Propulsive Gastrointestinal Motility after Controlled Bleeding in the Rat

Abstract

The gastric evacuation and propulsive function of the small intestine were analysed after bleedings of different magnitudes in 464 rats. A quantitative method that also allows comparisons between these functions was used. The amount of blood removed varied between 4 and 6 ml, corresponding to 22 and 33 per cent of the total blood volume, respectively. Recordings were made immediately after and 5 hours after the bleeding. Bleeding from non-heparinized animals allowed conclusive recordings of the motility conditions; it was concluded that both the gastric evacuation and, in particular, the propulsive motility of the small intestine were inhibited by the bleeding —the larger the amount of blood removed, the greater the inhibition. The small intestine was considered to be an organ with great tolerance to anoxia of different origins. Functions such as motility and absorption can be retained up to a stage very close to that of irreversible shock.

Key-words:

• Bloodletting
• blood volume
• gastrointestinal motility
• gastrointestinal system
• rat