Effects of intestinal insulin-like peptide on glucose catabolism in male adult Locusta migratoria

An insulin‐like peptide (ILP) extracted from midgut of 25‐day‐old male adult Locusta migratoria can modify the relative activity of the two main pathways of glucose catabolism. The effect of ILP on the activity of the pentose cycle and the glycolytic‐citric acid cycle in Locusta migratoria was evaluated by a radiorespirometric method by means of [1‐14C] glucose and [6‐14C]glucose as substrates. The time course of the ILP effect was determined. The insulin‐like peptide increases the relative activity of the pentose cycle. This effect is rapid and of short duration. Injected mammalian insulin has a similar effect.