• Clinical and Experimental Reproductive Medicine
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• v.33 no.1
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• pp.15-23
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• 2006

Objective: Pituitary adenylate cyclase-activating polypeptide (PACAP), a novel hypothalamic neuropeptide, has been suggested to play a role in ovarian folliculogenesis. The present study evaluated the effect of PACAP on the growth of preantral follicles. Methods: Preantral follicles were mechanically isolated from ovaries of 21-day-old rats and cultured in groups for 3 days in serum-free medium in the absence or presence of PACAP-38 ($10^{-6}M$). Results: Treatment with PACAP-38 resulted in an increase in follicle diameter by 75% whereas treatment with follicle stimulating hormone (FSH) increased follicle diameter by 65%. PACAP-38 treatment enhanced the granulosa cell proliferation as measured by thymidine incorporation analysis. Furthermore, the production of progesterone by cultured granulosa cells and GFSHR-17 cell line was stimulated by PACAP-38. Interestingly, PACAP enhanced FSH action on stimulation of SF-1 and aromatase gene expression. Conclusion: The present results demonstrate that PACAP stimulated preantral follicle growth by potentiating proliferation and by stimulating steroidogenesis.

• The Korean Journal of Pharmacology
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• v.28 no.2
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• pp.129-136
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• 1992

As it has been reported that the depolarization-induced acetylcholine (ACh) release is modulated by activation of presynaptic $A_1-adenosine$ heteroreceptor in hippocampus and various lines of evidence indicate the involvement of adenylate cyclase system in $A_1-adenosine$ post-receptor mechanism in hippocampus, it was attempted to delineate the role of adenylate cyclase system in the $A_1-receptor-mediated$ control of ACh release in this study. Slices from rat hippocampus were incubated with $[^3H]-choline$ and the release of the labelled products was evoked by electrical stimulation $(3\;Hz,\;5\;Vcm^{-1},\;2\;ms,\;rectangular\;pulses)$, and the influence of various agents on the evoked tritium-outflow was investigated. $N^6-cyclopentyladenosine$ (CPA), a specific $A_1-adenosine$ receptor agonist, in concentrations ranging from 0.1 to $10\;{\mu}M$, decreased the $[^3H]-ACh$ release in a dose-dependent manner without the changes of basal rate of release. 8-cyclopentyl-1,3-dipropylxanthine $(DPCPX,\;1{\sim}10\;{\mu}M)$, a selective $A_1-receptor$ antagonist, increased the $[^3H]-ACh$ release in a dose-related fashion with slight increase of basal tritium-release. And the CPA effects were significantly inhibited by DPCPX $(2\;{\mu}M)$ pretreatment and the dose-response curve produced by CPA was shifted to the right. The responses to N-ethylmaleimide $(NEM,\;10\;&\;30\;{\mu}M)$, a SH-alkylating agent of G-protein, were characterized by increments of the evoked ACh-release and the basal release, and the CPA effect were completely abolished by NEM pretreatment. Forskolin, a specific adenylate cyclase activator, in concentrations ranging from 0.3 to $10\;{\mu}M$, increased the evoked ACh-release in a dose-dependent manner and the CPA effects were inhibited by forskolin. These results indicate that the $A_1-adenosine$ heteroreceptor plays an important role in ACh-release via nucleotide-binding protein Gi in the rat hippocampus and that the adenylate cyclase system might be participated in this process.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.1-6
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• 2001

Pituitary adenyl ate cyclase activating polypeptide (PACAP) was originally isolated from the ovine hypothalamus and stimulated cAMP production in anterior pituitary cells. It is known that PACAP stimulates cAMP accumulation and contributes to the spermatogenesis and steroidogenesis in rat testis. The principal aim of this study is to determinate the distribution of PACAP mRNA and protein in adult rat testis. For this study, we used in situ hybridization and immunohistochemistry techniques in adult rat testis. PACAP mRNA was stage specifically expressed in seminiferous tubules. Positive signals of PACAP mRNA were detected in the developing germ cells at stages HI-VII of the epithelial cycle. The strongest signals of PACAP mRNA and protein were detected in round spermatids at stages V to early VII of the cycle. These results demonstrate that PACAP which is synthesised in the developing germ cells contributes to the spermatogenesis in rat testis. Thus, we suggest that PACAP plays a critical role in the function of testis.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.5
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• pp.435-440
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• 2015

This study aimed to investigate the effect of pituitary adenylate cyclase-activating peptide (PACAP) on the pacemaker activity of interstitial cells of Cajal (ICC) in mouse colon and to identify the underlying mechanisms of PACAP action. Spontaneous pacemaker activity of colonic ICC and the effects of PACAP were studied using electrophysiological recordings. Exogenously applied PACAP induced hyperpolarization of the cell membrane and inhibited pacemaker frequency in a dose-dependent manner (from 0.1 nM to 100 nM). To investigate cyclic AMP (cAMP) involvement in the effects of PACAP on ICC, SQ-22536 (an inhibitor of adenylate cyclase) and cell-permeable 8-bromo-cAMP were used. SQ-22536 decreased the frequency of pacemaker potentials, and cell-permeable 8-bromo-cAMP increased the frequency of pacemaker potentials. The effects of SQ-22536 on pacemaker potential frequency and membrane hyperpolarization were rescued by co-treatment with glibenclamide (an ATP-sensitive $K^+$ channel blocker). However, neither $N^G$-nitro-L-arginine methyl ester (L-NAME, a competitive inhibitor of NO synthase) nor 1H-[1,2,4]oxadiazolo[4,3-${\alpha}$]quinoxalin-1-one (ODQ, an inhibitor of guanylate cyclase) had any effect on PACAP-induced activity. In conclusion, this study describes the effects of PACAP on ICC in the mouse colon. PACAP inhibited the pacemaker activity of ICC by acting through ATP-sensitive $K^+$ channels. These results provide evidence of a physiological role for PACAP in regulating gastrointestinal (GI) motility through the modulation of ICC activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.333-337
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• 1998

This study was carried out to get infomation on the nitric oxide production ability and its formation mechanisms of polysaccharides extracted from Ganoderma lucidum(PSG) by using murine macrophage cell line. The cultured mycelial cells of Ganoderma lucidum were extracted by alkali, and than neutralized by acid. The extract were passed through the column of DEAE cellulose for more purification. The neutral fraction was concentrated and precipitated with 95% ethanol. The precipitate was lyophilized and PSG was obtained. The immunomodulating effects of PSG on macrophage were performed by using murine macrophage cell line ATCC TIB 71 cells with PSG 0.5mg. PSG alone could not induce the production of nitrite, but it had a significant potential effect on nitrite secretion when the cells were primed and triggered with BCG and Interferon(IFN)-${\gamma}$. Also it was prominent by using calcium channel blocker(verapamil) and adenylate cyclase activator(forskolin).

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.41-41
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• 2004

• Proceedings of the Microbiological Society of Korea Conference
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• 2009.05a
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• pp.123-124
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• 2009

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.303-313
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• 1997

The role of the lower esophageal sphincter(LES) is characterized by the ability to maintain tone and to relax allowing the passage of a bolus. It is known that LES relaxation during swallowing may be induced by the cessation of the tonic neural excitation and the activation of non-adrenergic, non-cholinergic(NANC) inhibitory neurons. Furthermore, it is generally accepted that the relaxation of the smooth muscle is mediated primarily by the elaboration of adenosine 3',5'-cyclic monophosphate(cyclic AMP) and guanosine 3',5'-cyclic mono-phosphate(cyclic GMP) via activation of adenylate cyclase and guanylate cyclase, respectively. It is thus possible that cyclic nucleotides might be a second messenger involved in neural stimulation-induced relaxation of LES, although a relationship between relaxation and changes in cyclic nucleotides after neural stimulation has not been established. The present study was performed to define the participation of cyclic nucleotides in the relaxation of LES of dog in response to neural stimulation. Electrical field stimulation(EFS) caused relaxation of the canine isolated LES strips in a frequency-dependent manner, which was eliminated by pretreatment with tetrodotoxin$(1{\mu}M)$, but not by atropine$(100{\mu}M)$, guanethidine$(100{\mu}M)$ and indomethacin$(10{\mu}M)$. The nitric oxide synthase inhibitors, $N^G-nitro-L-arginine$, $N^G-nitro-L-arginine$ methyl ester and $N^G-monomethyl-L-arginine$ inhibited EFS-induced relaxation. Additions of sodium nitroprusside, a nitrovasodilator and forskolin, a direct adenylate cyclase stimulant, caused a dose-dependent relaxation of LES smooth muscle. Effects of sodium nitroprusside and forskolin were selectively blocked by the corresponding inhibitors, methylene blue for guanylate cyclase and N-ethylmaleimide(NEM) for adenylate cyclase, respectively. Dibutyryl cyclic AMP and dibutyryl cyclic GMP caused a concentration-dependent relaxation of the LES smooth muscle tone, which was not blocked by NEM or methylene blue, respectively. However, both NEM and methylene blue caused significant antagonism of the relaxation in LES tone in response to EFS. EFS increased the tissue cyclic GMP content by 124%, whereas it did not affect the tissue level of cyclic AMP. Based on these results, it is suggested that one of the components of canine LES smooth muscle relaxation in response to neural stimulation is mediated by an increase of cyclic GMP via the activation of guanylate cyclase. Additionally, an activation of cyclic AMP generation system was, in part, involved in the EFS-induced relaxation.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.325-331
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• 2000

The present study was designed to assess the role of spinal adenosine $A_2$ receptor in the regulation of cardiovascular functions such as mean arterial pressure (MAP) and heart rate (HR) in male Sprague-Dawley rats. Rats (250~300 g) were anesthetized with urethane and paralyzed with d-tubocurarine and artificially ventilated. blood pressure and HR were continuously monitored via a femoral catheter connected to a pressure transducer and a polygraph. Drugs were administered intrathecally using injection cannula through guide cannula which was inserted inthrathecally at lower thoracic level through a puncture of an atlantooccipital mombrane. Intrathecal injection of an adenosine $A_2$ receptor agonist, 5'-(N-cyclopropyl)-carboxamaidoadenosine (CPCA; 1, 2 and 3 nmol, respectively), produced a dose-dependent decrease in MAP and HR. Pretreatment with $N^{G}$-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor or 10 nmol of MDL-12,330, an adenylate cyclase inhibitor blocked significantly the depressor and bradycardic effect of 2 nmol of CPCA. But, Pretreatment with 3 nmol of bicuculline, gamma-aminobutyric acid A (GAB $A_{A}$) receptor antagonist, or 50 nmol of 5-aminovaleric acid, GAB $A_{B}$ receptor antagonist did not inhibit the depressor and bradycardic effect of 2 nmol of CPCA. These results indicate that adenosine $A_2$ receptor in the spinal cord plays an inhibitory role in the regulation of cardiovascular function and that the depressor and bradycardic action of adonosine $A_2$ receptor are mediated via the synthesis of nitric oxide and the activation of adenylate cyclase in the spinal cord of rats.s.s.s.

• The Korean Journal of Zoology
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• v.30 no.1
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• pp.1-9
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• 1987

Cyclic AMP (cAMP) was known to play a key role in the regulation of cumulus expansion and oocyte maturation of mammalian cumulus-oocyte complexes (COC's) in vivo and in vitro. The present experiments were conducted to know how intracellular level of cAMP in these cells is controlled. Intracellular cAMP level was modulated by culturing mouse CGC's with an adenylate cyclase stimulator, forskolin, a phosphodiesterase inhibitor, 3-isobutyl-1-methyixanthine (IBMX), human chorionic gonadotrophin (HCG), or follicle stimulating hormone (FSH). The rate of cumulus expansion and germinal vesicle break-down (GVBD) was checked after culture and used as a biological end point. Forskolin in the medium began to stimulate the expansion of the complexes at 1 nM and induced maximum expansion (80~90%) at 0 1~10 $\mu$M. The expansion rate was reduced to 60% when forskolin concentration was increased to 100 $\mu$M. Oocyte GVBD occurred normally (75~82%) in the presence of 10 $\mu$M of forskolin, but partial suppression was appeared at 100 pM of the drug (40%). IBMX also stimulated the expansion from the concentration of 0.01 pM and induced full expansion (81~89%) between the concentration of 1-1000 $\mu$M. Meiotic resumption was occurred normally under 10 $\mu$M of IBMX, but suppressed drastically from the concentration of 100 $\mu$M. The minimum exposing time to hormone or drugs required to trigger cumulus expansion was two minutes with HCG, 15~30 minutes with FSH and fors kolin, and two hours with IBMX. The data presented here seemed to imply that intracellular cAMP level in cumulus cells is regulated by both adenylate cyclase and phosphodiesterase and cumulus expansion is induced by a peak of cAMP while meiotic arrest is maintained by continuous presence of cAMP.