• The Korean Journal of Pharmacology
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• v.6 no.1
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• pp.45-55
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• 1970

It is well known that the uterine contractility is affected by sexual hormone. In this experiment, the authors attempted to study the influences of testosterone and estrogen or the uterine contractility to oxytocics. The contractile sensitivity of the excised uterine muscle of non-castrated and castrated rabbits with testosterone and estrogen 24 hours before experiment is observed respectively. And the cholinesterase activity and electrolytes (Na, K, Ca and Mg) in the uterine muscle are measured in order to study the relationship with contractile sensitivity and those changes. The results obtained were summarized as follows: 1. The contractile effect of spareng on the excised uterine muscle of non-castrated rabbits pretreated with estrogen was markedly increased in small dose, but that of rabbits pretreated with testosterone was significantly increased in large dose, comparing with that of the control group. In castrated rabbits, the contractile sensitivity of the uterine muscle to spareng was significantly increased by pretreatment with estrogen in large dose but it was markedly decreased by pretreatment with testosterone in small dose. 2. The contractile effect of quinine on the excised uterine muscle of non-castrated rabbits pretreated with estrogen was significantly decreased but that of castrated rabbits pretreated with both estrogen and testosterone were markedly increased comparing with that of the control group. 3. The cholinesterase activity in the uterine muscle of non-castrated rabbits was significantly increased by pretreatment with small dose of estrogen or large dose of testosterone, but that of castrated rabbits was markedly decreased by pretreatment with large dose of estrogen. 4. Na and K contents in the uterine muscle of non-castrated rabbits were markedly increased by pretreatment with both estrogen and testosterone, but that of castrated rabbits was significantly increased by pretreatment with small dose of estrogen. 5. Ca content in uterine muscle of non-castrated rabbits was significantly decreased by pretreatment with both large dose of estrogen and testosterone but increased by pretreatment of testosterone. In castrated rabbits, Ca content was significantly decreased by pretreatment with both estrogen and testosterone. 6. Mg content in the uterine muscle of non-castrated rabbits was markedly increased by pretreatment with estrogen and small dose of testosterone, but that of castrated rabbits was significantly decreased by pretreatment with both large dose of estrogen and testosterone.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.381-388
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• 1996

The hemodynamic changes in septic patients produced by inhalational anesthetics are sufficient to threaten the anesthesiologists. The effect of hydroxocobalamin, a vitamin $B_{12a}$, on contractile responses to phenylephrine during administration of inhalational anesthetics were evaluated in aortic ring preparations obtained from LPS-treated rats. The sepsis was developed by intraperitoneal injection of LPS (1.5 mg/kg for l8h) and confirmed by iNOS expression using RT-PCR. Statistical significances (P<0.05) were analyzed by Student's t-test or paired t-test according to data characteristics. The blood pressure, but not heart rate, was decreased in LPS-treated rats as compared to control rats. The contractile response to phenylephrine were dose-dependently increased from the doses of $10^{-8}\;M$ to that of $10^{-5}$ and were attenuated in LPS-treated rings. Both halothane and enflurane, at the doses of 1 MAC, decreased the contractile responses to phenylephrine while isoflurane did not significantly affect the contractile responses. Hydroxocobalamin ($10^{-5}$ M) significantly potentiated the contractile responses in the LPS-treated aortic ring preparations during administration of each inhalational anesthetic or not. From these results, it is suggested that hydroxocobalamin may improve the hemodynamics of septic patients during inhalational anesthesia. Abbreviations: LPS, lipopolysaccharide; RT-PCR, reverse transcription-polymerase chain reaction; MAC, minimum alveolar concentration; iNOS, inducible nitric oxide synthase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.65-72
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• 1993

Ultraviolet light radiation (UVR) did not affect resting tension of isolated thoracic aortae of rats. In aortic rings contracted with phenylephrine, however, UVR produced contractile and relaxant responses in preparations with and without endothelium, respectively. The contractile response was dependent upon the duration $(10{\sim}320\;sec)$ of irradiation, while the relaxation was not. UVR-induced contractions in endothelium-intact rings were significantly potentiated by increasing the concentrations of phenylephrine from $10^{-7}M$ to $10^{-5}M$, and also by addition of $10^{-6}M$ acetylcholine, $10^{-7}M$ isoproterenol and $3.5{\times}10^{-8}M$ nitroglycerine. However, addition of $10^{-6}M$ phentolamine, or $10^{-7}M$ to $10^{-6}M$ LY83583 inhibited the contraction or reversed the contraction to a relaxation. In endothelium-removed preparations the UVR-induced relaxation was attenuated by increasing concentractions of phenylephrine, and by addition of isoproterenol, nitroglycerin, phentolamine or LY83583. These results suggest that UVR produces contractile and relaxant responses in rat thoracic aortae with and without endothelium, respectively, and that the contractile effect results from the inhibition of endothelium-derived relaxing factor (EDRF) release by UVR the inhibition of and/or is in part re-lated to some endothelium-derived contractile factors (EDCFs).

• YAKHAK HOEJI
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• v.31 no.2
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• pp.82-91
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• 1987

The effect of neurotoxic compound 6-hydroxydopamine (6-OHDA) on the change in blood pressure and contractile response of Vas deference by centrally acting agents has been studied in normal and DOCA-salt induced hypertensive rats. The treatment of neonatal rats with 6-OHDA (2$\times$100mg, 250mg Kg$^{-1}$s.c) significantly inhibited the antihypertensive and relaxant effects of Vas deference of clonidine(100$\mu\textrm{g}$ Kg$^{-1}$iv.). The simultaneous administration of desipramine with clonidine into neonatal rats decreased the antihypertensive response of clonidine although treated did not affect the relaxative response of Vas deference. Furthermore, the antihypertensive and relaxant responses of clonidine were reduced by the neonatal rats with 6-OHDA regardless of the administration of desipramine. When neonatal rats were administered with 6-OHDA, the development of DOCA-salt hypertension was prevented. These results suggest that 6-OHDA, clonidine and desipramine hada significant effect on the development and the inhibition of central hypertension mediating the central adrenergic neuron due to their affinity to the central nervous system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.691-697
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• 1999

The pharmacological effects of hydrocooked(110oC, 5 hours) extracts of Bastard halibut have been investigated. All of the hydrocooked extracts showed the measurable contractile effect on the isolated rat duodenum and decreased the normal blood pressure in anesthetized rat. The hydrocooked extracts also exhibited a dose dependent relaxation on the isolated rat aorta precontracted with phenylephrine. Only RM 60 fraction of these extracts had the cytotoxic effect against MCF7 cell(human breast adenocarcinoma cell line), but the other fractions showed neither antibacterial activity nor antitumor activity. Although fish extracts fed group of rat maintained their original body weight, there were no notable changes in the hematological parameters, except that the levels of high density lipoprotein was significantly increased. These results suggest that the hydrocooked extracts of bastard halibut may contain a variety of bioactive materials.

• YAKHAK HOEJI
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• v.50 no.3
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• pp.208-213
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• 2006

Rat aortic ring preparations were mounted in organ baths, exposed to sodium cyanide $(0.01{\sim}1.0\;mM)$ for 10 min, and then subjected to contractile agents or relaxants such as acetylcholine, sodium nitroprusside and isoproterenol. Presence of low concentration of sodium cyanide did not affect the contractile response to KCl or phenylephrine in the aortic rings with intact endothelium or endothelium denuded. Sodium nitroprusside but not acetylcholine or isoproterenol augmented phenylephrine-induced intact or denuded vascular contraction in the presence of low concentration of sodium cyanide. In conclusion, this study provides the evidence concerning the potentiating effect of sodium nitroprusside on the contraction induced by phenylephrine in rat aortic rings regardless of endothelial function.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.2
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• pp.114-121
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• 2012

A novel neuropeptide was isolated from the skin of the snakehead Channa argus using the dorsal retractor muscle (DRM) of a starfish Asterina pectinifera as a bioassay system. The amino acid sequence of the purified peptide was analyzed using automated sequencing and MALDI-TOF mass spectrophotometry. The primary structure of the purified peptide was determined to be Pro-Ala-Leu-Ala-Leu. To investigate the complete primary structure of this peptide, Pro- Ala-Leu-Ala-Leu-OH and Pro-Ala-Leu-Ala-Leu-NH2 were synthesized. The chemical and pharmacological properties of the synthetic peptides were compared with those of the native peptide. Both the native peptide and synthetic Pro-Ala- Leu-Ala-Leu-OH had identical behaviors on the reverse-phase and cation-exchange HPLC chromatograms. Synthetic Pro-Ala-Leu-Ala-Leu-OH showed contractile activity on the DRM, and the threshold concentration of this peptide was approximately $10^{-8}$ M. The maximal contractile effect ($E_{max}$) of this peptide was $294{\pm}45.4$% at $10^{-5}$ M.

• Korean Journal of Veterinary Service
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• v.18 no.3
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• pp.29-35
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• 1995

The effects of prostaglandin $F_2{\alpha}$ were investigated on the uterine smooth muscle motility in the pig. The results were summarized as follows : 1. Prostaglandin $F_2{\alpha}$ caused the contraction of the porcine uterine smooth muscle and the contractile responses increased between the concentration of prostaglandine $F_2{\alpha}$ $10^{-9}$ M and $5{\times}10^{-8}$ M with a dose-dependent manner. 2. The contractile response induced by prostaglandine $F_2{\alpha}$($10^{-8}$ M) was not blocked by pre-treatment with cholinergic receptor blocker, atropine ($10^{-6}$ M). 3. The contractile response induced by prostaglandine $F_2{\alpha}$(10$^{-8}$ M) was not blocked by pretreament with ${\alpha}$-adrenergic receptor blocker, phentolamine($10^{-6}$ M) and ${\beta}$-adrenergic receptor blocker, propranolol($10^{-6}$ M). From these results, it was concluded that the effects of uterine smooth muscle by prostaglandine $F_2{\alpha}$ were only the contraction mediated by prostaglandine TEX>$F_2{\alpha}$ receptor in pig, and that it may not be related to the cholinergic and adrenergic receptor.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2696-2698
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• 2002

In this study, the comparison of the contractile states change at prime mover muscle with that at synergist muscle was executed, while the muscle contracted continuously with isometric contraction. The contractile states of muscle becomes to change when the voluntary contraction of skeletal muscle is progressed continuously. Such the contractile states change is divided into three states in consideration for not only physiological change but also the psychological change by CNS(central nervous system) as "stable state", "fatigue state" and "pain state". As a result of this study, the prime mover muscle is reached "pain state" but the synergist muscle is not reached. Namely the synergist muscle is delayed state than the prime mover muscle. This result judged that although the prime mover muscle have reached a limit when contraction is continued, owing to effect of delayed state of the synergist muscle, the prime mover muscle is endured some more contraction.

• The Korean Journal of Pharmacology
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• v.16 no.1 s.26
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• pp.35-39
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• 1980

In this study, the effects of phenoxybenzamine and related drugs on the action of CCK-PZ and caerulein were examined in isolated gall bladder of guinea pig and higher esophagus strip of fowl. The strips were placed in a bath containing Locke-Ringer solution maintained at $38^{\circ}C$. Oxygen was continuously bubbled through the solution. The contractile response was measured isometrically by a force displacement transducer connected to polygraph. In isolated gall bladder preparation caerulein produced contractile response of CCK-PZ type, but the relative potency on a weight basis was 30 times stronger than CCK-PZ. The response of caerulein or CCK-PZ was not blocked by cholinergic blocking agent and both alpha and beta adrenergic blockades, however, the response of caerulein or CCK-PZ was exceptionally blocked by phenoxybenzamine. In isolated esophagus strip CCK-PZ with high concentration produced marked contraction which was not modified by atropine and other blocking agents, whereas the response was blocked by phenoxybenzamine. These results lead to the conclusion that phenoxybenzamine inherently inhibits the contractile response of CCK-PZ and caerulein on esophagus and other smooth muscle.