[Studies on the pre- and posthepatic plasma histamine concentrations and their possible pathophysiological effects in liver cirrhosis (author's transl)]

Regulation of histamine and diamine oxidase in patients undergoing orthotopic liver transplantation

Increased concentrations of the vasodilator histamine have been observed in patients undergoing abdominal surgery. The role of histamine during orthotopic liver transplantation (OLT) has only been studied in animals. The aim of this study was to measure plasma concentrations of histamine and its degrading enzyme diamine oxidase (DAO) in patients undergoing orthotopic liver transplantation, and assess whether histamine or DAO correlate with intraoperative noradrenaline requirements. Histamine and DAO concentrations were measured in 22 adults undergoing liver transplantation and 22 healthy adults. Furthermore, norepinephrine requirements during liver transplantation were recorded. Baseline concentrations of histamine and DAO were greater in patients, who underwent liver transplantation, than in healthy individuals (Histamine: 6.4 nM, IQR[2.9-11.7] versus 4.3 nM, IQR[3.7-7.1], p = 0.029; DAO: 2.0 ng/mL, IQR[1.5-4.1] versus <0,5 ng/mL, IQR[<0.5-1.1], p < 0.001). During liver transplantation, histamine concentrations decreased to 1.8 nM, IQR[0.5-4.9] in the anhepatic phase (p < 0.0001 versus baseline), and to 1.5 nM, IQR[0.5-2.9] after reperfusion (p < 0.0001 versus baseline). In contrast, DAO concentrations increased to 35.5 ng/ml, IQR[20-50] in the anhepatic phase (p = 0.001 versus baseline) and to 39.5 ng/ml, IQR[23-64] after reperfusion (p = 0.001 versus baseline), correlating inversely with histamine. Norepinephrine requirements during human liver transplantation correlated significantly with DAO concentrations in the anhepatic phase (r = 0.58, p = 0.011) and after reperfusion (r = 0.56; p = 0.022). In patients undergoing orthotopic liver transplantation, histamine concentrations decrease whereas DAO concentrations increase manifold. Diamine oxidase correlates with intraoperative norepinephrine requirements in patients undergoing OLT.

[Investigations on the morphology and biochemistry of wound healing after injury of the liver (author's transl)]

The early phase of wound repair after liver incisions was investigated by histological, enzyme-histochemical, and biochemical methods in guinea pigs. There are considerable differences in cellular and histochemical reactions in comparison to incisions of the skin: 1. The rapid leukocytic reaction showed little change during the observation interval (48 h). In short survival times epithelial cells show signs of hypoxidosis and loss of glycogen at the edge of an incision. Proliferation of organ-specific and mesenchymal cells was observed after more than 24 h. 2. Alterations of the investigated enzymes in the traumatic area are important diagnostic parameters in the early stages of wound healing. 3. In the early 12 h after injury distinct increase of histamine was observed, while serotonin was noticed to decrease. 4. Therefore, the determination of wound age in the early wound reactions after injuries of the liver should include enzymehistochemical methods.

Histamine metabolism in severe obesity before and after jejuno-ileostomy

Histamine metabolism was studied in three patients during histamine-reduced diet before and at intervals after jejuno-ileostomy by analyses of the urinary excretion of non-labelled and 14C-labelled histamine and its metabolites. Labelled histamine was administered intravenously and orally. The preoperative excretion of free histamine and its endogenously formed metabolites was essentially the same as in controls. After intestinal bypass the inactivation of [14C]histamine by both routes of administration was not impaired. Pronounced increases in the excretion of non-labelled conjugated histamine (acetylhistamine) and methylimidazoleacetic acid were found at different intervals postoperatively. This was probably due to histamine synthesis by intestinal bacteria since the diet only contained minute quantities of histamine. It is concluded that the increased urinary excretion of conjugated histamine after intestinal bypass indicated an abnormal bacterial activity in the intestine.