Research Project
Grant-in-Aid for Scientific Research (C)
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) could play many roles in mammals. In this study, we used immunochemical techniques to examine the histological and quantitative distribution of PACAP in the central nervous system (CNS) of teleost fish. In addition, high performance liquid chromatographic (HPLC) analysis was performed to characterize the form of PACAP present, while the relationship between PACAP and adenohypophysial hormones was also determined immunohistochemically. We also used enzyme immunoassay to determine the quantity of PACAP in the fish brain, in conjunction with the body mass and gonad somatic index (GSI) of fish. We finally investigated the effects of intracerebroventricular (ICV) and intraperitoneal (IP) administration of synthetic PACAP and related peptides on food intake in the fish. In adult fish, PACAP-like immunoreactive (PACAP-LI) nerve fibers and endings were identified in both the neurohypophysis and adenohypophysis in close … More proximity to pituitary cells containing immunoreactive hormones such as prolactin, somatolactin, the N-terminal peptide of proopiomelanocortin, and N-acetyl endorphin. PACAP-LI nerve fibers were also identified close to immunoreactive GH cells in the pituitary of young fish. The concentration of immunoreactive PACAP in whole brain ranged from 100 to 800 pmol/g wet weight, in fish with weighing 70-480 g. A negative correlation was found between the concentration of immunoreactive PACAP in the whole brain and body weight, but there was no relation between the former and GSI. In reverse-phase HPLC experiments, the predominant form of immunoreactive PACAP eluted closely with synthetic fish PACAP38, while PACAP27-like immunoreactivity was negligible. Cumulative food intake was significantly decreased by ICV injection of PACAP during a 60-min observation period after treatment. IP administration of PACAP also induced a significant decrease in food intake during a 60-min observation period after treatment. Semiquantitative analysis revealed that the expression of mRNAs for PACAP and the PAC_1 receptor was significantly increased by excessive feeding (daily food supply at【greater than or equal】5% of the body weight [BW]) for 7 days. ICV administration of PACAP induced a significant decrease in locomotor activity during the 60-min post-treatment observation period. Semiquantitative analysis revealed that the expression of CRH mRNA was significantly increased by excessive feeding for 7 days. ICV administration of PACAP at a dose sufficient to suppress food intake induced a significant increase in the expression of CRH mRNA. We also examined the effect of α-helical CRH_<9-41>, a CRH antagonist, on the anorexigenic action of PACAP in the goldfish. The inhibitory effect of PACAP was completely suppressed by treatment with α-helical CRH_<9-41>. These results indicate that PACAP also plays many roles in fish. Less
All 2006 2005 2004
All Journal Article (54 results)
Peptides (in press)
Proc.Natl.Acad.Sci. 103
Pages: 7488-7493
Neurosci Lett 399
Pages: 259-263
J.Exp.Biol. 209
Pages: 1207-1216
J.Neuroscience Lett. 18
Pages: 9-13
J.Comp.Physiol. B176
Pages: 203-212
Ann.N.Y.Acad.Sci. (in press)
Proc.Natl.Acad.Sci.USA 103
Neurosci.Lett. 399
J.Neuroendocrinol. 18
Pages: 290-297
J.Comp.Physiol.B 176
Neuroscience Letters (In press)
Peptides (In press)
Journal of Neuroendocrinology (In press)
Annals of New York Academy of Sciences (In press)
Zool.Sci. 22
Pages: 861-868
110006281864
Neurosci.Lett. 386
Peptides 26
Pages: 1611-1616
Pages: 71-76
110006281694
Regul.Pept. 126
Pages: 129-136
Pages: 49-54
Gen.Comp.Endocrinol. 140
Pages: 86-93
Neuroscience Letters 386
Zoological Science 22
Regulatory Peptides 126
Peptides (印刷中)
General and Comparative Endocrinology 140
Trends in Comparative Endocrinology
Pages: 282-285
Pages: 286-288
Pages: 350-353
Pages: 366-368
Trends in Comparative Endocrinology 1
