Abstract
Both noradrenaline and dopamine inhibit growth and maturation of oocytes in sea urchins. The in vitro action of these drugs on gonads was accompanied by a decrease in intensity of incorporation of labelled RNA and protein precursors into oocytes in their cytoplasmic growth. The monoaminergic system appears to participate in the regulation of oogenesis in sea urchins besides the peptidergic neurosecretory system.