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Biomedical subjects

G Curzon

Publications and source records attributed to G Curzon.

At least 199 records · Page 11Linked to original sources

Effects on plasma and brain tryptophan in the rat of drugs and hormones that influence the concentration of unesterified fatty acid in the plasma.

1 The effects on tryptophan distribution and metabolism of drugs altering plasma unesterified fatty acid (UFA) concentration were investigated in the rat.2 UFA and plasma free (i.e. ultrafilterable) tryptophan altered in the same direction.3 Catecholamines and L-DOPA increased both plasma UFA and free tryptophan. L-DOPA also increased brain tryptophan and 5-hydroxyindoleacetic acid (5-HIAA) but decreased brain 5-hydroxytryptamine (5-HT).4 Aminophylline increased plasma UFA and free tryptophan and also brain tryptophan, 5-HT and 5-HIAA. Food deprivation had qualitatively similar effects.5 Insulin decreased plasma UFA and free tryptophan in both fed and food-deprived rats. However, while in fed rats these changes were associated with small decreases of brain indoles, in food-deprived animals small increases occurred.6 Nicotinic acid had only small effects in fed rats but it opposed both the UFA and indole changes in food-deprived animals. Total plasma tryptophan increased in nicotinic acid treated, food-deprived rats.7 There was a tendency towards inverse relations between changes of plasma free and total tryptophan.8 The results suggest that drugs which influence plasma UFA through actions on cyclic AMP thereby alter the binding of tryptophan to plasma protein and that this leads to altered distribution and metabolism of tryptophan.

Aminophylline↗

Amine metabolites in the cerebrospinal fluid of patients with disseminated sclerosis.

Mean homovanillic acid and 5-hydroxyindoleacetic acid concentrations were significantly low in the lumbar CSF of a group of patients with disseminated sclerosis (DS) who were severely disabled but not in the CSF of a less severely restricted group with DS. CSF concentrations were also low in a group of patients with superior cerebellar peduncular tremor due to DS and in a single patient with a similar tremor associated with a post-traumatic brain-stem lesion. The interpretation of abnormal CSF amine metabolite concentrations is discussed in the light of these findings.

Cerebellar Diseases↗