Jejunal myoelectrical activity in the conscious neonatal pig.

Abstract

The purpose of this study was to define and quantify patterns of normal jejunal myoelectrical activity in the conscious neonatal pig. Twelve 3-day-old piglets were obtained from a local herd. At 7 days of age four bipolar Ag-AgCl electrodes were surgically implanted at 5 cm intervals on the jejunum. Piglets were divided into fed (n = 7) and fasted (n = 5) groups and a minimum of four daily recordings were made from each pig between 7 and 14 days of age. Slow wave and spike activity were seen in all animals. Slow waves occurred at a frequency of 17.0 +/- 0.3 cycles/min (c.p.m.) in fed and 16.8 +/- 0.2 c.p.m. in fasted piglets. Spike activity predominated, occurring in characteristic migrating myoelectrical complexes (m.m.c.s.) and occupying 79% of the recording time in fed and 73% in fasted piglets (P less than 0.05). The activity front (phase 3) of the m.m.c. recurred every 47.7 +/- 2.4 min in fed, and 50.9 +/- 2.3 min in fasted piglets. The m.m.c. periodicity in both groups was irregular, with a range of 4-145 min in fed, and 8-104 min in fasted piglets. Activity fronts lasted 4.8 +/- 0.1 min in fed and 4.4 +/- 0.1 min in fasted piglets. All piglets demonstrated intense, short (2.5-5.0 s), distinct bursts of intense spike activity (migrating action potential complexes, m.a.p.c.s.). These were rapidly conducted in an aboral direction at a velocity of 1.8 cm/s in fed, and 0.8 cm/s in fasted piglets (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)