Metabolically regulated cyclical contractures in microinjectedSpirostomum: A pharmacological study

Summary Spirostomum was treated extracellularly and intracellularly with a range of metabolites to investigate the intracellular regulation of cyclic calcium movements. The results indicate, close links between calcium movements and mitochondrial metabolism.We are grateful to Dr.A. Gaudemar, Institut de Chimie des Substances Naturelle, Gif-sur-Yvette, France for a gift of bongkrekic acid, to Dr.D. C. Aldridge, Biochemistry Dept., I. C. I. Ltd., Macclesfield, U. K. for a gift of avenceolide and toE. M. Ettienne for many hours of discussion. Dr.R. B. Hawkes is a Visiting Research Fellow at the Hebrew University of Jerusalem.