Serum histidine-rich glycoprotein during pregnancy and hormone treatment.

The concentration of serum histidine-rich glycoprotein (HRG) was determined by radial immunodiffusion during weeks 27-42 of pregnancy in 110 pregnant women. HRG was also measured in serum from 11 lactating women 6 weeks post partum, from 11 women taking oral contraceptives, and from four women having progestin-releasing subcutaneous capsules used for contraception. The concentration of serum HRG decreased during the last trimester of pregnancy reaching a nadir at the 36-37th week (HRG 49 +/- 14 g/l, mean +/- SD).

The binding of porphyrins by ligandin.

Spectrophotometric and equilibrium-dialysis measurements show that ligandin (glutathione S-transferase B, EC 2.5.1.

Isolation and partial characterization of rat liver porphyrin binding proteins.

14C-coproporphyrin III was added to hemoglobin-free cytoplasmic rat liver extract. Molecular sieving was performed on Sephadex G-75 column. The protein content of each fraction was measured at 280 nm in double beam spectrophotometer and the radioactivity by means of liquid scintillation counter.

Multicompartment analysis of 14C-labelled coproporphyrin and uroporphyrin kinetics in human beings.

14C-labelled coproporphyrin I and III and uroporphyrin I were injected intravenously into healthy human subjects. Two experiments were performed with each porphyrin. Counting of blood, urine and faeces was made as a function of time.

Hereditary hepatic porphyrias in Finland.

The occurrence of hepatic porphyrias--acute intermittent porphyria (AIP) and variegate porphyria (VP)--in Finland has been studied. During a period of 9 years 107 patients with AIP and 45 patients with VP were found. The prevalence of hereditary hepatic porphyrias was calculated to be 3.

Interaction of rabbit hemoplexin with copro- and uroporphyrins.

Rabbit hemopexin forms equimolar complexes in vitro with the I and III isomers of both coproporphyrin and uroporphyrin. The apparent dissociation constants (Kd) of these complexes are estimated to be 4-10(-7) M for coproporphyrin-hemopexin and 10(-6) M for uroporphyrin-hemopexin by equilibrium dialysis and quenching of protein fluorescence. Results of competitive binding experiments suggest that all four porphyrins bind at the heme-binding site of hemopexin, and that the relative affinity of rabbit hemopexin for these porphyrins is: deuteroheme greater than coproporphyrin I or III greater than uroporphyrin I or III.