Chromatographic characterisation of neurotensin-like immunoreactivity in plasma and tissue extracts from hepatoma patients
To determine the nature of the neurotensin-like immunoreactivity produced by some cases of primary liver carcinoma, plasma and tumour neurotensin-like immunoreactivities were characterised in patients with neurotensin-producing hepatoma by chromatographic analysis in conjunction with radioimmunoassay with C- and N-terminally directed antisera. Gel filtration revealed that the majority of neurotensin-like immunoreactivity extracted from the tumour was co-eluted with synthetic neurotensin, whereas a substantial amount of the plasma immunoreactive neurotensin emerged at the void volume. Tumour neurotensin-like immunoreactivity showed a degree of heterogeneity on gel filtration and high pressure liquid chromatography that contrasted with neurotensin-like immunoreactivity extracted from ileal mucosa, suggesting a different post-translational processing of neurotensin within tumour tissue. The ratio of neurotensin 1-8 to neurotensin 1-13 in the patients' plasma suggested that neurotensin was metabolised in a manner similar to that in healthy subjects. The clinical and biological significance of the ectopic production of neurotensin in some hepatomas remains unclear.