Sloley BD. gamma-Glutamyl conjugation of 5-hydroxytryptamine (serotonin) in the earthworm (Lumbricus terrestris).
Neurochem Res 1994;
19:217-22. [PMID:
7910382 DOI:
10.1007/bf00966819]
[Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The conversion of 5-hydroxytryptamine to several potential metabolites was examined in the annelid earthworm (Lumbricus terrestris). 5-hydroxytryptamine and some related amines were found to be present in several tissues of the earthworm. Injection of 5-hydroxytryptamine into the body cavity of the earthworm resulted in the production of a gamma-glutamyl conjugate of 5-hydroxytryptamine. Incubations of the anterior nerve cord of the earthworm resulted in the accumulation of considerable amounts of 5-hydroxytryptamine and gamma-glutamyl 5-hydroxytryptamine in the incubation medium. The earthworm did not produce any N-acetyl 5-hydroxytryptamine and only very little 5-hydroxyindoleacetic acid. Experiments involving the injection of radiolabeled 5-hydroxytryptamine or coinjection of radiolabeled glutamic acid with unlabeled 5-hydroxytryptamine into the earthworm resulted in the production of radiolabeled gamma-glutamyl 5-hydroxytryptamine. This work demonstrates that the enzymatic conversion of 5-HT in the earthworm is markedly different from that of vertebrates and insects.
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