scholarly journals Hypothalamic and brainstem sources of pituitary adenylate cyclase-activating polypeptide nerve fibers innervating the hypothalamic paraventricular nucleus in the rat

2006 ◽  
Vol 500 (4) ◽  
pp. 761-776 ◽  
Author(s):  
Mahasweta Das ◽  
Christopher S. Vihlen ◽  
Gabor Legradi
Keyword(s):  
Adenylate Cyclase ◽  
Paraventricular Nucleus ◽  
Nerve Fibers ◽  
Hypothalamic Paraventricular Nucleus ◽  
Pituitary Adenylate Cyclase

scholarly journals Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) as a Growth Hormone (GH)-Releasing Factor in Grass Carp: II. Solution Structure of a Brain-Specific PACAP by Nuclear Magnetic Resonance Spectroscopy and Functional Studies on GH Release and Gene Expression

Endocrinology ◽  
2007 ◽  
Vol 148 (10) ◽  
pp. 5042-5059 ◽  
Author(s):  
Kong Hung Sze ◽  
Hong Zhou ◽  
Yinhua Yang ◽  
Mulan He ◽  
Yonghua Jiang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Adenylate Cyclase ◽  
Grass Carp ◽  
Nerve Fibers ◽  
Pituitary Cells ◽  
Solution Structures ◽  
Central Helix ◽  
Pituitary Adenylate Cyclase ◽  
Nuclear Magnetic

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been proposed to be the ancestral GHRH. Recently, using grass carp as a model for modern-day bony fish, we demonstrated that PACAP nerve fibers are present in close proximity to carp somatotrophs, and mammalian PACAPs can induce GH secretion in carp pituitary cells. To further examine the role of PACAP as a GH-releasing factor in fish, the structural identity of grass carp PACAP was established by molecular cloning. The newly cloned PACAP was found to be a single-copy gene and expressed in the brain but not other tissues. The mature peptides of PACAP, namely PACAP27 and PACAP38, were synthesized. As revealed by nuclear magnetic resonance spectroscopies, carp PACAP38 is composed of a flexible N terminal from His1 to Ile5, an extended central helix from Phe6 to Val26, and a short helical tail in the C terminal from Arg29 to Arg34. The C-terminal helix is located after a hinge region at Leu27 to Gly28 and is absent in the solution structures of PACAP27. The two forms of PACAPs were effective in elevating GH release and GH transcript expression in grass carp pituitary cells. These stimulatory effects occurred with parallel rises in cAMP and Ca2+ entry via voltage-sensitive Ca2+ channels in carp somatotrophs. The present study represents the first report for solution structures of nonmammalian PACAPs and provides evidence that a brain-specific isoform of PACAP in fish can stimulate GH synthesis and release at the pituitary level, presumably by activating the appropriate postreceptor signaling mechanisms.

Pituitary adenylate cyclase-activating polypeptide: occurrence and relaxant effect in female genital tract

1995 ◽  
Vol 269 (1) ◽  
pp. E108-E117 ◽  
Author(s):  
B. R. Steenstrup ◽  
P. Alm ◽  
J. Hannibal ◽  
J. C. Jorgensen ◽  
C. Palle ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Adenylate Cyclase ◽  
Fallopian Tube ◽  
Genital Tract ◽  
Female Genital Tract ◽  
Nerve Fibers ◽  
Female Reproductive Tract ◽  
Human Female ◽  
Pituitary Adenylate Cyclase ◽  
Female Genital

The distribution, localization, and smooth muscle effects of pituitary adenylate cyclase-activating polypeptide (PACAP) were studied in the human female genital tract. The concentrations of PACAP-38 and PACAP-27 were measured by radioimmunoassays, and both peptides were found throughout the genital tract. The highest concentrations of PACAP-38 were detected in the ovary, the upper part of vagina, and the perineum. The concentrations of PACAP-27 were generally low, in some regions below the detection limit and in other regions 1 to 5% of the PACAP-38 concentrations. Immunocytochemistry revealed that PACAP was located in delicate varicose nerve fibers that were most abundant in the internal cervical os, where they mainly seemed to innervate blood vessels and smooth muscle cells. PACAP-38 and PACAP-27 (10(-10)-10(-6) M) caused a concentration-dependent relaxation of the spontaneous activity of the nonvascular smooth muscle strips from fallopian tube and myometrium in vitro. Likewise, both peptides (10(-10)-10(-6) M) caused relaxation of nonrepinephrine (10(-6) M)-precontracted intramyometrial arteries. No effect of the PACAP sequences, PACAP-(6-27), PACAP-(16-38), and PACAP-(18-27), on fallopian tube was observed. The findings suggest a smooth muscle regulatory role of PACAP in the human female reproductive tract.

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