Biomaterial Database

alpha-Trinositol blocks neuropeptide Y-induced inositolphosphate formation in cerebral vessels. 1994

I Jansen, and J You, and L Edvinsson

Department of Experimental Research, General Hospital, Malmö, Sweden.

Neuropeptide Y (NPY) induces contraction of guinea-pig basilar arteries via activation of Y1 receptors. This contraction is blocked by D-myo-inositol-1,2,6-triphosphate (alpha-trinositol). Previous binding studies have shown that alpha-trinositol has no effect at Y1 or Y2 binding sites thus the antagonistic effect should occur at the level of a second messenger. We have examined the effects of NPY on the formation of inositol phosphates (IP) and have looked for an antagonistic effect of alpha-trinositol. NPY (10(-9)-3 x 10-(-7) M) induced strong concentration-dependent contraction of basilar arteries from young guinea-pigs (weight 200-250 g) (Emax: 76.4 +/- 11.1%) but not of arteries from old guinea-pigs (weight > 500 g) (Emax: 2.8 +/- 1.5%). [Pro34]NPY and PYY induced contraction of similar magnitude and potency, whereas NPY13-36 had only a weak effect. This demonstrates an effect via the Y1 type of NPY receptor. The contraction induced by NPY was blocked by alpha-trinositol (p < 0.05). LiCI (2 x 10-4) M), used to inhibit IP breakdown, had no effect on the contraction induced by NPY. NPY (10(-10)-10(-8) M) increased the formation of IP in cerebral vessels from young guinea-pigs from 357 +/- 48 cpm/mg w.w. to 900 +/- 233 cpm/mg w.w. However, there was no alteration in IP formation in cerebral vessels from old guinea-pigs (NPY 10(-9)-10(-7) M). In the presence of alpha-trinositol (10(-8)-10(-6) M) the NPY induced stimulation of IP formation was totally abolished.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007295	Inositol Phosphates	Phosphoric acid esters of inositol. They include mono- and polyphosphoric acid esters, with the exception of inositol hexaphosphate which is PHYTIC ACID.	Inositol Phosphate,Phosphate, Inositol,Phosphates, Inositol
D009478	Neuropeptide Y	A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.	Neuropeptide Y-Like Immunoreactive Peptide,Neuropeptide Tyrosine,Neuropeptide Y Like Immunoreactive Peptide,Tyrosine, Neuropeptide
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001488	Basilar Artery	The artery formed by the union of the right and left vertebral arteries; it runs from the lower to the upper border of the pons, where it bifurcates into the two posterior cerebral arteries.	Arteries, Basilar,Artery, Basilar,Basilar Arteries
D014661	Vasoconstriction	The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.	Vasoconstrictions