scholarly journals Pharmacological Modulation of Behaviour, Serotonin and Dopamine Levels in Daphnia magna Exposed to the Monoamine Oxidase Inhibitor Deprenyl

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 187
Author(s):  
Marina Bellot ◽  
Melissa Faria ◽  
Cristian Gómez-Canela ◽  
Demetrio Raldúa ◽  
Carlos Barata

This study assessed the effects of the monoamine oxidase (MAO) inhibitor deprenyl in Daphnia magna locomotor activity. The mechanisms of action of deprenyl were also determined by studying the relationship between behaviour, MAO activity and neurotransmitter levels. Modulation of the D. magna monoamine system was accomplished by 24 h exposure to two model psychotropic pharmaceuticals with antagonistic and agonistic serotonin signalling properties: 10 mg/L of 4-chloro-DL-phenylalanine (PCPA) and 1 mg/L of deprenyl, respectively. Contrasting behavioural outcomes were observed for deprenyl and PCPA reflected in decreased basal locomotor activity and enhanced habituation for the former compound and delayed habituation for the latter one. Deprenyl exposure inhibited monoamine oxidase (MAO) activity and increased the concentrations of serotonin, dopamine and the dopamine metabolite 3-methoxytyramine in whole D. magna extracts. Our findings indicate that D. magna is a sensitive and useful nonvertebrate model for assessing the effects of short-term exposure to chemicals that alter monoamine signalling changes.

1975 ◽  
Vol 67 (3) ◽  
pp. 371-383 ◽  
Author(s):  
J. P. MALTIER ◽  
F. CAVAILLE

SUMMARY Injection of a monoamine oxidase (MAO) inhibitor (nialamide) into the uterus of an anaesthetized and laparotomized rat on day 20 of pregnancy severely disturbed parturition. Injection of the solvent (0·9% isotonic NaCl solution) at the same stage of gestation produced the same but less frequent disturbances. When the rats were injected on days 19 or 21, impairment was less marked than on day 20. Therefore, day 20 seems to be a critical period for the onset of parturition. Injection of Ringer solution into the uterus on day 20 had effects analogous to those of saline injection at the same stage. Anaesthesia induced with ether, laparotomy of the pregnant rat on day 20, and handling of the uterine horns without injection of either Ringer or NaCl also disturbed parturition in 70% of the rats treated. Nevertheless, disorders were not as severe as those after injection. Laparotomy alone on day 20 did not disturb parturition. The effects on parturition of a saline injection into the uterus on day 20 were greatly decreased when the injection was performed on pregnant rats adrenalectomized on day 14, or on pregnant rats pretreated on days 18 and 19 with an agent blocking the adrenergic β receptors (propranolol); 70–80% of the treated rats had normal deliveries. In control rats, uterine catecholamine levels were markedly modified between days 21 and 22 of gestation. These changes did not occur in rats injected with MAO inhibitor or saline.


1969 ◽  
Vol 43 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Z. KOREN ◽  
Y. PFEIFER ◽  
F. G. SULMAN

SUMMARY Intra-aortic injection of [3-14C]5-hydroxytryptamine creatinine sulphate ([14C]5-HT) into oestrogen or oestrogen-progestogen treated rats showed a pattern of homogeneous uptake similar to that found in untreated normal rats. In pregnant rats the injection resulted in a preferential uptake by the myometrium. Injection of a MAO inhibitor (pargyline hydrochloride, Eutonyl) into the amniotic sac, preceding the [14C]5-HT injection by 30 min., changed this pattern to a preferential accumulation in the myometrium and the spleen, perhaps due to unhampered transport of preserved 5-HT by the thrombocytes to the spleen. When [14C]5-HT was injected i.p. into the foetuses they retained high amounts of exogenous 5-HT. Myometrium and placenta also showed increased 5-HT uptake. This finding—taken together with the established fact that foetal 5-HT increases and placental monoamine oxidase decreases steadily up to term—suggests that at term the release of foetal 5-HT may enrich the maternal myometrium with 5-HT through the umbilical arteries without its entering the general blood circulation. It is also possible that additional maternal 5-HT may accumulate in the myometrium sensitized by the oestrogen surge at term. The importance of these mechanisms for the induction of labour is discussed.


2008 ◽  
Vol 11 (2) ◽  
pp. 14 ◽  
Author(s):  
Kathryn G. Todd ◽  
Glen B. Baker

PURPOSE. To compare phenelzine (PLZ), an antidepressant drug with anxiolytic properties which inhibits monoamine oxidase (MAO) but also elevates rat brain levels of the amino acids ?-aminobutyric acid (GABA) and alanine (ALA), with vigabatrin (VIG), an anticonvulsant which elevates brain GABA by inhibition of GABA transaminase (GABA-T), with regard to their actions on brain levels of GABA and ALA and on activities of MAO, GABA-T and ALA transaminase (ALA-T). METHODS. Male rats were administered PLZ (10 mg/kg) or VIG (1,000 mg/kg) i.p., and the rats were euthanized 4 hours later and the brains removed for analysis of levels of GABA and ALA (by electron capture gas chromatography after derivatization) and activities of MAO, GABA-T and ALA-T (radiochemical assays). RESULTS. Both PLZ and VIG inhibited GABA-T and elevated GABA levels. Only PLZ inhibited MAO and ALA-T and elevated ALA levels. The effects of PLZ on both amino acids and their transaminases were blocked by pre-treatment with the MAO inhibitor tranylcypromine. This pretreament had no effect on the inhibition of GABA-T or the elevation of brain GABA levels produced by VIG. CONCLUSIONS. At the doses studied, PLZ was as effective as VIG at elevating brain GABA levels, but, unlike VIG, also inhibited MAO and ALA-T (and increased brain ALA levels). Pretreatment of rats with the MAO inhibitor tranylcypromine prevented the increase in brain GABA and ALA levels with PLZ, but did not block the effect of VIG on GABA. These observations with tranylcypromine and PLZ support the hypothesis that an active metabolite of PLZ produced by the actions of MAO on this drug plays a major role in its GABA- and ALA-elevating actions.


1990 ◽  
Vol 7 (2) ◽  
pp. 159-167
Author(s):  
Sinead O'Brien ◽  
Patrick McKeon

AbstractInterest in the monoamine oxidase (MAO) inhibitors has been revived over the past fifteen years since the publication of studies and reviews which argue their relative safety and efficacy in certain patient subgroups. The authors conclude that there is a continuing role for the MAO inhibitors in treating atypical depressive illness and panic disorders. Careful selection of patients to be commenced on MAO inhibitor treatment is advised. When prescribed alone or in combination with lithium there is evidence to support a usefulness for MAO inhibitors in depression resistant to the tricyclic antidepressants. Their efficacy in the depressed phase of bipolar affective disorder or in combination with the tricyclic antidepressants remains unproven. The risk of anaesthesia while a patient is receiving MAO inhibitor treatment may be less than heretofore believed. There is realistic hope of finding among the short-acting selective MAO inhibitors an effective antidepressant which is also free from tyramine related effects. With the increasing difficulties of evaluating new drugs on account of ethical and governmental constraints, it may however be some time before the preliminary hopeful findings can be substantiated in larger groups of patients.


1989 ◽  
Vol 4 (3) ◽  
pp. 175-181
Author(s):  
J.F. Lipinski ◽  
R.C. Alexander

SummaryThe authors have reviewed 13 published studies on methionine administration, usually in combination with a monoamine oxidase inhibitor (MAOI), to chronically psychotic patients, using modern (DSM-III) diagnostic criteria. Four of these studies contained sufficient descriptive data to allow reappraisal of the effects. The results of the review suggest that a proportion of the patients experienced the induction of a manic episode/antidepressant effects rather than the reported worsening of schizophrenia while treated with a methionine-MAOI combination. It is suggested that these observations are consistent with recent findings that S-adenosyl-L-methionine (SAMe) has antidepressant and mania-inducing effects.


1995 ◽  
Vol 22 (s1) ◽  
pp. S86-S87 ◽  
Author(s):  
N. Hamaue ◽  
T. Endo ◽  
M. Hirafuji ◽  
N. Yamazaki ◽  
H. Togashi ◽  
...  

2010 ◽  
Vol 3 (4) ◽  
pp. 213-215
Author(s):  
Junji Takeshita ◽  
Deborah Goebert ◽  
John Huh ◽  
Brett Lu ◽  
Diane Thompson ◽  
...  

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