Renal homotransplantation with venous outflow or infusion of antigen into the portal vein of dogs or pigs: Transplantation at portal site

Kidneys were transplanted in mongrel dogs so that renal venous drainage was into the portal system of the hosts. Thirty-one recipients were not treated, 11 were given one dose of 3 mg of azathioprine per kg, and 11 were given 2 mg of azathioprine per day. Survival was not statistically increased compared with that in three comparable series in which renal venous drainage was into the vena cava, nor were the histopathological findings favorably altered in the “portal” kidneys. The injection of semisoluble antigen into the portal vein at the same time as renal transplantation at the caval site, had an effect no different from that if the antigen were given systemically during caval site transplantation. The conclusion that drainage of grafts into the portal vein was not beneficial was reached in 20 pigs evenly divided between the portal and vena caval sites, and in 12 pairs of dog to pig or pig to dog xenografts. Thus, none of these experiments has identified an advantage of antigen delivery into the portal as opposed to the systemic venous system. © 1977 by The Williams & Wilkins Co

Portacaval shunt for glycogen storage disease and hyperlipidaemia.

Complete portacaval shunt was used to treat 10 patients with glycogen storage disease. A favourable effect was noted on body growth and a number of metabolic abnormalities. More recently, continous night feedings with an intermittently placed gastric tube or through a gastrostomy has been shown to be helpful either before or after portacaval shunts. Such alimentation techniques may eliminate the need for shunts in some patients and be of adjuvant benefit in others. Portacaval shunt was also used for three children who had homozygous Type II hyperlipidaemia. Substantial reductions in serum cholesterol concentration were observed, as well as resorption of xanthomas. Reversal of some cardiovascular lesions has been documented. The benefits of portacaval shunt in these disorders is probably due to the change in the hormone climate of the liver and the whole organism brought about by diversion of the hormone-rich splanchnic venous blood around the liver

The influence of portal blood upon lipid metabolism in normal and diabetic dogs and baboons

It has been reported that hyperlipidemia can be alleviated in human beings with an end to side portacaval shunt. Understanding the mechanism of the effect has important implications, including the possibility of devising other ways of lowering serum lipid levels. In this investigation, the influence of splanchnic venous blood on lipid metabolism was evaluated in dogs and baboons by altering the portal venous inflow to all, or portions, of the liver and by measuring the effects on different end points, including the serum lipid concentrations and the rate of hepatic lipid synthesis. In other studies, analyses have been made regarding the effect of alloxan induced insulinopenia and of total pancreatectomy on these processes. The results indicate that the effect of complete portal diversion upon serum lipids is mainly due to diversion of the hormone rich venous return from the upper splanchnic organs, although the bypass of the nutritionally rich blood returning from the intestines may play a secondary role. Therefore, a reduction of hepatic lipid synthesis is an important, although not necessarily the sole, factor in the antilipidemic influence of portacaval shunt. The effects upon synthesis and blood lipids are due more to the diversion of endogenous hormones than to the bypass of intestinal nutrients. The substances in portal venous blood that subserve hepatic lipid metabolism are presumably largely the same as the hepatotrophic factors which have been described before as profoundly affecting hepatic structure, function, and the capacity for regeneration. These portal blood factors are multiple and interrelated, but the single most important one seems to be insulin

The effect of splanchnic viscera removal upon canine liver regeneration

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 partial hepatectomy was disrupted after the various eviscerations. Adenyl cyclase activity and cyclic 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