Biochemistry and genetics of monoamine oxidase.

Immune expulsion of parasitic nematodes from the alimentary tract.

The functional role of monoamine oxidases A and B in the mammalian central nervous system

Publisher Summary This chapter discusses the diethylcarbamatine and new compounds for the treatment of filariasis. Diethylcarbamazine is 1-diethylcarbamyl-4-methylpiperazine; it is also known as Hetrazan, Banocide, Notezine, Caricide, Carbilazine, Supatonin, and R.P. 3799. It was first put out as the chloride, but is now issued as the dihydrogen citrate, which contains only half its weight as base. In reports, it should be indicated whether the doses refer to a specific salt or to the base; unless otherwise stated, it can usually be assumed that the dose refers to the citrate. Diethylcarbamazine is a white powder, freely soluble in water, and has a slightly unpleasant sweetish taste. It is stable under all ordinary laboratory conditions. Furthermore, it is fully stable to autoclaving, even if mixed with diet (simulating cooking procedure). When diethylcarbamazine is given by mouth to either animals or man, it is rapidly absorbed from the alimentary canal. One dose of 10 mg base/kg produces a peak blood level of 4–5 μg/ml in 3 hours (when toxic symptoms are most prominent); the level gradually falls to zero within about 48 hours. Most of the excretion in the urine occurs in the first 24 hours during which time 10–26% of the dose may be recovered as diethylcarbamazine.

Diethylcarbamazine and new compounds for the treatment of filariasis.

The pharyngeal component of the enteric nervous system of the parasitic nematode, Ascaris suum exhibits immunoreactivity for serotonin (5-hydroxytryptamine or 5-HT) and for FMRFamide-like peptides. This paper describes the application of an in vitro pharmacological approach to investigate the functional role of 5-HT and FMRFamide-like peptides. The pharyngeal pumping behaviour of Ascaris suum was monitored using a modified pressure transducer system which measures pharyngeal pressure changes and therefore pumping. The pharynx did not contract spontaneously; however, 5-HT (10-1000 microM) stimulated pumping at a frequency of 0.5 Hz. FMRFamide had no apparent effect on pharyngeal pumping. The native nematode FMRFamide-related peptide (FaRP), KSAYMRFamide inhibited the pumping elicited by 5-HT. The duration of inhibition was dose-dependent (0.1-1000 nM) with a threshold of 0.1 nM. In 4 preparations, the inhibition of the pharyngeal muscle was preceded by an initial excitation and increase in the amplitude of pharyngeal pressure changes. The pharynx is involved in various nematode processes, including feeding, regulation of hydrostatic pressure and excretion. The role of 5-HT and KSAYMRFamide in the pharyngeal function of nematodes is discussed.

The action of serotonin and the nematode neuropeptide KSAYMRFamide on the pharyngeal muscle of the parasitic nematode, Ascaris suum

Ascaris lumbricoides and Ascaridia galli: biogenic amines in adults and developmental stages.

Litomosoides carinii: biogenic amines in microfilariae and adults.

Monoamine oxidase (MAO), catalysing oxidative deamination of biogenic monoamines, has been detected in adult Ascaridia galli. MAO was present in mitochondria and deaminated noradrenaline at the maximal rate, although serotonin, adrenaline, tyramine and dopamine were also degraded but more slowly. Of the organs studied, the body wall, female reproductive organ and intestine, the body wall (containing neuronal structures) showed highest MAO activity. Km value for chick ascarid mitochondrial MAO using tyramine as substrate was 1.66 X 10(-3) M and it was most active at 2.5 mM tyramine concentration, pH 7.5 and 40 degrees C. MAO of A. galli appeared to be thermolabile as nearly 80% of its activity was lost when the incubation temperature was increased 5 degrees above optimum.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022149X00011007

Monoamine oxidase in adult Ascaridia galli

Oxidative deamination of various biogenic monoamines by Ascaridia galli monoamine oxidase (MAO) was blocked by different mammalian MAO inhibitors, namely, iproniazid, trans-PcP, nialamide and pargyline and the blockade was observed to be time as well as concentration dependent. The binding of inhibitors with chick ascarid MAO was of the irreversible type and the nature of the inhibition was competitive. Pargyline showed lowest I50 (8 microM) and Ki (12 microM) values. Chlorgyline and deprenyl at 100 microM concentration inhibited MAO by about 60 and 40% respectively, indicating the presence of both type A and type B MAO in A. galli.

Ramanuj Sen

Papers

Ascaris lumbricoides and Ascaridia galli: biogenic amines in adults and developmental stages.

Litomosoides carinii: biogenic amines in microfilariae and adults.

Monoamine oxidase in adult Ascaridia galli

Characterization of mitochondrial monoamine oxidase of Ascaridia galli.