Properties and function of the mitochondrial monoamine oxidase in eggs and early embryo

Several lines of investigations demonstrate that neurotransmitter monoamines like serotonin and catecholamines may influence some developmental processes even before the nervous system formation in various animal groups. One of the aspects of interest in this context is whether the modulation of the levels of these biogenic amines in early embryos involves a MAO activity. In this review we have summarized literature data on the characteristics and functional significance of MAO activity in eggs and in early embryos of several animal species. A considerable level of MAO activity has been found in eggs of sea urchins, teleosts and amphibians and some properties of this activity have been described. Moreover. changes in enzyme activity hare been observed during early embryogenesis of these groups and also of birds. These findings; together with other observations on the effects of anti-MAO agents on early embryos indicate that, at least in some species, MAO activity might be of critical importance in regulating monoamine In els starting from the early stages of development.