Presence of prostaglandins (PGs) in Tetrahymena pyriformis, GL and the effect of aspirin.

: Tetrahymena pyriformis GL appears to require prostaglandins, either B, E or F series for growth, as demonstrated by the deleterious effect of aspirin. The latter inhibits prostaglandin synthetase (cyclooxygenase). Aspirin inhibited 50% growth of a 24 hr culture of T. pyriformis at a dose of approximately 200 micrograms/ml and completely inhibited at 600 micrograms/ml. Extraction with acid ethyl acetate: isopropanol solvent of 2.8 x 10(8) cells yielded 41.3 mg of lipid of which 62.8% and 34.5% were PGE2 and PGB, respectively. It is suggested that PGs are important for the growth of T. pyriformis and that the organism may be a useful source of natural PGs. Additionally, T. pyriformis may be useful in studies of the PGs pathway.