Characterization of enkephalin-like material extracted from sympathetic ganglia

The coeliac and superior cervical ganglia of rats, guinea pigs and rabbits contain [met5]-enkephalin (ME) and [leu5]-enkephalin (LE), plus a variable amount of immunoreactive material (against antibodies to ME and LE) with a molecular weight greater than 1800 daltons. This high molecular weight immunoreactive material appears to differ from that present in caudate nucleus because its immunoreactivity fails to increase after trypsinization. The ratio of the two enkephalin contents (ME/LE) is lower in ganglia than in other tissues. LE and ME do not appear to be present in the preganglionic axons. Probably ME, LE and the enkephalinlike material of ganglia are located in cell bodies which send axons outside the ganglia because severing the postganglionic nerve of the superior cervical sympathetic nerve increases the amount of immunoreactive material present in the ganglion. The possibility that ME and LE may be present in cells that store catecholamines can, therefore, be entertained. This is supported by experiments showing that immunoreactive material is also present in adrenal medulla. However, the storage of ME and LE in sympathetic ganglion is not affected by high doses of reserpine.