No abstract

The antiphospholipid antibody syndrome is a multisystem disorder characterized by persistently elevated antiphospholipid antibodies and/or arterial or venous thrombosis, thrombocytopenia and recurrent spontaneous abortion. Anticardiolipin antibodies and the lupus anticoagulant are different classes of antiphospholipid antibodies associated with this disorder. Various hematologic, neurologic, obstetric and cutaneous abnormalities are manifest in this syndrome. This article reviews the characteristic features of the antiphospholipid antibody syndrome.

It is generally assumed that C-peptide is not degraded in the liver to any significant extent. This assumption is, however, based on indirect evidence. We therefore measured the hepatic extraction ratio (R) of insulin and C-peptide in anesthetized pigs with simultaneous sampling of portal and hepatic venous blood. Blood samples were taken at one-minute intervals for 10 minutes during basal (unstimulated) experimental conditions as well as after intravenous injection of 1 mg. glucagon into four normal-weight and four obese pigs. The hepatic extraction ratio of insulin or C-peptide was calculated as the portal concentration minus the hepatic concentration divided by the portal concentration. The average pre- and poststimulatory molar ratios of C-peptide to insulin were 1.5 ± 0.11 (S.E.M.) and 1.2 ± 0.06 in portal blood and 3.4 ± 0.21 and 2.2 ± 0.08 in hepatic blood. For all pigs the mean Rc-peptide was 0.30 ± 0.03 and 0.33 ± 0.02 pre- and poststimulatory, respectively. The corresponding figures for Rinsulin (0.71 ± 0.02 and 0.61 ± 0.02) were both significantly higher (p < 0.01). The mean R-values for C-peptide and insulin were consistently higher in obese pigs than in normal-weight pigs (p < 0.01). Additional experiments in two normal-weight pigs showed that ligation of the hepatic artery elicited a significant fall of mean Rc-peptide, which, however, never became less than 0.12. These results suggest that besides the wellknown hepatic extraction of insulin, the livers of anesthetized pigs also extract significant amounts of endogenous C-peptide. Hepatic extraction of C-peptide is, however, about 50 per cent lower than that of insulin.