ABSTRACT
The influence of parasitism on host biogenic amine levels was investigated in Nippostrongylus brasiliensis infected rats. Amine levels were estimated in tissues surrounding Nematods in their biological environment: the lung and intestinal mucus. D0 being the day of infestation, tissues were obtained at 24, 30 and 45 hrs, and every day between D4 and D14 (when the rat was completely deparasited by the self-cure phenomenon). Biogenic amines belonging to the serotoninergic pathway were quantified by HPLC with electrochemical detection. In the lungs and mucus, parasitism resulted in an important decrease in serotonine (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as opposed to the immediate 5-HT precursor, the 5-hydroxy-tryptophane (5-HTP). Host response to parasitism is translated by serotoninergic pathway levels. This leads to two hypotheses: 5-HT turn-over may be accelerated, but the inhibition of 5-HT synthetic enzyme, 5-hydroxytryptophane hydroxylase, by the parasite present in the host seems more probable.
Subject(s)
Intestinal Mucosa/metabolism , Lung/metabolism , Nippostrongylus , Serotonin/metabolism , Strongylida Infections/metabolism , Animals , Hydroxyindoleacetic Acid/metabolism , Male , Rats , Rats, WistarABSTRACT
Norepinephrine, 5-hydroxytryptophan, octopamine, dihydroxyphenylacetic acid, N-acetyldopamine, dopamine, 5-hydroxyindoleacetic acid, N-acetylserotonin, tyramine, tryptophan and serotonin in larvae (third free stage and parasitic stages) and adult males and females (at defined ages during the intestinal phase) of the parasitic nematode Nippostrongylus brasiliensis were quantified simultaneously by high-performance liquid chromatography with electrochemical detection. Biogenic amine levels depended on the stage, the age and the sex of parasites and on environmental conditions. Their physiological roles in reproductively competent adults of this nematode are discussed in relation to exuviation and egg laying. Parallel fluctuations in free ecdysteroids and norepinephrine were observed in females from the same worm populations.
Subject(s)
Biogenic Monoamines/metabolism , Nippostrongylus/metabolism , 3,4-Dihydroxyphenylacetic Acid/metabolism , 5-Hydroxytryptophan/metabolism , Animals , Dopamine/analogs & derivatives , Dopamine/metabolism , Ecdysteroids , Female , Hydroxyindoleacetic Acid/metabolism , Insect Hormones/metabolism , Larva/metabolism , Male , Nippostrongylus/growth & development , Nippostrongylus/pathogenicity , Norepinephrine/metabolism , Octopamine/metabolism , Rats , Rats, Wistar , Serotonin/analogs & derivatives , Serotonin/metabolism , Sex Characteristics , Steroids/metabolism , Tryptophan/metabolism , Tyramine/metabolismABSTRACT
Although fish venoms exert a cardiovascular effect, the presence of adrenergic substances was not previously demonstrated. Chromatographic analysis with electrochemical detection showed the presence of substances co-migrating with norepinephrine, dopamine and tryptophan. Serotonin, which was thought to be implicated in the intense pain following fish envenomation, was not detected. Norepinephrine was identified as a component of the stonefish Synanceia verrucosa venom by gas chromatography-mass spectrometry.
