Abstract
PP56 (D-myo-inositol-1, 2, 6-triphosphate) has been reported to specifically inhibit neuropeptide Y-mediated effects in vasculature, heart and brain; because of its reversible but non-competitive antagonism interaction with neuropeptide Y receptor signalling or allosteric modulation of neuropeptide Y binding have been postulated. These possibilities were tested in the present study. PP56 did not affect [ 125I] neuropeptide Y binding to HEL- or SK-N-MC-cells or to porcine splenic membranes. PP56 did not inhibit neuropeptide Y-stimulated Ca 2+ increases in HEL- or SK-N-MC-cells or in cultured porcine aortic vascular smooth muscle cells but if anything slightly enhanced it. PP56 did not antagonize the neuropeptide Y-mediated inhibition of forskolin-stimulated cAMP accumulation in HEL-cells. We conclude that previously reported antagonistic effects of PP56 occur distal to the neuropeptide Y receptor or its second messenger systems Ca 2+ and cAMP or may be restricted to neuropeptide Y receptors in certain model systems.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
