Porphyria-induced hepatic porphyrinogen carboxy-lyase inhibitor and its interaction with the active site(s) of the enzyme.

Porphyrinogen carboxy-lyase is an enzyme that sequentially decarboxylates uroporphyrinogen III (8-COOH) to yield coproporphyrinogen III (4-COOH). In mammals this enzyme activity is impaired by hexachlorobenzene treatment, through generation of an enzyme inhibitor. The interaction of porphyrinogen carboxy-lyase inhibitor, extracted from the liver of hexachlorobenzene-treated rats, with substrate decarboxylation sites on the enzyme, was studied using four different carboxylated substrates belonging to the isomeric III series of naturally-formed porphyrinogens containing 8-,7-,6- and 5-COOH.

A general strategy for isolation of endothelial cells from murine tissues. Characterization of two endothelial cell lines from the murine lung and subcutaneous sponge implants.

A rapid, reproducible method for the isolation of murine endothelial cells (ECs) has been developed. Murine ECs were highly enriched by collagenase digestion of mechanically minced lung and subcutaneous sponge implants followed by specific selection with rat anti-mouse CD31 (i.e.

Anti-tumor activity of cytokines against opportunistic vascular tumors in mice.

Polyoma middle T (PmT)-transformed endothelial cells may represent a unique murine model for human opportunistic vascular tumors. The present study was designed to evaluate the anti-tumor potential of a panel of 13 cytokines against murine PmT-transformed endothelial cells. Interferon gamma (IFNgamma) and transforming growth factor beta 1 (TGFbeta1) substantially decreased in a dose-dependent manner the proliferation of a panel of 6 PmT-transformed cell lines.

Erythrocyte uroporphyrinogen I synthase in rats treated with the hepatic carcinogen diethylnitrosamine.

Uroporphyrinogen I Synthase (URO-S) activity was measured in erythrocytes of female and male rats which had received diethylnitrosamine (DENA) as an inducer of hepatic tumors. Twenty-two weeks after the last dose of the carcinogen, the rats showed statistically significant increases in the URO-S activity. Differences in the body weight, erythrocyte porphyrin content or the hematocrit between treated and control rats were not found.

Porphyrins and porphyrinogen carboxy-lase in hexachlorobenzene-induced porphyria.

1. Qualitative and quantitative studies of the porphyrins and the porphyrinogen carboxylyase of the liver, spleen, kidney, harderian gland and erythrocytes from normal rats and from those hexachlorobenzene-induced porphyria were carried out. 2.