T. Suda et al., NEUROPEPTIDE-Y INCREASES THE CORTICOTROPIN-RELEASING FACTOR MESSENGER-RIBONUCLEIC-ACID LEVEL IN THE RAT HYPOTHALAMUS, Molecular brain research, 18(4), 1993, pp. 311-315
Neuropeptide Y (NPY) has a stimulatory effect on adrenocorticotropin (
ACTH) and corticotropin-releasing factor (CRF) release. In the present
study, to investigate the effect of NPY on CRF synthesis, the effect
of centrally administered NPY on CRF messenger RNA (mRNA) levels in ra
t hypothalamus was examined under pentobarbital anesthesia. The admini
stration of 0.01, 0.1 and 1 nmol of NPY into the lateral ventricle dos
e-dependently Increased the plasma ACTH levels, as well as the levels
of proopiomelanocortin mRNA in the anterior pituitary. The CRF mRNA le
vel in the hypothalamus also increased after administration of 0.1 and
1 nmol of NPY in a dose-dependent manner. The administration of 3 nmo
l of phentolamine or propranolol failed to block 0.1 nmol NPY-induced
ACTH release or 1 nmol NPY-stimulated CRF mRNA levels in the hypothala
mus. These results Indicate that the central administration of NPY inc
reases the CRF mRNA levels in the hypothalamus and the probable CRF re
lease, which increases the proopiomelanocortin mRNA levels and ACTH se
cretion in the anterior pituitary. Therefore, NPY seems to play a phys
iological role in the regulation of the release and synthesis of CRF i
n the hypothalamus.