Induction of hypoglycaemia and accumulation of 5‐hydroxytryptamine in the liver after the injection of mitogenic substances into mice

Abstract

Various mitogenic substances (concanavalin A, pokeweed mitogen, polyl: polyC and a phorbol diester), as well as lipopolysaccharides (LPS or endotoxins), produced hypoglycaemia after being injected into mice. However, non‐mitogenic immuno‐stimulants (zymosan, carrageenan, an adjuvant peptide and interferon) did not induce hypoglycaemia. All of the mitogenic substances also induced an increase in 5‐hydroxytryptamine (5‐HT) in liver, but the non‐mitogenic substances did not have this effect. The time course of the development of hypoglycaemia was similar to that of the increase in liver 5‐HT. The dose‐dependence of the hypoglycaemia induced by LPS was similar to that of the increase in liver 5‐HT. In C3H/HeJ mice, the macrophages and/or lymphocytes of the mice are known to be less responsive to LPS, and both the LPS‐induced hypoglycaemia and increase in 5‐HT were less in these mice than in control mice (C3H/He and ddI mice). These results suggest that macrophages and/or lymphocytes may participate in the induction of hypoglycaemia and the increase in 5‐HT induced by mitogenic substances and LPS. A possible correlation between hypoglycaemia and the increase in hepatic 5‐HT is discussed, although the relationship is not substantiated. 1984 British Pharmacological Society