Studies on neuropeptide Y receptors in a mouse adrenocortical cell line.
The mouse adrenocortical Y-1 cell line has been found to express high affinity binding sites for neuropeptide Y (NPY). Pharmacological studies have shown that these NPY binding sites are of the Y1 type. Reverse transcription-polymerase chain reaction using primers specific for the rat Y1 receptor revealed that the NPY Y1 receptor mRNA is present in Y-1 cells. The Kd of the receptor for NPY was found to be 1.75 +/- 0.20 nM and the Bmax was 265 +/- 18 fmol/mg. The NPY Y1 receptors in this adrenocortical cell line were shown to be coupled to pertussis toxin-sensitive G proteins. Stimulation of Y1 receptors resulted in the inhibition of forskolin- and adrenocorticotropic hormone (ACTH)-stimulated cAMP synthesis. NPY had no effect on basal steroid release from the Y-1 cells. At an ACTH concentration of 0.1 microM, NPY did not affect ACTH-stimulated steroid release, although NPY did inhibit cAMP production under the same hormonal conditions. cAMP profoundly affected the density of the NPY receptors in Y-1 cells. Treatment of the cells with N6,2'-O-dibutyryl-cAMP or ACTH reduced the Y1 receptor density by > 50%. On the other hand the steroid dexamethasone increased the density of Y1 receptors by 35%. Although additional detailed studies are necessary, these results may have interesting implications for the functions of ACTH, steroids, and NPY in the pituitary-adrenocortical axis.
Weng
G
G
Department of Neurology and Neuroscience, Cornell University Medical College, New York, New York 10021, USA.
Yee
F
F
Michl
P
P
Reis
D
D
Wahlestedt
C
C
D000302:Adrenal Cortex / Q000166:cytology / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D017476:Receptors, Neuropeptide Y / Q000378:metabolism*; D013256:Steroids / Q000096:biosynthesis / Q000494:pharmacology
D017476:Receptors, Neuropeptide Y; D013256:Steroids; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D019204:GTP-Binding Proteins