• Proceedings of the PSK Conference
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• 2001.10a
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• pp.145.1-145.1
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• 2001

• Natural Product Sciences
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• v.23 no.3
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• pp.169-174
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• 2017

The aim of this study was to investigate the effect and action mechanism of quercetin on penile corpus cavernosum smooth muscle (PCCSM). PCCSM precontracted with phenylephrine (Phe) was treated with four different concentrations of quercetin ($10^{-7}$, $10^{-6}$, $10^{-5}$ and $10^{-4}M$). PCCSM were preincubated with N-Nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) to block nitric oxide synthase and guanylate cyclase, respectively. The changes in PCCSM tension were recorded, and cyclic nucleotides in the perfusate were measured by radioimmunoassay. The interactions of quercetin with phosphodiesterase type 5 inhibitors (PDE5-Is) such as sildenafil, udenafil and mirodenafil, were also evaluated. PCCSM relaxation induced by quercetin occurred in a concentrationdependent manner. The application of quercetin to PCCSM pre-treated with L-NAME and ODQ significantly inhibited the relaxation. Quercetin significantly increased cGMP in the perfusate. Furthermore, quercetin enhanced PDE5-Is-induced relaxation of PCCSM. Quercetin relaxed the PCCSM by activating the NO-cGMP signaling pathway, and it may be a therapeutic candidate or an alternative treatment for patients with erectile dysfunction who do not completely respond to PDE5-Is.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.4
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• pp.307-315
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• 2022

Since attaining middle age, many patients suffer from the post-micturition dribble (PMD) syndrome but do not receive proper treatment. This is because the etiology and treatment mechanisms of PMD differ from conventional lower urinary tract symptoms. Several pathophysiologies have been proposed, but the mechanisms we observed are the weakening of the bulbocavernosus muscle and dilation of the urethra due to atrophy of the cavernosal tissue. This study investigates the mechanism of PMD by observing anatomical changes in the corpus cavernosum and urethra. SD male rats were categorized by age into the young rats group (8 weeks old) and the old rats group (24 months or more). The ratio area of the bulbous urethra and corpus cavernosum to the total penis was statistically significant between both groups (P<0.05). Significant differences were obtained between the two groups for restored smooth muscle contents and several other parameters related to PMD mechanisms (nNOS, α-SMA) (P<0.05). The changes in size and parameters of the urethra and corpus cavernosum in young and old rats were confirmed. The results from this study are expected to contribute to the study of PMD in the future.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.5
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• pp.625-630
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• 2013

Erectile dysfunction (ED) is a highly prevalent disorder that affects millions of men worldwide. ED is now considered an early manifestation of atherosclerosis, and consequently, a precursor of systemic vascular disease. Lycii fructus extracts (LFE) were administered for 4 weeks to assess the improving effects on ED. Animals were divided into one normal group and four LFE-treated groups (0, 0.3, 0.6, and 1.2 g/kg). We induced ED in the study animals by oral administration of 20% ethanol instead of water everyday for 4 weeks. This study was designed to investigate the effects of LFE on the mRNA levels of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) expression; NO levels of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP); blood profile; and erectile response of the corpus cavernosum of the rat penis. The libido of the LFE-administered male rats was higher than that of the ethanol control group. The erectile response of the corpus cavernosum was restored after LFE administration, to a level similar to the normal group. In addition, the iNOS in the corpus cavernosum of the male rats administered LFE decreased. In contrast, compared to the control group, LFE-administered male rats showed increased eNOS, NO and cGMP levels in the corpus cavernosum. These results indicate that LFE effectively restored ethanol-induced ED in male rats.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.239-244
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• 2007

The herbal formulation (KH-204) mainly consisted of the fruits of Lycium chinense, Cornus officinalis, Rubus coreanus, Cuscuta chinensis and Schizandra chinensis. We investigated the effects of this herbal formulation on the penile erection and corpus cavernosum of spontaneous hypertensive male Rats (SHR). We used male SHR aged 16 weeks as a model of hypertension. The treatment groups received once a day oral doses KH-204 100 and 300 mg/kg per day for 4 weeks. Distilled water was administered in the control group. To investigate the penile erection, intracavernosal pressure (ICP) and mean arterial pressure (MAP) were recorded in all groups. We analyzed the distribution of NOS by immunohistochemical staining and the expression of nNOS, eNOS concentration in the isolated corpus cavernosum by western blotting. In the control group, ICP/MAP ratio was $14.9{\pm}1.4%$ after pelvic nerve stimulation. ICP/MAP ratio was markedly increased in the treatment group with KH-204 100, 300 mg/kg, compared with control group. Immunohistochemical staining for NOS showed that eNOS and nNOS was stained as brown color. Compared with the control group, NOS activities of KH-204 100, 300 mg/kg were increased significantly. Also the penile expression levels of nNOS, eNOS in KH-204 100, 300 mg/kg treatment group were more increased significantly than control group by western blotting. This study showed that KH-204 enhances the penile erection and the level of eNOS and nNOS expression of penile corpus cavernosum of male SHR.

• Korean Journal of Clinical Pharmacy
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• v.21 no.1
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• pp.1-5
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• 2011

Purpose: 본 연구는 토끼의 음경해면체 조직에 대한 인진쑥의 에탄올 추출물과 그 성분 중의 하나인 scoparone의 효능을 평가하고자 하였다. Methods: 체중이 2.5-3.0 Kg의 New Zealand백색 가토를 사용하여 음경 전체를 골반골로부터 분리하여 요도를 제거한 후 백막을 보유한 음경해면체를 2 mL organ chamber 관류모형에 연결하고, $10^{-5}M$의 phenylephrine을 관류하여 음경해면체를 수축시킨 후 0.1, 0.5, 1, 2 mg/mL의 에탄올 추출물 또는 $10^{-7}$, $10^{-6}$, $10^{-5}$, $10^{-4}M$의 scoparone을 녹인 용액으로 관류시켜 음경의 장력 변화를 측정하였다. 기존의 발기부전 치료제로 사용되는 실데나필에 대한 인진쑥과의 상호작용을 검토하기 위하여$10^{-6}M$의 scoparone과 $10^{-8}M$의 실데나필을 병용 사용 시 음경해면체 조직에 대한 효과도 함께 검토하였다. Results: 인진쑥의 에탄올 추출물은 phenylephrine으로 전처리하여 수축시킨 음경해면체 평활근을 농도 의존적으로 효과적으로 이완시켰으며 scoparone도 음경해면체 조직에 대한 이완작용 또한 농도 의존적으로 강한 효과를 나타내었다. 실데나필로 전처리한 음경해면체 조직에 대한 scoparone의 효과는 scoparone만을 단독으로 관류시킨 조직에서의 효과보다 강하게 나타났으며 실데나필과 scoparone의 병용사용은 실데나필의 효능을 2배 이상 증가시켰다. Conclusions: Scoparone은 실데나필의 음경해면체평활근 작용을 증가시킴으로써 실데나필에 완전히 반응하지 않는 환자들의 발기부전 치료효과 향상에 유용할 것으로 전망된다.

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.471-476
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• 2000

DA-8159, a new phosphodiesterase 5 inhibitor, was assessed for its erectogenic potential by a penile erection test in rats, the relaxation of isolated rabbit corpus cavernosum (CC), and estimation of the intracavernous pressure (ICP) in the anesthetized dog. Oral administration of DA-8159 (0.3 to 1 ${\mu}g/kg$ ) increased the number of erections in rats with increasing dosage, with the highest penile erection index at 10 ${\mu}g/kg$ DA-8159 induced the relaxation of phenylephrine (PHE)-induced contractions in the rabbit CC and decreased the $IC_{50}$ of the nitric oxide donor sodium nitroprusside (SNP) in a dose-dependent fashion. In pentobarbital-anesthetized dogs, the intravenous administration of DA-8159 (1~300 ${\mu}g/kg$ ) potentiated the increase in ICP induced by the intracavernosal SNP in a dose-related manner. These findings suggest that DA-8159 has significant therapeutic potential in the treatment of erectile dysfunction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.847-852
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• 2006

This study was designed to investigate the effects of KH204 on the relaxation response and reproductive function in male. Strips of rabbit corpus cavernosum were prepared for mounting and isometric tension measurement in an organ bath. On cavernosal strips contracted with $1{\times}10^{-6}$ phenylephrine and KH204 was applied in increasing concentrations from 0, 61, 183 and 549 mg/L, causing dose-dependent relaxation. Male Sprague-Dawley rats were orally administered with 61, 183 and 549 mg/kg/day of KH204 for 10 weeks. We examined organ weights, testicular sperm head counts, epididymal sperm counts, motility and morphology. KH204 relaxed rabbit corpus cavernosal strip contracted by $1{\times}10^{-6}$ phenylephrine in a dose-dependent manner. In the male rat, testicular weight was increased significantly in the KH204 treated groups compared with control group. Also in the testicular sperm head counts, epididymal sperm counts were increased significantly in the KH204-treated rats. In conclusion, the data suggest that KH204 could enhance erectile and reproductive function.

• The Korean Journal of Physiology
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• v.29 no.1
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• pp.61-67
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• 1995

The extract of Ginkgo bibloba (EGb) is a complex mixture of natural products from the Ginkgo leaves and clinically used for the treatment of cerebral and peripheral circulatory disturbances due to its combined activity of several vasoactive principles. In this study we investigated the action of EGb and its mechanism in isolated rabbit corporal smooth muscle to evaluate the possibility of using this material as a pharmacoerecting agent. Strips of rabbit corpus cavernosum were mounted in organ chambers to measure isometric tension. EGb began to exert an relaxing effect at 1 mg/ml in the submaximally precontracted muscle strips with phenylephrine $(PHE,\;5{\times}10^{-6}\;M)$; causing concentration-dependent relaxation with maximal effect at $3{\sim}5\;mg/ml$. That relaxation was partially inhibited by removal of the smooth muscle endothelium or by pretreatment with a NO scavenger, pyrogallol $(10^{-4}\;M)$ or the guanylate cyclase inhibitor, methylene blue $(10^{-4}\;M)$. Pretreatment with EGb (3 mg/ml) inhibited PHE- $(5{\times}10^{-6}\;M)$ or KCI- (20 and 40 mM) induced contraction of muscle strip. In calcium-free high potassium solution EGb depressed the basal tone of the depolarized muscle strip and inhibited calcium-induced contraction when $CaCl_2$ $(10^{-4}\;M)$ was added. These results suggest that EGb relaxes rabbit corpus cavernosal smooth muscle through multiple action mechanisms that include increasing the release of nitric oxide from the corporal sinusoidal endothelium, sequestration of intracytosolic calcium, and maybe a hyperpolarizing action.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.873-878
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• 2002

OA-8159, a new Phosphodiesterase (PDE) 5 inhibitor, has exhibited potent erectogenic potential in a penile erection test in rats and anesthetized dogs. In this study, we investigated the mechanism of its erectogenic activity by measuring the activity of OA-8159 against a various PDE isozymes and assessing cGMP and cAMP formation in a rabbit corpus cavernosum in vitro. DA-8159 inhibited the PDE 5 activity in rabbit and human platelets, which the $IC_{50}$ was 5.84$\pm$1.70 nM and 8.25$\pm$2.90 nM, respectively. The $IC_{50}$ of DA-8159 on PDE 1, PDE2, PDE 3 and PDE 6 were 870$\pm$57.4 nM, $101\pm$5 $\mu$M, 52.0$\pm$3.53 $\mu$M and 53.3$\pm$2.47 nM, respectively. This suggests that DA-8159 is a potent, highly selective, competitive inhibitor of PDE 5-catalyzed cGMP hydrolysis. The rates of cGMP hydrolysis catalyzed by human platelets-derived PDE 5 as a function of the cGMP concentration (5~100 nM) and two-fixed DA-8159 concentration (11.3 and 18.8 nM) were investigated in order to characterize the mode of PDE 5 inhibition by DA-8159. DA-8159 increased the apparent 4K_{m}$ value for cGMP hydrolysis but had no effect on the apparent $V_{max}$, indicating a competitive mode of inhibition. DA-8159 increased the cGMP concentrations in the rabbit corpus cavernosum dose dependently. In the presence of sodium nitroprusside (SNP), DA-8159 significantly sti\mulated the accu\mulation of cGMP when compared to the control level. This indicated that the enhancement of a penile erection by DA-8159 involved the relaxation of the cavernosal smooth \muscle by NO-sti\mulated cGMP accu\mulation. In conclusion, DA-8159 is a selective inhibitor of PDE 5-catalyzed cGMP hydrolysis and the enhancement of a penile erection by DA-8159 is mediated by the relaxation of the cavernosal smooth \muscle by the NO-sti\mulated cGMP accu\mulation.