• Archives of Pharmacal Research
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• 제29권8호
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• pp.657-665
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• 2006

We recently reported that dimethylsphingosine (DMS), a metabolite of sphingolipids, increased intracellular pH and $Ca^{2+}$ concentration in U937 human monocytes. In the present study, we found that dimethylphytosphingosine (DMPH) induced the above responses more robustly than DMS. However, phytosphingosine, monomethylphytosphingosine or trimethylsphingosine showed little or no activity. Synthetic C3 deoxy analogues of sphingosine did show similar activities, with the C16 analogue more so than C18. The following structure-activity relationships were observed between DMS derivatives and the intracellular pH and $Ca^{2+}$ concentrations in U937 monocytes; 1) dimethyl modification is important for the DMS-induced increase of intracellular pH and $Ca^{2+}$, 2) the addition of an OH group on C4 enhances both activities, 3) the deletion of the OH group on C3 has a negligible effect on the activities, and 4) C16 appears to be more effective than C18. We also found that W-7, a calmodulin inhibitor, blocked the DMS-induced pH increase, whereas, KN-62, ML9, and MMPX, specific inhibitors for calmodulin-dependent kinase II, myosin light chain kinase, and $Ca^{2+}$-calmodulin-dependent phosphodiesterase, respectively, did not affect DMS-induced increases of pH in the U937 monocytes.

• 분석과학
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• 제28권4호
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• pp.278-287
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• 2015

Phosphodiesterase type 5 inhibitors (PDE-5 inhibitors) are used in the treatment of erectile dysfunction. In recent years, a number of reports have been conducted on dietary supplements contaminated with PDE-5 analogues. In this study, 58 analogues of PDE-5 inhibitors were sorted into five groups: tadalafil, sildenafil, hongdenafil, vardenafil, and other analogues. These analogues were then evaluated using a liquid chromatography-quadrupole-time of flight mass spectrometry (LC-QTOF-MS) electrospray ionization mass method. Each compound has a unique fragmentation ion, which can be easily analyzed qualitatively. The fragmentation pathways of the analogues were elucidated based on the QTOF-MS and MS/MS data. Common ions were confirmed for each group by analyzing the structural characteristics and fragmentation pathways. Specifically, common ions were observed at m/z 169.08 and 135.04 (tadalafil analogues), m/z 311.15 and 283.12 (sildenafil analogues and hongdenafil analogues), and m/z 312.16 and 151.09 (vardenafil analogues). The advantage of this method is that the structure of unknown components can be determined by interpreting the product ions. Hence, the developed method can be used for the identification of unknown compounds. Fragmentation pathways may also aid in the detection and identification of PDE-5 inhibitor analogues.

• The Korean Journal of Physiology and Pharmacology
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• 제2권1호
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• pp.49-54
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• 1998

$Mg^{2+}$ is an important regulator of many cardiac functions. However, regulation of intracellular $Mg^{2+}$ activity in the heart is not well characterized. To assess the effect of histamine $H_2$-receptor stimulation on intracellular $Mg^{2+}$ regulation, changes in extracellular $Mg^{2+}$ concentration were examined under a variety of conditions in perfused guinea pig hearts. $Mg^{2+}$ in the cardiac perfusate was measured by atomic absorbance spectrophotometry. The histamine ($10^{-6}$ M) inuced a marked $Mg^{2+}$ efflux from the heart. The $H_2$-receptor antagonists, cimetidine ($10^{-6}$ M), ranitidined ($10^{-5}$ M), but not a H1-receptor antagonist, diphenhydramine ($3{\times}10^{-6}$ M), completely blocked the histamine-induced $Mg^{2+}$ efflux. The $Mg^{2+}$ efflux could also be induced by forskolin ($3{\times}10^{-6}$ M), 8-Cl-cAMP ($2{\times}10^{-4}$ M), permeable cAMP analogue, or dimaprit, ($10^{-5}$ M). However, the carbachol ($10^{-5}$ M) considerably decreased the efflux of $Mg^{2+}$. In the presence of papaverine ($10^{-5}$ M), a phosphodiesterase inhibitor, dimaprit-induced $Mg^{2+}$ efflux was potentiated. These results suggest that a significant $Mg^{2+}$ efflux from perfused guinea pig heart by histamine can be induced by the histamine $H_2$-receptor stimulation and it is suggested that cytosolic cAMP may be linked.

• 한국동물학회지
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• 제33권2호
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• pp.175-182
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• 1990

참구개구와 옴개구리의 여포를 생체외 배양하면서 progesterone (P$_4$)생성과 난자의 성숙 및 cyclic(cAMP)의 조절작용을 조사하였다.참개구리의 여포에 뇌하수체 추출물(frog pituitary homogenate.FPH)을 처리하면 농도에 의존하여 여포의 P$_4$생성이 증가하였으며 난자의 성숙(핵붕괴)이 일어났다. 이들 여포들을 배양하면서 3시간 간격으로 호르몬이 여포에 축적된 양, 배양액에 분비된 양 및 난자의 성숙율을 조사한 결과 FPH처리군에서 P$_4$는 3-6시간에 최고치 (여포내,약 400pg/여포;분비량,약 800pg/여포)를 나타내었으며 난자의 핵붕괴는 9-12시간에 일어났다. 상기 여포들과 같은 조건으로 배양하면서 forskolin과 3-isobutyl-1-methylxanthine(IBMX)을 배양액에 처리하여 간접적으로 여포내 cAMP의 농도를 높여주면 FPH와 유사한 양사으로 호르몬의 생성을 촉진하였다. 그러나 난자의 성숙은 전혀 일어나지 않았다. 옴개구리의 여포를 배양하면서 FPH를 처리하였을 때는 아무 처리를 하지않은 대조군과 비교하여 거의 P$_4$의 생성을 촉진하지 않았으며 난자의 성숙도 유도하지 못했다, 그러나 이들에게 forskolin과 IBMX를 처리하면 P$_4$의 생성을 현저하게 촉진하여 다량의 P$_4$가 여포와 (약 800pg/여포) 배양액에 (1700pg/여포)축적되었다.

• Journal of Chest Surgery
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• 제33권2호
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• pp.117-124
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• 2000

Background: Nucleoside transport inhibitor(NTI) Keeps AMP, ADP, ATP levels high in myocytes by inhibiting adenosine cataboilsm so that it may preserve the myocardial contractability during ischemia In this study we investigated the effects of cyclic AMP phosphodiesterase inhibor(C-AMP PDSI) and S-P-nitrobenzyl-6 -thioniosine(NBT; a sort of NIT) on myocadial preservation and changes of constituent enzyme. Material and method: Twenty-six isolated rabbit hearts were perfused with Krebs-Henseleit buffer solution for 20 minutes arrested for 20 minutes and ten reperfused for 30 minutes. The following four groups were prepared and hemodynamic changes coronary effluent lactate dehydrogenase (LDH) a-hydroxybutylic accid(a-HBD) levels and myocardial LDH creatine kinase-MB (CK-MB) adenosine deaminase(ADA) a-HBD levels and myocardial LDH creatine kinase-MB (CK-MB) adenosine deaminase(ADA) a-HBD levels were analysed before and after cardiac arest ; Group I(control) ; the heart was only perfused with K-H ; Group II ; the heart was perfused with K-H including C-AMP PDSI(Amrinone 25mg/L); Group III ; the heart was perfused with K-H including NBT(4.19mg/L) ; Group IV ; the heart was perfused with K-H including C-AMP PDSI + NBT. Result : Left venticular developed pressure(LVDP) at 10 minutes of the equilibrium was significantly higher in group III(72.1$\pm$5.3 mmHg p<0.01) and group III(72$\pm$5.6 mmHg P<0.025) as compared with group I (40.8$\pm$4.7mmHg) and LVDP at 20 minutes of the reperfusion was significantly higher in group II(74$\pm$5.3mmHg p<0.01) and group III(72$\pm$5.6mmHg p<0.025) as compared with group I (44.2$\pm$4.6mmHg). Percentage recovery of LVDP at the reperfusion was the highest in group II(123.3%) Percentage recovery of coronary flow at the equilibrium reperfusion were higher in group II(310%, 270%) group III(230%, 290%) group IV(310%, 280%) as compared with group I (100%) respectively. Myocadial LDH level was significant lower in group IV(33495$\pm$1802 IU/gm p<0.04) as compared with group I(48767$\pm$1421 IU/gm) Myocadial CK-MB level was significant higher in group II(74820$\pm$1421 IU/gm) compared with group I (45450$\pm$1737 IU/gm) Myocadial ADA level was significant higher group IV(1215$\pm$8 IU/gm p<0.05) compared with group I(125$\pm$15 IU/gm) but there was no significant difference between group I and group II ,III, IV in changes of coronary effluent LDH, a-HBD levels. Conclusion: C-AMP PDSI solely appears to have a better effect on myocardial preservation after ischemia than NBT but with no synergistic effect and it could keep CK-MB leve high in myocardial tissues.

• The Korean Journal of Physiology and Pharmacology
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• 제2권6호
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• pp.733-742
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• 1998

Background: We have previously reported that not only cGMP but also 8-Br-cGMP or 8-pCPT-cGMP, specific and potent stimulators of cGMP-dependent protein kinase (cGMP-PK), increased basal L-type calcium current $(I_{Ca})$ in rabbit ventricular myocytes. Our findings in rabbit ventricular myocytes were entirely different from the earlier findings in different species, suggesting that the activation of cGMP-PK is involved in the facilitation of $I_{Ca}}$ by cGMP. However, there is no direct evidence that cGMP-PK can stimulate $I_{Ca}}$ in rabbit ventricular myocytes. In this report, we focused on the direct effect of cGMP-PK on $I_{Ca}}$ in rabbit ventricular myocytes. Methods and Results: We isolated single ventricular myocytes of rabbit hearts by using enzymatic dissociation. Regulation of $I_{Ca}}$ by cGMP-PK was investigated in rabbit ventricular myocytes using whole-cell voltage clamp method. $I_{Ca}}$ was elicited by a depolarizing pulse to +10 mV from a holding potential of -40 mV. Extracellular 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate (8-pCPT-cGMP), potent stimulator of cGMP-dependent protein kinase (cGMP-PK), increased basal $I_{Ca}}$. cGMP-PK also increased basal $I_{Ca}}$. The stimulation of basal $I_{Ca}}$ by cGMP-PK required both 8-Br-cGMP in low concentration and intracellular ATP to be present. The stimulation of basal $I_{Ca}}$ by cGMP-PK was blocked by heat inactivation of the cGMP-PK and by bath application of 8-(4-chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer (Rp-pCPT-cGMP), a phosphodiesterase-resistant cGMP-PK inhibitor. When $I_{Ca}}$ was increased by internal application of cGMP-PK, IBMX resulted in an additional stimulation of $I_{Ca}}$. In the presence of cGMP-PK, already increased $I_{Ca}}$ was potentiated by bath application of isoprenaline or forskolin or intracellular application of cAMP. Conclusions: We present evidence that cGMP-PK stimulated basal $I_{Ca}}$ by a direct phosphorylation of L-type calcium channel or associated regulatory protein in rabbit ventricular myocytes.

• Tuberculosis and Respiratory Diseases
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• 제81권4호
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• pp.299-304
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• 2018

Background: Roflumilast is the only approved oral phosphodiesterase-4 inhibitor for the treatment of severe chronic obstructive pulmonary disease (COPD) in patients with chronic bronchitis and a history of frequent exacerbations. The purpose of this study was to examine the incidence of adverse effects associated with roflumilast treatment in a real-world setting. Further, we compared the incidence of adverse effects and the discontinuation rate among patients receiving different doses. Methods: We identified all outpatients diagnosed with COPD at Seoul St. Mary's Hospital between May 2011 and September 2016 and retrospectively reviewed their medical records. Roflumilast was prescribed to patients in doses of $500{\mu}g$ and $250{\mu}g$. Results: A total of 269 COPD patients were prescribed roflumilast in our hospital during the study period. Among them, 178 patients were treated with $500{\mu}g$ and 91 patients were treated with $250{\mu}g$. The incidence of adverse effects was 38.2% in the $500{\mu}g$ group and 25.3% in the $250{\mu}g$ group (p=0.034). The discontinuation rate of roflumilast was 41.6% (n=74) in the $500{\mu}g$ group and 23.1% (n=21) in the $250{\mu}g$ group (p=0.003). When adjusted by age, sex, smoking status, and lung function, $500{\mu}g$ dose was significantly associated with the discontinuation of roflumilast (odds ratio, 2.87; p<0.001). Conclusion: There was a lower incidence of adverse effects and discontinuation among patients treated with $250{\mu}g$ compared with $500{\mu}g$ dose. Further studies regarding the optimal dose of roflumilast are required.

• Clinical and Experimental Reproductive Medicine
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• 제46권4호
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• pp.173-177
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• 2019

Objective: We investigated the clinical characteristics of men with testosterone replacement therapy (TRT)-induced hypogonadism and its effect on assisted reproductive technology (ART) in infertile couples. Methods: This study examined the records of 20 consecutive male patients diagnosed with azoospermia or severe oligozoospermia (< 5 × 10⁶/mL) who visited a single infertility center from January 2008 to July 2018. All patients were treated at a primary clinic for erectile dysfunction or androgen deficiency symptoms combined with low serum testosterone. All men received a phosphodiesterase 5 inhibitor and TRT with testosterone undecanoate (Nebido^®) or testosterone enanthate (Jenasteron^®). Patients older than 50 years or with a chronic medical disease such as diabetes were excluded. Results: The mean age of patients was 37 years and the mean duration of infertility was 16.3 ± 11.6 months. At the initial presentation, eight patients had azoospermia, nine had cryptozoospermia, and three had severe oligozoospermia. Serum follicle-stimulating hormone levels were below 1.0 mIU/mL in most patients. Three ongoing ART programs with female factor infertility were cancelled due to male spermatogenic dysfunction; two of these men had normal semen parameters in the previous cycle. After withholding TRT, serum hormone levels and sperm concentrations returned to normal range after a median duration of 8 months. Conclusion: TRT with high-dose testosterone can cause spermatogenic dysfunction due to suppression of the hypothalamic-pituitary-testicular axis, with adverse effects on infertility treatment programs. TRT is therefore contraindicated for infertile couples attempting to conceive, and the patient's desire for fertility must be considered before initiation of TRT in a hypogonadal man.

• Journal of Pharmaceutical Investigation
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• 제40권2호
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• pp.117-123
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• 2010

Ibudilast, 3-isobutyryl-2-isopropyrazolo[1,5-a]pyridine, is a nonselective inhibitor of cyclic nucleotide phosphodiesterase (PDE). It preferentially inhibits PDE 3A, PDE4, PDE10 and PDE11 as well as a number of the other PDE families, albeit to a lesser extent. Ibudilast is used clinically to treat bronchial asthma and cerebrovascular disorders. Thes e clinical uses are based on the ability of ibudilast to inhibit platelet aggregation, improve cerebral blood flow and attenuate allergic reactions. The purpose of the present study was to evaluate the bioequivalence of two ibudilast capsules, Ketas capsule (Handok Pharmaceuticals Co., Ltd.) and Pinatos capsule (Sam Chun Dang Pharm. Co., Ltd.), according to the guidelines of the Korea Food and Drug Administration (KFDA). The in vitro release of ibudilast from the two ibudilast formulations was tested using KP Apparatus method with various dissolution media. Twenty six healthy male subjects, 23.31${\pm}$1.09 years in age and 70.45${\pm}$8.51 kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single capsule containing 10 mg as ibudilast was orally administered, blood samples were taken at predetermined time intervals and the concentrations of ibudilast in serum were determined using HPLC/UV detector. The dissolution profiles of two formulations were similar in all tested dissolution media. The pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated, and computer programs (Equiv Test and K-BE Test 2002) were utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, Ketas, were 6.99%, -2.48% and 9.93% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 (e.g., log 0.8791~log 1.1861 and log 0.8347~log 1.1199 for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Pinatos capsule was bioequivalent to Ketas capsule.

• 한국식품영양과학회지
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• 제45권4호
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• pp.484-491
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• 2016

본 연구에서는 시네트롤(Sinetrol-XPur)을 유전성 비만 마우스(Obese)에 7주간 식이 투여하여 항비만 효과를 알아보고자 하였다. 시네트롤을 섭취한 유전성 비만 마우스군(Sinetrol low와 Sinetrol high)의 체중증가량은 Obese군에 비하여 유의적으로 감소하였고, 간 무게변화량은 Sinetrol high군에서 Obese군보다 유의적으로 감소하였다. 백색지방의 무게변화량은 Sinetrol high군에서 Obese군보다 유의적으로 감소하였음을 확인하였다. 실험동물의 혈청 지질 함량은 TC, TG, LDL/VLDL-콜레스테롤이 Obese군에 비해 Sinetrol군에서 감소하였고, HDL-콜레스테롤은 유전성 비만군(Obese, Sinetrol low, Sinetrol high) 간에 유의적인 차이가 나타나지 않았다. HDL/LDL ratio를 계산한 결과에서는 Sinetrol군에서 Obese군보다 유의적으로 증가하였음을 확인하였다. 실험동물군의 지방조직에서 비만 관련 유전자들의 발현을 측정한 결과, FAS와 LPL의 발현은 Obese군보다 Sinetrol군에서 감소하였고 HSL의 발현은 유의적인 차이가 나타나지 않았지만, UCP-2의 발현은 Obese군에 비해 Sinetrol high군에서 유의적으로 증가하였음을 확인하였다. 또한 세포 내 cAMP를 측정한 결과 시네트롤 처리 시 농도 의존적으로 cAMP가 증가하였음을 확인하였고, 증가한 cAMP에 의해 UCP-2의 발현이 증가되는 것을 확인하였다. 이러한 결과로부터 시네트롤이 지방 합성과 관련된 유전자 발현의 억제 및 에너지 소비와 관련된 유전자의 발현을 증가시키고 체내 지방의 축적이나 합성을 감소시켜 체중의 증가를 예방하며, 혈중 지질 함량들을 개선하여 항비만 효과가 있는 천연 기능성 식품으로 활용할 수 있을 것으로 기대할 수 있다.