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Biomedical subjects

J R Smythies

Publications and source records attributed to J R Smythies.

At least 19 recordsLinked to original sources
PubMed1979

On the molecular structure of some prostaglandin receptors.

Hypotheses are presented of the detailed molecular structure of two prostaglandin receptors both concerned in tumor-promotion processes. These structures have been derived by the comparison of the molecular structure of agents active at the site with (i) a simple theoretical protein structure and (ii) the known x-ray structure of phospholipase A2. The first model receptor is stimulatory to the tumor-promotion process and may be located on the control system for ornithine decarboxylase. The binding of PG here is cooperative with the binding of Ca++. Naturally-occurring agonists at this receptor may include members of the cathartic class of drugs such as colocynth, chrysarobin, etc. Naturally-occurring antagonists at this site may include a number of anti-tumor compounds such as datiscoside. The second model receptor (PGE1) is inhibitory to the tumor-promotion process and is located at a specific allosteric site on the x-ray-determined structure of phospholipase A2. This site overlaps for one for lysolecithin (excitatory), for which tumor-promoting phorbol esters such as TPA are agonists and some anti-tumor drugs such as maytansine may be antagonists.

Antineoplastic Agents↗
PubMed1979

Biochemistry and the schizophrenias.

This paper reviews the present status of the transmethylation and the dopamine hypotheses of schizophrenia and presents recent data on the definitive identification and measurement of the endogenous hallucinogen, dimethyltryptamine (DMT) in human cerebrospinal fluid and urine. Elevated levels are found in some cases of schizophrenia and of liver disease. Evidence is discussed showing that DMT may be a normal neuroregulatory agent which is responsive to stress or emotional reactions.

Dopamine↗
PubMed1978

Hallucinogenic N-methylated indolealkylamines in the cerebrospinal fluid of psychiatric and control populations.

The incidence and quantities of dimethyltryptamine and O-methylbufotenine were studied in the cerebrospinal fluid of patients suffering acute schizophrenic illnesses and in surgical and neurological control groups. Some schizophrenic patients have higher levels of both amines than do controls, though the differences in distribution did not reach statistical significance in the sample studied. The gas-chromatographic technique used is sensitive at the low picogram level.

Affective Symptoms↗