Decreased content of immunoreactive enkephalin-like peptide in peripheral tissues of spontaneously hypertensive rats

In view of their possible role in the regulation of sympathetic transmission and vascular tone, we have studied the content and chromatographic characteristics of the immunoreactive ME-like peptides in adrenal gland, sympathetic ganglia, salivary gland and hypothalamus of SHR and WKY rats. We report here that the content of these peptides was lower in SHR than WKY rats in all tissues studied, except the hypothalamus. In sympathetic ganglia this decrease was due to a reduction in the ME content and not to that of the high molecular weight (MW) immunoreactive ME-like peptides.