Effect of a model of canine jejunoileal orthotopic autotransplantation on jejunal and ileal transport of water and electrolytes

Abstract

Canine jejunoileal transplantation induces an early profuse watery diarrhea of uncertain etiology. Our aim was to determine the temporal effects of a canine model of jejunoileal autotransplantation (a model devoid of confounding effects of ischemia-reperfusion or immune rejection) on basal jejunal and ileal absorption of water and electrolytes to determine if impaired absorption is responsible for the diarrhea. Our hypothesis was that net absorption of water and electrolytes in an enterically isolated loop would decrease after jejunoileal transplantation. Four groups of dogs (N > or = 6) were prepared with 80-cm modified Thiry-Vella loops: group I, neurally intact jejunum; group II, autotransplanted jejunum; group III, neurally intact ileum; and group IV, autotransplanted ileum. The loops were perfused for 3 hr with 150 mM NaCl at 3 ml/min under fasted conditions; transit time through the loop was determined by bolus of a nonabsorbable marker. Dogs were studied on three separate days at one, two, eight, and nine weeks postoperatively. Net absorptive fluxes of water and electrolytes and transit times were similar (P > 0.05) between neurally intact and autotransplant groups (group I vs II and group III vs IV) at each time point. Ileal loops absorbed more than jejunal loops, and transit was slower in ileal loops (each P < 0.05). Our findings suggest that, despite the obligate disruption of extrinsic innervation, enteric (intrinsic) neural continuity, and lymphatic drainage that accompanies this canine model of jejunoileal autotransplantation, net basal absorptive function of water and electrolytes during the fasted state was not decreased nor was transit altered either in jejunum or ileum.(ABSTRACT TRUNCATED AT 250 WORDS)

Splanchnic Circulation Is a Critical Neural Target in Angiotensin II Salt Hypertension in Rats

“…55 Experimental evidence also indicates that the chronic extrinsic denervation of the small intestine does not affect net intestinal absorption of water and electrolytes. [55][56][57][58][59][60][61][62][63][64][65][66][67] We have also shown that CGx does not affect Na ϩ intake in rats fed 2% NaCl. 68 The exact hemodynamic mechanism by which CGx affects Ang II salt hypertension is still not completely clear and needs to be investigated further by chronic instrumentation of rats for measurements of cardiac output and total peripheral resistance determination.…”

The Current State of Intestinal Transplantation

“…This finding is associated with rejection and frequently mandates augmented immunosuppression. However, some cases remain of unclear etiology, and detailed basic investigation in the past implicated altered motility patterns, denervation with altered sympathetic tone, or other factors (33,34). Recent clinical investigation suggests that novel and specific pathogens not described after other solid-organ transplants may infect the transplanted intestinal allograft.…”

Enteric Physiology of the Transplanted Gut: Absorption and Motility

“…Net absorption has also been evaluated in large-animal models in vivo. Sarr and colleagues [23,[31][32][33][34] explored this topic in-depth in a canine model of jejunoileal auto transplantation devoid of immune effects or ischemia/ reperfusion injury [9], Although no significant differences were noted in net absorption of water and electrolytes in entericallv isolated intestinal loops (as compared with controls), when studied in the in situ jejunum [33] and in the in situ ileum [34], net absorption was decreased 2 weeks after surgery, but returned toward normal by 8 weeks postoperatively, coinciding with the time the diar rhea resolved. Similar results were noted by Dennison et al [35] and Collin et al [36] in the ileum.…”