[Study of bioavailability of different forms of synthetic beta-carotene in volunteers].

The concentration of beta-carotene analyzed in blood serum of 30 healthy men and women aged 17-50 years by the method of HPLC in May-June 1990 was in range 3.3-29.5 and in average 12.

[Reconstruction of muscle glycogen phosphorylase b from an apoenzyme and pyridoxal-5'-phosphate and its analogs. Interaction of apophosphorylase and the reconstructed enzyme with specific ligands].

Sedimentation methods were used to study the effects of modification of the pyridoxal-5'-phosphate (PLP) molecule at the 5th position on the affinity of reconstituted muscle glycogen phosphorylase b for the substrate (glycogen) and the allosteric inhibitor (FMN) as well as on the enzyme capacity to association induced by AMP. Reconstituted phosphorylase b was obtained with PLP analogs containing at the 5th position -CH2-CH2-COOH (analog I), trans-CH=CH-COOH (analog II) or -C identical to COOH (analog III) residues. Reconstitution of phosphorylase b is accompanied by the recovery of the enzyme quaternary structure.

[Bioavailability and pharmacodynamics of various forms of synthetic beta-carotene in volunteers].

The biological availability of artificial beta-carotene as a water-soluble versus oily formulation based on cyclodextrin (Cyclocar tablets) was studied on volunteers given a single dose of 25 mg. The concentrations of beta-carotene and major carotenoids were measured in the blood serum during the experiment by high performance liquid chromatography. The maximum content of beta-carotene in the serum was attained 24-30 and 30-48 hrs after oily formulations and Cyclocar and were 48.

[The cytochrome P-450-dependent mono-oxygenase system of the liver and interleukin-1 production by the macrophages in adjuvant arthritis in rats under the influence of beta-carotene].

A relationship between the production of interleukin 1 (IL-1) by macrophages from adjuvant-induced arthritic rats and cytochrome P-450-dependent hepatic microsomal monooxygenase was studied. The synthesis of IL-1 by splenic and peritoneal macrophages on day 17 postadjuvant treatment was not altered, but the hepatic cytochrome P-450 levels and monooxygenase activity were significantly decreased. Beta-carotene treatment of arthritic rats reduced hind paw swelling and concurrently stimulated the ability of macrophages to secrete IL-1 and increased the cytochrome P-450 levels and the activity of hepatic monooxygenase.