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Biomedical subjects

G Agrup

Publications and source records attributed to G Agrup.

At least 55 records · Page 3Linked to original sources
PubMed1977

Intracellular distribution of dopa and 5-S-cysteinyldopa in Harding-Passey melanoma.

The concentrations of dopa and 5-S-cysteinyldopa were determined in the various cell fractions of Harding-Passey melanomas. Dopa was present in larger amounts than was 5-S-cysteinyldopa in all cell fractions, but the dopa/5-S-cysteinyldopa ratio was lower in the soluble fraction and in the small-granule fraction than in the large-granule fraction. The soluble fraction contained the greatest amount of catechols. These findings are compatible with high tyrosinase activity not only in the melanosomes but also in the small-granule and soluble fractions.

Animals↗
PubMed1977

5-S-cysteinyldopa in the urine of melanoma patients.

A newly discovered amino acid, 5-S-cysteinyldopa, present in the urine of healthy subjects is excreted in pathological amounts in many patients suffering from melanoma metastases. Increased excretion of 5-S-cysteinyldopa may be observed before metastases become clinically evident. Determination of 5-S-cysteinyldopa is superior to determination of dopa+dopamine in the diagnosis of melanoma metastases.

Adult↗
PubMed1977

Glutathionedopa in malignant melanoma.

A human melanoma metastasis was found to contain a substance identical with synthetic glutathionedopa when examined by means of an automatic amino acid analyser, chromatography on a Dowex-50 column, thin-layer electrophoresis, and by fluorimetry. The presence of glutathionedopa in melanoma tissue and of enzymes capable of hydrolysing the glutathione moiety of the molecule, together with the absence of glutathionedopa in the urine, suggest that glutathionedopa is an intermediate substance in the formation of 5-S-cysteinyldopa.

Cysteinyldopa↗
PubMed1976

Demonstration of 3-methoxytyrosine in the urine of melanoma patients.

With the aid of gas chromatography and mass spectrometry a metabolite of dopa, 3-methoxytyrosine, has been demonstrated in the urine of 2 patients with melanoma metastases, the amounts excreted being 4.0 mg and 8.5 mg/24 hours, respectively. 3-Methoxytyrosine could not with certainty be identified in the urines of two normal subjects.

Chromatography, Gas↗
PubMed1975

Formation of cysteinyldopa from glutathionedopa in melanoma.

Glutathionedopa injected intravenously into mice is metabolized and excreted in the urine as a compound with the fluorescence characteristics of cysteinyldopa. Glutathionedopa incubated with a guinea-pig kidney homogenate is metabolized to a compound with the fluorescence characteristics of cysteinyldopa. Boiling of the kidney homogenate prevents the metabolism of glutathionedopa. Incubation of glutathionedopa with a homogenate of a melanoma metastasis led to the formation of a compound with the fluorescence characteristics of cysteinyldopa. Boiling of the melanoma homogenate prevented the metabolism of glutathionedopa. Large amounts of glutathione added to the incubate inhibited the reaction. Lung tissue and blood plasma had no detectable ability to metabolize glutathionedopa. The results show that human melanoma contains one or several enzymes capable of metabolizing glutathionedopa to a smaller dopathioether, probably cysteinyldopa. Such enzymes seem to be normally present in mice and guinea-pigs and have been demonstrated in the guinea-pig kidney.

Animals↗
PubMed1975

Excretion of 5-S-cysteinyldopa in the urine of healthy subjects.

Seventy-six Caucasians, 30 men and 46 women, were investigated for the 24-hour excretion of 5-S-cysteinyl dopa in the urine during the months of September to November, 1973. No subject had had strong sun exposure for at least 4 weeks prior. A preliminary finding of a variation of 5-S-cysteinyldopa with season necessitated this precaution. The excretion varied between 9.0 and 242 mug/24 hours. The mean value in men was 100 mug/24 hours and in women 77.8 mug/24 hours. Subjects with white hair had lower values than those with pigmented hair, but there was no other difference between the excreted amounts in subjects with differing hair colour. There was no variation with age when the subjects with white hair were excluded. No variation with weight or body surface was found. Excretion of dopa and dopamine determined together did not correlate with the excretion of 5-S-cysteinyldopa.

Adolescent↗
PubMed1975

Urinary excretion of 5-S-cysteinyldopa in patients with primary melanoma or melanoma metastasis.

Urinary excretion of 5-S-cysteinyldopa was studied in 9 patients with primary melanoma. All had 5-S-cysteinyldopa excretion in the normal range. In 8 of the patients excretion values decreased after removal of the tumour. Twenty-four patients with clinical signs of melanoma metastasis were examined for 5-S-cysteinyldopa and dopa+dopamine in the urine. 16 of the 24 had pathologically increased excretion of 5-S-cysteinyldopa and 7 of the 24 had pathological excretion of dopa+dopamine. Six of the latter belonged to the group with increased 5-S-cysteinyldopa excretion and one patient had a borderline value of 5-S-cysteinyldopa. Determination of 5-S-cysteinyldopa seems to be of value in the follow-up of patients operated on for primary melanoma.

Adult↗