[Guanyl cyclase activities in clonal lines of cultured astroblasts and neuroblasts]

Guanylate cyclase was found to be present in a number of astroblast and neuroblast clones. No correlations were observed between the enzyme activity and the nature of the clone. The enzyme shows a requirement for manganese ions and is stimulated by calcium. When the astroblast clone NN is cultured together with the neuroblast clone M1 for two months and the astroblast cells again isolated, a reduced guanylate cyclase activity was found.