• The Korean Journal of Physiology and Pharmacology
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• 제3권5호
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• pp.507-512
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• 1999

Contribution of prostaglandins $D_2,\;E_2\;and\;I_2\;(PGD_2,\;PGE_2\;and\;PGI_2)$ on the regulation of ATP-sensitive $K^+$ channel $(K_{ATP}\;channel)$ was investigated in isolated single rat ventricular cardiac myocytes using the patch clamp technique. $PGD_2,\;PGE_2\;and\; PGI_2$ did not affect $K_{ATP}$ channel activity in the inside-out patch, but increased channel activity in a dose-dependent manner when the channel activities were attenuated by the administration of 100 ${\mu}M$ ATP to the internal solution in the inside-out patch. Channel activations by the prostaglandins were abolished by 50 ${\mu}M$ glibenclamide, a $K_{ATP}$ channel blocker. Dose-response curves of relative channel activity against the ATP concentrations of internal solution in the inside-out patch were shifted to the right in the presence of those three prostaglandins. The rank order of the channel stimulatory potencies $(as\;IC_{50}\;for\;ATP)$ calculated from the dose-response curves were $PGI_2\;>\;PGD_2\;>\;PGE_2.$ Conductance of the channel was not changed by those three prostaglandins. In conclusion, we suggest that prostaglandins $D_2,\;E_2\;and\;I_2$ are involved in the regulation of $K_{ATP}$ channel activity in certain circumstances, and that those three prostaglandins may cause myocardial relaxation by opening $K_{ATP}$ channels, thus protecting the heart from ischema.

• 약학회지
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• 제36권5호
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• pp.506-511
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• 1992

The Prostaglandins were derivatized rapidly with monodansyl cadaverine as a fluorophore in mild conditions. The carboxylic moiety of prostaglandins was activated with diethyl phosphorocyanidate and successively coupled with fluorophore in dimethylformamide at room temperature. The labeling yield was reached about 95% at 15 min using arachidic acid $(C_{20:0})$ as a test sample. This derivative showed constant fluorescent intensity at $4^{\circ}C$ for 180 days. The derivatives of prostaglandins were shown high solvent selectivity with tetrahydrofuran in reversed-phase column. therefore, these derivatives could be successfully separated on YMC pack A-212(S-5 120A C8) column in tetrahydrofuran-based eluents. The detection limits of these derivatives was ca. 500 fmol and determination limits was ca. 5 pmol as injected amount in fluorescent detection $({\lambda}ex.\;340\;nm,\;{\lambda}em.\;520\;nm)$. In this method, the ranges of recovery and coefficient of variation were $93.6{\sim}102.7%$ and $4.3{\sim}5.8%$, respectively.

• 대한수의학회지
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• 제28권2호
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• pp.311-319
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• 1988

This study was designed to elucidate the effects of iron, a well known catalyst of lipid peroxidation, on the contents of phospholipids, unsaturated fatty acids composed in phospholipid molecules and their derivatives, prostaglandins, and the composition changes of fatty acids contained in phospholipids. Iron decreased the contents of phospholipids and its components of unsaturated fatty acids. Catalytic action of iron decreased the composition rates of linoleate and linolenate composed in phospholipid molecules, while that of arachidonate was inclined to increase. The content of arachidonate was increased and that of prostaglandins was decreased without regard to increase the precursor of prostaglandins. It may be concluded that the decreases of prostaglandins and the increase of arachidonate are due to inhibition of the activities of enzyme systems responsible for prostaglandin synthesis by lipid peroxides produced by the catalyst of iron.

• Clinical and Experimental Reproductive Medicine
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• 제3권1호
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• pp.21-25
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• 1976

• Journal of Nutrition and Health
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• 제24권2호
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• pp.97-103
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• 1991

에탄올이 면역계의 항원전달세포이며, 동시에 감마인터페론 등의 림포카인에 의해 활성화되면 작동세포의 역활을 하는 단핵구-대식세포의 arachildonic acid 대사의 cyclooxygenasc 경로의 프로스타글라딘 생산에 미치는 영향을 연구하기 위하여 감마 인터페론으로 전처치하여 활성화시킨 단핵구와 대조군 단핵구를 사용하여 방사면역측정법으로 프로스타글라딘들을 측정하였다. 건강한 성인의 말초혈액으로 Ficoll-Hypaque용액을 이용한 농도구배법과 젤라틴 피복 플라스크를 이용하여 단핵구를 순수하게 분리한 다음 800단위의 감마 인터페론을 사용하여 3일동안 단핵구를 활성화시켰다. 감마인터페론으로 활성화 시키지 않은 $10^6$개의 단핵구에 100mM,300mM,600mM의 에탄올을 30분간 반응시킨 후 6시간후에 thromboxane B$_2$, PGEB$_2$ 와 6-keto-PGF1$\alpha$ 와 PGE$_2$ 모두 대조군에 비하여 생산이 증가하였다. 감마인터페론으로 전처치한 경우에는 알코올 처치에 관계없이 세가지 프로스타글란딘들 모두 6시간과 24시간에서 대조군보다 감소되었다. 이와같은 성적들로 미루어 볼 때 감마인터페론 처치가 에탄올로 유발한 단핵구 arachidonic acid 대사의 변화를 억제한다고 사료된다.

• Journal of Yeungnam Medical Science
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• 제17권1호
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• pp.1-11
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• 2000

Inhibition of cyclooxygenase(COX), and thus prevention of the formation of prostaglandins, provided a unifying explanation of the therapeutic and toxic actions of nonsteroidal anti-inflammatory drugs (NSAIDs). Recently, the discovery of the two isoforms of COX was made by molecular biologists studying neoplastic transformation in chick embryo cells. The constitutive enzyme, COX-1, is obviously responsible for the production of prostaglandins involved in housekeeping functions such as maintenance of integrity of the gastric mucosa, renal blood flow and platelet aggregation. The inducible form of COX (COX-2) is responsible for the formation of prostaglandins that pathologically affects inflammation, pain and fever. Clearly, all the experimental and clinical data support the hypothesis that the beneficial effects of NSAIDs are due to inhibition of the COX-2 enzyme, whereas the gastrotoxicity is due to inhibition of COX-1. The cox-2/COX-1 ratios of the NSAIDs in common use have been measured and compared with epidemiological data on their side effects. There is little evidence to suggest that one NSAID is clearly more effective than another, But substantial individual variability is present with respect to the pharmacology and pharmacokinetics of these drugs: therefore it is essential to adjust the dosage and choose specific drug to the patient's response.

• Clinical and Experimental Reproductive Medicine
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• 제3권2호
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• pp.3-12
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• 1976

• 대한약리학회지
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• 제13권2호
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• pp.35-39
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• 1977

Cyclic adenosine monophosphate (cAMP), known as a versatile regulator of cellular processes and as a secondary messenger of various hormones and other biogenic agents, such as prostaglandins and histamine, induced prompt and transient antidiuresis followed by mild natriuresis and diuresis, when it was administered into the lateral ventricle of the rabbit in doses ranging from $100\;{\mu}g$ to 1 mg. The initial antidiuresis was brought about by the systemic hypotension, whereas the secondary diuresis seemed to be resulted from the decreased tubular reabsorption of sodium, suggestive of participation of certain endogenous natriuretic agent. This observation suggests that cAMP might be involved in the center-mediated renal action of prostaglandins.

• Asian-Australasian Journal of Animal Sciences
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• 제5권1호
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• pp.29-32
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• 1992

The effects of prostaglandins (PG) and indomethacin, a PG synthesis inhibitor, on ovulation in the perfused fowl ovary were studied. Laying hens were killed by cutting the jugular vein 18-19 h before expected ovulation of the second follicle of a clutch sequence. The cannulated ovary was dissected free and connected with a recycling perfusion apparatus. Agents to be studied for their effects on ovulation were added to the perfusion fluid. $PGF_{2{\alpha}}$ at 0.1 and 1 mg/l induced ovulation, with a success rate of 25% and 30%, respectively. The same doses of $PGE_2$ were effective at 60% and 63%, respectively. Indomethacin partially blocked gonadotrophin-induced ovulation. It is suggested that PGs may play a supportive role in the process of follicular rupture in the domestic fowl.

• 대한약리학회지
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• 제11권1호
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• pp.61-79
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• 1975

The recent knowledge about the effects and the biological roles of prostaglandins(PGs) in the female reproductive system were reviewed on the following view points in detail and the authors also argued on the efficacy and reliability for the induction of labour and therapeutic abortions in midtrimester pregnancy. 1. The actions of PGs on the myometrium in vivo and in vitro and the effects of ovarian hormones on the actions of PGs. 2. The actions of PGs on the fallopian tube. 3. The role of PGs in the initiation of menstrual bleeding and dysmenorrhea. 4. The biological action of PGs on the mechanism of labour and parturition. 5. The efficacy and reliability of PGs for therapeutic abortion in the first and midtrimester pregnancy. 6. The biological role of PGs in the activity and life-span of corpus luteum.