• Journal of Yeungnam Medical Science
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• v.10 no.1
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• pp.144-156
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• 1993

This study was performed to investigate the effect of octreotide on the contractility of rat vas deferens. The smooth muscle strips isolated from the prostatic portion were myographied in isolated organ bath, Electric field stimulation (monophasic square wave, duration: 1 mSec, voltage : 50 V, frequency : 5 Hz or 30 Hz, train: 10 Sec) produced reproducible contraction. The contraction was composed of two component, first phasic component (FPC) and second tonic component (STC). These contractions were abolished by tetrodotoxin ($1{\mu}M$). Octreotide inhibited the field stimulation induced contractions both FPC and STC concentration-dependently. The FPC was decreased by a desentization of purinergic receptor by pretreatment of mATP, and the STC was decreased by pretreatment of reserpine(3 mg/kg, IP) 24 hours before experiments. Octreotide reduced the field stimulation induced contraction in the presence of mATP and of reserpinized muscle strips. The inhibitory effect of octreotide was more potent at 5 Hz than at 30 Hz. Octreotide did not affect basal ton and exogenous norepinephrine- or ATP-induced contraction. These results suggest that octreotide inhibit the contractility of the isolated rat vas deferens by inhibition of the release of neurotransmitters, both ATP and norepinephrine from adrenergic nerve terminal.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.59-67
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• 1982

1) Oxymetazoline, which has been known as an agonist for${\alpha}_1-adrenoceptor$ in various peripheral tissues, caused a pressor response in urethane-anesthetized rabbits when given intra-ventricularly. This pressor response was little affected by pretreatment of rabbits with i.v. guanethidine or chlorisondamine, but it was weakened in rabbits pretreated with either of i.v. phentolamine or guanethidine and chlorisondamine and in guanethidine-pretreated adrenal-ligated rabbits. 2) The pressor to intraventricular oxymetazoline was markedly attenuated by intraventricular pretreatment with prazosin, whereas intraventricular pretreatment with yohimbine or piperoxan did not affect this response. 3) Reserpine-pretreated rabbits also responded with hypertension to intraventricular oxymetazoline, which was markedly diminished by pretreatment with intraventricular prazosin but not affected by yohimbine. 4) Oxymetazoline, given intravenously, produced a pressor response in both whole and spinal rabbits. Intravenous prazosin, phentolamine and yohimbine, in this order, showed greater antagonizing effect to this pressor response. 5) The results indicate that oxymetazoline acts an agonist for ${\alpha}_1-adrenoceptors$ in the rabbit brain participating in the regulation of the blood pressure and in the vasculature of rabbits.

• The Korean Journal of Pharmacology
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• v.27 no.1
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• pp.7-12
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• 1991

We measured the developmental increase of tyrosine hydroxylase(TH) activity and dopamine content with high performance liquid chromatography with electrochemical detection(HPLC-EC) in dissociated cultures of fetal rat brainstem(E14). TH activity and dopamine content increased progressively upto 7 days in vitro, when the effects of various drugs on the dopamine contents were studied. ${\alpha}-Methyl-p-tyrosine$, a TH inhibitor and NSD-1015, an inhibitor of aromatic amiono acid decarboxylase effectively depleted dopamine contents. Dopamine contents were depleted by reserpine and increased by pargyline. When cultures grown for 1 week in control medium were then exposed to tetrodotoxin$(0.1\;{\mu}M$) for 7 days, exposure to tetrodotoxin markedly decreased TH activity. All the above results indicate that dopamine metabolism in the cultered cells reflect reliably the property of brain dopamine metabolism. We suggest that measuring TH activity and dopamine content in brainstem culture with HPLC-EC can be useful tool in the study of pharmacology as well as toxicology of the central dopaminergic system.

• The Korean Journal of Pharmacology
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• v.21 no.2
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• pp.90-98
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• 1985

1) In the study of the forced-swimming test in mice (FSM), the duration of immobility posture was dose-dependently shortened by ${\alpha}_2$-agonists, clonidine and guanabenz. BH-T 933 and oxymetazoline also decreased it . Xylazine rather increased the immobility duration at low dose. 2) ${\alpha}_1$-Agonists, cirazoline, amidephrine and methoxamine, however, showed inconsistent effect on the immobility duration (ID). 3) The decrease in ID by clonidine and guanabenz was antagonized by pretreatment with yohimbine, idazoxan and phentolamine (${\alpha}_2$antagonist), but not by prazosin and corynanthine (${\alpha}_1$-antagonist) .4) The ID in the FSM was shortened dose-dependently by d-amphetamine, and it was also antagonized by yohimbine, but not by prazosin. 5) In the mice pretreated with either ${\alpha}$-methyl-p-tyrosine or reserpine, or with combination of both, the decrease in ID was still evoked by clonidine. 6) When the mice were chronically treated with antidepressants (desipramine and imipramine), or with electroconvulsive shock, clonidine still decreased the ID as it did in the control. 7) These results provided the evidences to hypothesize that the change of the ID in the FSM is closely related with the postsynaptie ${\alpha}_2$-adrenoceptor located on the central noradrenergic neuron body. Furthermore, it is assumed that this escape-directed behavior enhanced by ${\alpha}_2$-adrenoceptor agonist may be the result in some analogy with the incentive of drives which are directed toward the self-preservation.

• The Korean Journal of Pharmacology
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• v.5 no.1
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• pp.65-72
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• 1969

After administration of tetrabenazine (TBZ) 40 mg/kg), the pressor and cardioaccelerator responses of rabbits (whole anesthetized and spinal) to norepinephrine and tyramine were studied. The maxmal potentiation of the pressor activity of norepinephrine developed about 10 hours after TBZ administration. At this time the preesor response to tyramine was not decreased. The cardioaccelerator responses to both amines were not significantly altered. The TBZ-induced supersensitivity to norepinephrine was not increased by additional intravenous reserpine, but it was further increased by giving desipramine. Carbachol, given 2 and 6 hours after TBZ administration, inhibited the development of supersensitivity to norepinephrine by TBZ. The TBZ-induced supersensitivity was discussed in relation to reserpine-induced supersensitivity.

• The Korean Journal of Pharmacology
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• v.20 no.2
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• pp.35-47
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• 1984

Contents of immunoreactive ${\beta}-endorphin$ and maximum of $^3H-morphine$ binding was measured in the rat midbrain homogenates from different subgroups at 24 hour interval over 24 hours. Animals were adapted to the light-dark cycle(L : D, 12: 12) or constant darkness (D : D, 12 : 12) for 3 weeks. After the adaptation, 0.5ml of physiologic saline or drug was administered twice a day for 2 weeks. A highly significant circadian rhythm with the peak$(94.8{\pm}7.7\;fmole/mg\;protein)$ at 06:00 and the nadir $(27.6{\pm}2.4\;fmole/mg\;protein)$ at 18:00 was observed in constant of group. Constant dark or treatment of reserpine, pargyline, imipramine, amphetamine and chlorpromazine modified the diurnal rhythm in the time of peak and nadir, shape, phase amplitude and 24 hour mean of ${\beta}-endorphin$ contents. Opiate receptor binding by $^3H-morphine$ also showed highly significant diurnal change in control and constant dark adapted rats. Statistical analysis by one-way analysis of variance and two-way analysis of variance indicates that the·re are highly significant differences between the diurnal change of ${\beta}-endorphin$ in control and those constant dark adapted and drug treated groups. However diurnal change of Maximum $^3H-morphine$ binding is closely related to the change of ${\beta}-endorphin$ contents. The results are interpreted with regard to the circadian rhythm of beta-endorphin contents, its modification by psychoactive drugs and possible mechanism of diurnal change of opiate receptor in brain.

• The Korean Journal of Pharmacology
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• v.20 no.2
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• pp.23-34
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• 1984

To investigate diurnal variations of opiate receptor binding and its modification by experimental condition or treatment of various centrally-acting drugs, the amount of maximum $^3H-morphine$ binding in rat midbrain homogenates was measured at 4 hour intervals for 24 hours. Animals were conditioned under the controlled L : D, 12 : 12 cycle or D: D, 12 : 12 cycle, for 3 weeks and treated with 0.5 ml of physiological saline or drugs for 2 weeks. A highly significant diurnal rhythm with peak at 22 hour of early dark phase with an amplitude$(0.68{\pm}0.06\;pmole/mg\;protein)$ of +51.1% and nadir $(0.33{\pm}0.03\;mole/mg\;prtein)$ at 18 hour of late light phase with an amplitude of -26.6% was found in control group. 24 tour mean of $^3H-morphine$ binding was $0.45{\pm}0.03\;pmole/mg$ protein respectively. Constant dark adaptation or treatment of reserpine, pargyline, imipramine, amphetamine and chlorpromazine modified the diurnal rhythm in the time of peak and nadir binding shape, phase, amplitude of the diurnal curve and 24 hour mean of $^3H-morphine$ binding. However, Kd values were not changed in all experimental groups : Statistical analysis at times of least and great binding indicates that the differences in $^3H-morphine$ binding were due to changes not in the affinity, but in the number of binding sites. The results are interpreted with regard to the diurnal rhythm of opiate receptor finding. The modes of action of psychoactive drugs are closely related to postulated changes of receptor sensitivity in neuropharmacological aspects.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.737-744
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• 1998

The rhizomes of the Acorus gramineus Soland have been used as sedatives, analgesics, stomachics and anthelmintics in chinese medicine. It is known that the rhizomes of the Acorus gramineus Soland contains the essential oil about 0.5~0.8% and this essential oil contains asarone about 86%. The asarone possess many pharmacological properties similar to those of reserpine and chlorpromazine. Sedative and analgesic effects of essential oil of Acorus gramineus Solaad in mouse was observed. The essential oil of Acorus gramineus Soland decreased the frequency of ambulation on mouse in proportion of concentration. ${\alpha}_2$ receptor antagonist(yohimbine hydrochloride) and opioids receptor antagonist(naloxone hydrochloride) were markedly decreased in frequency of ambulation. The essential oil of Acorus gramineus Soland decreased writhing syndrome in mouse and ${\alpha}_2$ receptor antagonist(yohimbine hydrochloride), opioids receptor antagonist(naloxone hydrochloride) were not increased above effects. In conclusion, these experimental results show that the essential oil of Acorus gramineus Soland have sedative and analgesic effects, but it did not antagonized ${\alpha}_2$ receptor antagonist(yohimbine hydrochloride) and opioids receptor antagonist(naloxone hydrochloride).

• Journal of Chest Surgery
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• v.11 no.3
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• pp.321-325
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• 1978

Coarctation of the aorta was rare condition among the congenital cardiovascular defects in Korea. We experienced a case of coarctatlon of the aorta [postductal type], which was successfully corrected by resection and end to end anastomosis. This patient, 21 years male patient, was admitted to the medical department for evaluation of hypertension, headache and exertional dyspnea during 4 years, and transferred to the department of chest surgery for operation. On physical examination, blood pressures were measured on both extremity, measuring 190/100mmHg on the arm and 100/80mmHg on the leg. Systolic murmur was heard on 2nd to 3rd left intercostal space and left sternal border. On simple chest x-ray, rib notching was seer/on low border of right 3rd and left 4th rib. Final preoperative diagnosis was made by the retrograde aortic catheterization and aortography, which showed the typical configuration of postductal type of coarctation with poststenotic dilatation of the aorta. On 20th, July, 1978, under the general anesthesia with endotracheal intubation, resection of coarctation of the aorta and end to end anastomosis was performed. During clamp for resection, blood pressure of upper extremity was elevated to 200/140mmHg, and controlled by Arfornad. During recovery, blood pressure over 160ramrig in systole was controlled by Reserpine for 8days postoperatively. At discharge, postoperative 8th day, brachial and femoral artery pressure was 145/85 mmHg and 135/80mmHg. After discharge, there was no evidence of specific symptoms and hypertension without antihypertensive drug.

• The Korean Journal of Pharmacology
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• v.1 no.1 s.1
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• pp.53-61
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• 1965

Effects of intraventricular norepinephrine (NE) on rabbit blood pressure and heart rate were investigated. 1) Blood pressure was little affected by small doses of NE (below $500{\mu}g$) but showed marked rise by 1 mg. 2) Heart rate was decreased by intraventriccular NE $(200{\sim}500{\mu}g)$. One mg of NE caused less pronounced bradycardia than with smaller doses. The bradycardia could not be observed in vagotomized or atropinized animals. 3) Intraventricular NE potentiated reflexive bradycardia produced by 5-hydroxytryptamine. 4) Cord-sectioned rabbit showed different responses; the smaller doses $(100{\sim}200{\mu}g)$ produced transitory bradycardia and depression of blood pressure, which followed by tachycardia and pressure rise. The transitory bradycardia and depressor effects were not observed in cord-sectioned and vagotomized rabbit. 5) Treatment of animals with reserpine, guanethidine and hexamethonium changed the effects of intraventricular NE on blood pressure, i.e., in these cases the smaller doses of NE caused maked elevation of blood pressure. 6) From these observations it was inferred that central NE caused stimulation of cardioinhibitory and vasomotor center. The former seemed to be more sensitive to NE than the latter. Susceptibility of the vasomotor center to NE seemed to be influenced by peripheral sympathetic tone.