6
Views
19
CrossRef citations to date
0
Altmetric
Original Article

Co-existence and co-secretion of the structurally related peptides VIP and PHI

Pages 43-50 | Published online: 17 Mar 2010
 

Abstract

Using regional specific antisera the concentrations of vasoactive intestinal polypeptide (VIP) and the peptide with N-terminal histidine and C-terminal isoleucine (PHI) in various peripheral tissues and VIP producing tumours were compared with their immuno-histochemical localization. In normal tissue the VIP levels were in general higher than the PHI levels, while the VIP/PHI ratio in tumour tissue varied considerably more than in normal tissue. By immunohistochemistry it was found that VIP and PHI immuno-reactivity occurred in the same autonomic neurons. Gel chromatography revealed that VIP and PHI immunoreactivity in both normal and tumour tissue consisted of two larger molecular forms in addition to “authentic” peptides. These larger molecular forms which had overlapping elution positions probably represent VIP/PHI precursors. In tumour tissue the larger molecular forms constituted a larger proportion of the total immunoreactivity.

Neurally induced relaxation of smooth muscle caused a simultaneous release of VIP and PHI which in combination with the observed relaxatory effect of the peptide suggest a role in the control of smooth muscle activity. Similarly VIP and PHI were co-secreted from tumour tissues as evidenced from elevated plasma levels in patients with VIP producing tumours. In conclusion VIP and PHI seem to co-exist and be co-secreted. Differences in posttranslational processing may create variable content and release of the two peptides.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.