-transparent.png){kind=logo}
This study reports the characterization of receptors for vasoactive intestinal peptide (VIP) on membranes prepared from bovine cerebral arteries. By use of HPLC we prepared two purified monoiodinated VIP radioligands with nearly equivalent cerebral vasorelaxant potency as native VIP, [Tyr(125I)10 )VIP and [Tyr(125I)22]VIP. The former resulted in a higher proportion of specific binding to arterial membranes than the latter and was therefore thought to be the superior radioligand for receptor characterization. The binding of [Tyr(125I)10]VIP to cerebral arterial membranes was saturable, specific, reversible, and dependent on time and temperature. Scatchard analysis suggested the presence of a high- and a low-affinity binding site with KD values of 0.2 and 11 nM and receptor concentrations of 79 and 737 fmol/mg of protein, respectively. The dose-response curves for binding to the VIP receptor by the VIP-homologous peptides PHI, PHM, and rat growth hormone-releasing factor (GRF) were very similar to their dose-response curves for relaxation of cerebral arteries. The order of potency was VIP greater than PHM greater than PHI greater than rat GRF. It is suggested that the characteristics of the vascular VIP binding sites and the close correlation between the binding and vasorelaxant properties of VIP and its related peptides argue for the vascular binding sites being functional receptors for VIP.
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
September 1986,
Brain research,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
September 1997,
Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
April 1991,
Regulatory peptides,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
September 1990,
Experimental eye research,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
June 1990,
European journal of pharmacology,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
March 1994,
Biochimica et biophysica acta,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
December 1979,
FEBS letters,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
April 1984,
Endocrinology,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
January 1987,
The Journal of biological chemistry,
Y Suzuki, and
D McMaster, and
M Huang, and
K Lederis, and
O P Rorstad
January 1995,
Investigative ophthalmology & visual science,
