title: Amine handling properties of human carcinoid tumour cells in tissue culture.
abstract: Carcinoid tumour tissue from two patients was removed from lymph node metastases during surgery. Under sterile conditions the cells were prepared for tissue culture, and grew in clusters for a period of 3-4 weeks. Using immunofluorescence the neoplastic cells were investigated for the presence of various antigens characteristic for other amine handling cell types (adrenal medullary cells, adrenergic neurons, endocrine cells); thus, the presence of catecholamine synthesizing enzymes, 5-HT, MAOs, neuron specific enolase, synaptophysin, chromogranin A and neurofilaments was demonstrated in the carcinoid tumour cells. Also ?-adrenoceptor-like immunoreactivity was present, as was NGF-like immunoreactivity. The amine handling properties were investigated by measuring spontaneous and drug-induced release of 5-HT into the culture medium. Reserpine enhanced the 5-HT levels in the medium, and this was further potentiated by the MAO-inhibitor nialamide or the membrane pump blocker imipramine. The 5-HT synthetic capacity was pronounced, as indicated by measuring the cumulative 5-HT release into the medium after frequent changes of media (at 1 h intervals). If media were changed every 4 d 5-HT levels reached a saturation. In the fluorescence microscope the effect of reserpine in depleting the 5-HT stores was slow; at 24 h of reserpine presence in the media many cells still contained strong 5-HT fluorescence (partly with an agranular appearance) while some cells appeared depleted. Thus, there was a striking difference between individual cells in the reaction to reserpine. ?-Adrenoceptor activation with isoprenaline released 5-HT into the medium in a dose-dependent manner, not blocked by propranolol. This indicates unusual properties of the ?-adrenoceptor, also demonstrated to be present on these neoplastic cells by immunocytochemistry.
authors.affiliation: Department of Surgery I, Sahlgren's Hospital, University of Göteborg, Box 33031, S-400 33 Göteborg, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Wängberg
authors.forename: H
authors.initials: H
authors.lastname: Ahlman
authors.forename: O
authors.initials: O
authors.lastname: Nilsson
authors.forename: K
authors.initials: K
authors.lastname: Haglid
authors.forename: R M
authors.initials: RM
authors.lastname: Denney
authors.forename: A
authors.initials: A
authors.lastname: Dahlström