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Biomedical subjects

G Cohen

Publications and source records attributed to G Cohen.

At least 469 records · Page 26Linked to original sources
PubMed1972

6,7-Dihydroxytetrahydroisoquinoline: uptake and storage by peripheral sympathetic nerve of the rat.

6,7-Dihydroxy-1,2,3,4-tetrahydroisoquinoline is a pharmacologically active alkaloid that can be formed by condensation of dopamine with formaldehyde. We used fluorescence microscopy to study in vitro the uptake and storage of this compound by sympathetic nerves of the rat iris. Rats were treated with reserpine or with the methyl ester of alpha-methyl-p-tyrosine in order to deplete the endogenous catecholamine stores. Accumulation of the alkaloid was about onetenth that of norepinephrine. Uptake was completely blocked by 10-(5)M desmethylimipramine. These results offer some explanation for the sympathomimetric properties of the alkaloid. Similar results can be expected for similar tetrahydroisoquinolines that may be formed in vivo from endogenous catecholamines during ingestion of alcoholic beverages.

Animals↗
PubMed1971

Emergency aorto-coronary venous bypass graft in cardiogenic shock.

The mortality rate of shock complicating myocardial infarction is extremely high (80-100%) despite intensive medical management. Five patients with acute myocardial infarction and cardiogenic shock received an emergency aorto-coronary bypass graft, from three hours to five days after the onset of infarction and three to nine hours after the onset of shock. Selective coronary angiography was performed in all cases prior to operation. Four of the five patients survived and were discharged from hospital. Two cases with A-V dissociation and complete heart block reverted to normal sinus rhythm after the operation. This limited experience indicates that emergency aortocoronary bypass graft surgery can reduce mortality significantly in properly selected cases of cardiogenic shock.

Aged↗
PubMed1971

Inhibition of biogenic amine uptake by hydrogen peroxide: a mechanism for toxic effects of 6-hydroxydopamine.

Hydrogen peroxide, dialuric acid, or 6-hydroxydopamine inhibited the uptake of dopamine, norepinephrine, and serotonin into rat brain synaptosomal preparations. The addition of catalase protected all systems, but catalase was only partially protective for 6-hydroxydopamine acting upon catecholamine uptake. The data show that 6-hydroxydopamine generates hydrogen peroxide and that hydrogen peroxide can damage the biogenic amine uptake systems. Part of the damage caused by the 6-hydroxydopamine that accumulates in the catecholamine nerve terminals in vivo may be attributed to the hydrogen peroxide.

Amines↗