Increase of prolactin mRNA in the rat hypothalamus after intracerebroventricular injection of VIP or PACAP.
Vasoactive intestinal peptide (VIP), the structurally homologous pituitary adenylate cyclase-activating peptide (PACAP) and the pituitary hormone, prolactin (PRL) enhance rapid eye movement sleep (REMS). VIP and PACAP are both inducers of PRL gene expression and release in the pituitary gland. Little is known about PRL regulation in the brain although it is hypothesized that the REMS-promoting activity of i.c.v. administered VIP may be mediated via the activation of cerebral PRL. To test whether VIP or PACAP in fact increase intracerebral mRNA, the peptides (VIP: 30 or 300 pmol; PACAP: 220 pmol) were injected i.c.v. into rats at dark onset. 1 h later, cDNA was synthesized from purified hypothalamic mRNA. Standardized amounts were analysed for PRL using the polymerase chain reaction followed by Southern blotting and hybridization. Compared with beta-actin mRNA levels, both VIP and PACAP increased PRL mRNA levels in a dose-dependent fashion though VIP was more effective on a molar basis. The previously reported alternatively spliced PRL mRNA (lacking exon 4) was not detected. The data support the hypothesis that the REMS-promoting activity of central VIP and PACAP might be mediated by cerebral PRL.
Bredow
S
S
Department of Physiology and Biophysics, University of Tennessee at Memphis 38163.
Kacsóh
B
B
Obál
F
F
Fang
J
J
Krueger
J M
JM
D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D017931:DNA Primers; D018076:DNA, Complementary / Q000096:biosynthesis; D003624:Darkness; D015870:Gene Expression / Q000187:drug effects*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007276:Injections, Intraventricular; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D018377:Neurotransmitter Agents; D015345:Oligonucleotide Probes; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D016133:Polymerase Chain Reaction; D011388:Prolactin / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012895:Sleep, REM / Q000187:drug effects; D014660:Vasoactive Intestinal Peptide / Q000008:administration & dosage / Q000494:pharmacology*
C495403:Adcyap1 protein, rat; D017931:DNA Primers; D018076:DNA, Complementary; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D015345:Oligonucleotide Probes; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D012333:RNA, Messenger; D014660:Vasoactive Intestinal Peptide; D011388:Prolactin