Bernard Ecanow

Autoxidation of linoleic acid

contraction of 3 cm. The muscle responded within 10 to 15 sec of adding the 5-HT to the bath and reached maximum contraction in 45 sec; relaxation to the baseline occurred 1 min after 5-HT was washed out ; another dose of ~ H T could be added after 2 min. The preparation attained maximum sensitivity after 10 to 12 additions of ~ H T and its response remained consistent for at least 3 hr. Methysergide (Sandoz) in a concentration of g/ml completely abolished the response to g/ml of 5-HT. Doses and concentrations are in terms of base. A tracing showing graded response by the rat stomach strip preparation with the above modifications to various doses of ~ H T is shown in Fig. 1. We have not been able to determine precisely the cause for this improvement. However, we would like to share this experience with others who may wish to make use of this preparation for the rapid assay of 5-HT. Department of Pharmacology, University of Singapore, Singapore 3, Malaysia. May 28, 1965