OBJECTIVE Lesch-Nyhan disease (LND) is caused by congenital deficiency of the purine recycling enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt). Affected patients have a peculiar neurobehavioral syndrome linked with reductions of dopamine in the basal ganglia. The purpose of the current studies was to determine the anatomical basis for the reduced dopamine in human brain specimens...

Two stable mouse cell mutants Ao and RAG, which are resistant to 8-azaguanine and deficient in hypoxanthine-guanine phosphoribosyl transferase (HGPRT), have been studied in order to establish the nature of molecular changes conferring the mutant phenotypes. A specific precipitating rabbit antiserum was prepared against the normal HGPRT purified from mouse tissues, and used to test for cross-rea...

Northern elephant seals are naturally adapted to prolonged periods (1-2 months) of absolute food and water deprivation (fasting). In terrestrial mammals, food deprivation stimulates ATP degradation and decreases ATP synthesis, resulting in the accumulation of purines (ATP degradation byproducts). Hypoxanthine-guanine phosphoribosyl transferase (HGPRT) salvages ATP by recycling the purine degrad...

The human lymphoblast line MGL8 was treated with HAT and subsequently "mutagenized" with EMS (200 microgram/ml) to give 15% survival, and 6-thioguanine-resistant cells were selected by cloning in soft agarose containing the drug (1 microgram/ml). Eighteen sublines of independently derived resistant clones were isolated and studied in detail. One subline had a low residual HGPRT activity of abou...

2'-Deoxycytidine (dCyd), a pyrimidine nucleoside found at high concentrations in the plasma of cancer patients with a poor prognosis after chemotherapy, is considered to be a biomarker for breast cancer. 5-Fluorouracil (5FU) is a nucleoside analog and is used as an anti-tumor agent in patients whose plasma dCyd concentrations are increased. Because both dCyd and 5FU are pyrimidine analogues, it...

Delayed growth arrest was observed in HL-60 acute promyelocytic leukemia cells after exposure to 6-thioguanine (TG). This growth arrest occurred in both wild-type HL-60 cells exposed to 2 microM TG and an HL-60 clone lacking hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity at a 500-fold higher concentration of drug. Both cell lines continued replication during an initial 4-day pe...

1. Hypoxanthine--guanine phosphoribosyltransferase (HGPRT) activity was measured in erythrocyte haemolysates and quadriceps muscle extracts of normal and dystrophic 129 ReJ and C57 BL/6J mice with [8(-14)C]hypoxanthine as substrate and 5-phosphorylribose 1-pyrophosphate as a ribose 5-phosphate donor. [8(-14)C]Inosine monophosphate formed was separated by high-voltage electrophoresis and radioac...

SIX INTERSPECIFIC SOMATIC HYBRID CELL LINES WERE DERIVED FROM A MOUSE LINE DEFICIENT IN HYPOXANTHINE: guanine phosphoribosyltransferase (HGPRT) and human diploid cells with normal enzyme activity. Human HGPRT was present in all six hybrids and the clones derived from them. However, in two of the six, and in some clones from another two, human glucose-6-phosphate dehydrogenase (G6PD) was absent....