.org/10.2754/avb200877040489

Effects of Various Doses of Cholecystokinin Octapeptide and Cerulein on Antral Slow-Wave Frequency and Amplitude in Conscious Sheep

K. W. Romański

Department of Animal Physiology, Veterinary School, Wrocław University of Environmental and Life Sciences, Wrocław, Poland

Received November 2, 2006
Accepted July 7, 2008

It is suspected that cholecystokinin (CCK) might affect antral slow-wave frequency and amplitude, but in sheep this problem is virtually unknown. Therefore the myoelectric activity was continuously recorded before and after intravenous administration of 0.15 M NaCl or CCK peptides in adult rams, equipped with platinum bipolar electrodes in the abomasal antrum, duodenum, and jejunum. CCK octapeptide (CCK-OP) was given to five rams at doses of 17.5, 175, or 1750 pmol/ kg and cerulein was administered to six rams at doses of 0.735, 7.35, or 73.5 pmol/kg of body weight. Each dose was infused to fasted or non-fasted animals for 30, 60, 120, or 300 s during phase 1, 2a or 2b (the less or more intense) of the migrating myoelectric complex (MMC). The 300-sec infusion of the moderate CCK-OP dose during the less intense or more intense phase 2b of the MMC increased the antral slow-wave amplitude from 79 ± 7 to 124 ± 26 μV (p < 0.01) and from 82 ± 8 to 175 ± 40 μV (p < 0.001), respectively. The 300-sec infusion of the highest CCK-OP dose under the same conditions increased antral slow-wave amplitude from 79 ± 6 to 121 ± 24 μV (p < 0.05) and from 84 ± 9 to 138 ± 27 μV (p < 0.01), respectively. Administration of the moderate dose of CCK for 120 s in the course of the less or more intense phase 2b of the MMC increased antral slow-wave frequency from 6.1 ± 0.2 to 6.6 ± 0.4 cpm (N.S.) and from 6.1 ± 0.3 to 6.8 ± 0.4 cpm (p < 0.05), respectively. Administration of the highest dose of CCK-OP for 120 s in the course of the less or more intense phase 2b of the MMC increased the antral slow-wave frequency from 6.2 ± 0.3 to 7.2 ± 0.4 (p < 0.05) and from 6.0 ± 0.3 to 7.8 ± 0.6 cpm (p < 0.001), respectively. It is concluded that CCK in physiological and putatively pharmacological doses can affect the slow-wave frequency and amplitude in sheep related in part to the small-intestinal MMC phase and the intensity of the antral motor activity.