The ACTH/MSH(4-9) analogue ORG 2766 stimulates microtubule formation in axons of central neurons of the snail Lymnaea stagnalis.
Central nervous systems of the pond snail Lymnaea stagnalis were incubated in vitro in different concentrations of ORG 2766 (10(-9)-2.5 x 10(-4) M) for 10 and 20 h. Quantitative ultrastructural study of cross sections of the cerebral commissure showed that the number of microtubules in large axons had increased after 10 h of incubation by approximately 50% (Experiment 1) and 30% (Experiment 2), respectively. No further increase was observed after 20 h of incubation. (The higher concentrations were studied.) Maximal stimulation was already found at a concentration of 10(-8) M. At a concentration of 10(-9) M control levels were observed. It is concluded that ORG 2766 stimulates microtubule formation already at very low concentrations. It is not clear whether the compound stimulates synthesis of tubulin, induces assembly of microtubules, or causes an increase in stability of microtubules. Nevertheless, ultrastructural data on the morphology of the glial cells indicate that these cells are activated by ORG 2766 treatment, which suggest that ORG 2766 has general trophic effects.
Müller
L J
LJ
Faculty of Biology, Vrije Universiteit, Amsterdam, The Netherlands.
Moorer-van Delft
C M
CM
Boer
H H
HH
D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects* / Q000648:ultrastructure; D008195:Lymnaea / Q000187:drug effects* / Q000648:ultrastructure; D008870:Microtubules / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000648:ultrastructure; D010446:Peptide Fragments / Q000494:pharmacology*
D010446:Peptide Fragments; C013765:Org 2766; D000324:Adrenocorticotropic Hormone