Autonomic system and hypothalamo-hypophyseal-cortico-suprarenal reactions in sheep during duodenal distension

Under general anaesthesia, Ni-chrome electrodes were implanted into the mus cular layer of forestomachs, abomasum, duodenum, coecum and colons of sheep . Duodenal permanent cannula were inserted into gastrointestinal tracts of sheep as well as balloons, which during experimental period (5 min) were fi lled with 40 (RD40) or 80 cm(3) (RD80) of warm water. Shortly after duodena l distensions of different intensities (RD40 and RD80), a drop of spikeburs t frequency (80% and 98% respectively) within 20 to 40 min following termin ation of intestine distension, has been noticed. Simultaneously, a signific ant increase of the plasma cortisol level occurred, The 90-170% increase wa s noticed during the 60 min after RD40, and 267-355% following RD80. in cas e of RD80, even two hours after duodenal distension the level of this hormo ne was over 70% higher in the plasma of experimental animals than in that o f control ones. The decrease of gastric motility, caused by pain connected with duodenal di stension, is not a simple viscero-visceral inhibitory reflex, but a general hypothalamo-hypophyseal-corticoadrenal stress reaction, This means that an imals suffering from visceral pain need rational and humane treatment, incl uding pharmaceutical treatment, to minimize suffering.