Monoamine oxidase in adult Ascaridia galli

Abstract

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°C. MAO of A. galli appeared to be thermolabile as nearly 80% of its activity was lost when the incubation temperature was increased 5° above optimum.

Characterization of Monoamine Oxidase-A in tropical liver fluke, Fasciola gigantica

“…lumbricoides and N . braziliensis [ 38 , 41 , 42 , 48 , 66 , 67 ] which showed the suppression of MAO activity by the action of varied number of inhibitors.…”

“…MAO also plays a cardinal role in the development of helminths as also seen in case of A . galli [ 38 ]. The levels of MAO and its associated substrate have been found to greatly affect important life functions such as growth promotion [ 39 ], reproduction and egg production [ 40 ].…”

Characterization of mitochondrial monoamine oxidase of Ascaridia galli

“…Enzyme was prepared essentially by the procedure described earlier by MISHRA et al, (1983). MAO activity was determined according to the method of GREEN & HAUGHTON (1961)-with minor modifications (SEN et al, 1968) using tyramine as the substrate which was neutralized before use.…”

Monoamine oxidase in amphistomes and its role in worm motility

“…The oxidative deamination of biogenic monoamines is actively brought about by the enzyme monoamine oxidase, which thereby acts as a major scavenger of monoamines released at the neuronal junctions as well as non-neurotransmitter monoamines present in intestine and other peripheral tissues (Agarwal et al, 1990). The quantitative and qualitative differences in the distribution of biogenic amines which might be involved in the neuromuscular activities, behavioural coordination and metabolic regulation, and also an active MAO, have been observed in a number of helminth species (Mansour, 1962;Nimmo-Smith & Raison, 1968;Bennett & Bueding, 1971;Chou et al, 1972;Hariri, 1974;Moreno & Barrett, 1979;Mishra et al, 1983;Agarwal et al, 1985;Smart, 1988). However, very limited information is available about the role of MAO in the neuromuscular coordination of helminths in general and almost nothing is known in the case of amphistomes.…”