The effect of splanchnic viscera removal upon canine liver regeneration

Abstract

The influence of portal blood factors on canine liver regeneration was studied with graded nonhepatic splanchnic evisceration, coupled with 44 and 72 per cent hepatectomies. In one type of experiment, the pancreas was retained while the rest of the intra-abdominal gastrointestinal tract was removed. In a second variety, total pancreatectomy was performed with preservation of the intra-abdominal organs. In a third kind of experiment, total nonhepatic splanchnic evisceration was performed. Liver regeneration after hepatectomy was decreased by all three kinds of viscera removed as judged by deoxyribonucleic acid synthesis, autoradiography and mitotic index. Pancreatectomy and nonpancreatic splanchnic evisceration caused almost equal decreases in the regenerative response. Total nonhepatic splanchnic evisceration essentially halted regeneration during the first three postoperative days and intraportal infusions of insulin or glucagon, or both together, did not reverse this effect. The decrease in liver membrane bound adenyl cyclase activity and biphasic change in liver cyclic 3', 5' -adenosine monophosphate concentrations normally seen after partial hepatectomy were disrupted after the various eviscerations. Adenyl cyclase activity and cyclic 3', 5' -adenosine monophosphate concentrations tended to be higher than normal in the eviscerated dogs. These observations provide more support for our previously proposed hypothesis that control of liver regeneration is by multiple factors. Pancreatic hormones are important modifiers of this response but, by no means, exercise exclusive control. Other substances of gastrointestinal origin, presumably including hormones and nutrient supply apparently play important specific roles. The volume of portal flow is a secondary and nonspecific, but possibly significant, factor.

Fig. 1

Surgical procedures used in animals submitted to concomitant partial hepatectomy. A.Total pancreatectorny; B.nonhepatic splanchnic evisceration with retained distal colon; C. total nonhepatic splanchnic evisceration and D. nonhepatic splanchnic evisceration with retention of isolated pancreas. G.d.a.. Gastroduodenal artery: L.g.a.. left gastric artery

Fig. 2

Insulin, glucagon-like immunoreactivity, GLI. glucagon-mean ± S.D .-in dogs submitted to complete nonhepatic splanchnic evisceration, open bars. N, and to nonhepatic splanchnic evisceration with retention of distal part of colon, shaded bars, P. These dogs did not undergo partial hepatectomy. Statistical comparison by Student’s t test is to intact fasted dogs.

Fig. 3

Plasma insulin concentrations in normal dogs is shown at left. The center bar shows insulin one day after the evisceration shown in Figure 1B, four dogs, or Figure 1C, three dogs. The right bar shows plasma insulin concentration one day after total pancreatectomy. All values are mean ± S. D. The statistical comparison with Student ’s t test are to the intact dogs. The shaded area represents the minimum concentration detectable for this laboratory.

Fig. 4

Hepatic deoxyribonucleic acid, D.N.A., synthesis following 44 per cent hepatectomy and various eviscerations, mean ± S.D. Comparison using Student’s t test is to intact dogs on same day after 44 per cent hepatectomy. DPM. Disintegrations per minute.

Fig. 5

Hepatic deoxyribonucleic acid. D.N.A. synthesis following 72 per cent hepatectomy and various eviscerations, mean ± S.D. Comparison using Student’s t test is to intact dogs on same day after 72 per cent hepatectomy. DPM. Disintegrations per minute.

Fig. 6

Glucagon stimulated hepatic adenyl cyclase activity following 44 per cent hepatectomy and various eviscerations, mean ± S.D. Comparison using Student’s t test is to intact dogs on same day after 44 percent hepatectomy.

Fig, 7

Glucagon stimulated hepatic adenyl cyclase activity following 72 per cent hepatectomy and various eviscerations, mean ± S.D. Comparison using Student’s t test is to intact dogs on same day after 72 per cent hepatectomy

Fig.8

Hepatic cyclic 3′,5′-adenosine monophosphate following 44 per cent hepatectomy and various eviscerations, mean ± S.D. Comparison using Student’s t test is to intact dogs on same day after 44 per cent hepatectomy.

Fig. 9

Hepatic cyclic 3′, 5′-adenosine monophosphate following 72 per cent hepatectomy and various eviscerations, mean ± S.D. Comparison using Student’s t test is to intact dogs on same day after 72 per cent hepatectomy.