It has recently been reported that both norepinephrine and dopamine elicit antidiuresis when given intracerebroventricularly. But no inference has been made as to their mechanisms. As dopamine is the immediate precursor of norepinephrine in the biosynthesis of catecholamine, it might be possible that dopamine might act indirectly through increased level of norepinephrine in the brain tissue. To certify whether the dopamine-induced antidiuresis is related to norepinephrine, the influence of phentolamine, a specific alpha-adrenergic blocking agent, on the centrally induced antidiuresis of both norepinephrine and dopamine was investigated in this study. Norepinephrine and dopamine given intraventricularly elicited maximal antidiuresis in doses of 10ug and 500ug, respectively. Phentolamine, administered intravenously in dose of 2mg/kg, abolished the renal effect of norepinephrine given intraventricularly, but did not influence the antidiuresis induced by dopamine. It is suggested that both norepinephrine and dopamine produce antidiuresis when given intracerebroventricularly but their actions are mediated by different mechanisms, and that norepinephrine does not participate in the renal action of dopamine.
Brain ; Dopamine* ; Norepinephrine* ; Phentolamine*

An in vitro pharmacologic study was conducted to investigate the effect of phentolamine on norepinephrine induced contraction of human corpus cavernosum. The isometric muscle tension of corpus cavernosum from 4 potent volunteers were recorded after stimulation with various concentrations of norepinephrine and phentolamine. The results are summarized as follows. Contractile response of corpus cavernosum was observed to begin in the concentration of 10(-6) M and to reach maximal level in the concentration of 10(-4)M norepinephrine. Compared to it, contractile activity of corpus cavernosum to norepinephrine was observed to be gradually decreased in response to pretreatment with phentolamine from 10(-6)M to 10(-4)M. These indicate that norepinephrine causes a dose dependent contraction of corpus cavernosum and phentolamine had a relaxant effect on norepinephrine-induced contraction of corpus cavernosum in dose dependent manner.
Humans ; Muscle Tonus ; Norepinephrine* ; Phentolamine* ; Volunteers

PURPOSE: This study was aimed to compare the erectile response when phentolamine of intracavernous trimix(papaverine, phentolamine, alprostadil) was replaced with chlorpromazine. MATERIALS AND METHODS: A total of 65 patients with erectile dysfunction(63.3+/-9.19 years of age) who had already used intracavernous injection with trimix(4.5+/-2.12 years) were recruited for this study. The erection quality and adverse reactions of chlorpromazine solution were compared with those of trimix. RESULTS: Among 65 patients, the erection quality of the intracavernous chlorpromazine solution compared to that of trimix was worse in 26 patients(40%), better in 8(12.3%) and similar in 31(47.7%) when injected at the clinic. Among 45 patients who used the chlorpromazine solution for intracavernous self-injection at home for more than 3 months, however, the erection quality was worse in 13(28.9%), better in 8(17.8%) and similar in 24(53.3%). Intracavernous chlorpromazine solution-either injected at the clinic or self-injected-showed no significant adverse reaction. CONCLUSIONS: Chlorpromazine could be a safe and effective substitude of phentolamine of trimix.
Alprostadil* ; Chlorpromazine* ; Erectile Dysfunction ; Humans ; Male ; Papaverine* ; Phentolamine

1. It was attempted to clarify the mechanism of the pressor response to raised intracranial pressure in urethane-anesthetized rabbits. 2. Intraventricular clonidine markedly inhibited the pressor response to raised intracranial pressure. 3. Intraventricular regitine antagonized the above mentioned inhibitory effect of clonidine on the pressor response. 4. In reserpine-treated rabbits the pressor response to raised intracranial pressure was not observed, whereas after the intraventricular administration of norepinephrine the pressor response was observed. 5. Intraventricular clonidine inhibited the pressor response that could be observed in the reserpine-treated rabbits after the intraventricular norepinephrine. 6. It is inferred that raised intracranial pressure stimulated some part of the brain to cause the increase of norepinephrine release, resulting in the increase of the sympathetic outflow and the elevation of blood pressure.
Blood Pressure ; Brain ; Clonidine* ; Intracranial Pressure* ; Norepinephrine ; Phentolamine* ; Rabbits*

PURPOSE: To compare the efficacy of Bimix solution (27.3 mg/ml papaverine and 0.9 mg/ml phentolamine) versus Trimix solution (18.8 mg/ml papaverine, 0.6 mg/ml phentolamine and 6.3ug/ml prostaglandin El) in terms of erectile response and complications. MATERIALS AND METHODS: We comparatively analyzed the erectile response and the incidence of pain, prolonged erection (>4 hours), and corporal fibrosis of either medication in the 155 impotent patients who used Bimix solution for intracavernous pharmacotherapy (mean duration: 15 months) and thereafter used Trimix solution (mean 12 months). RESULTS: Erectile response to Trimix solution was significantly better than Bimix solution (p<0.01). The mean dose of Bimix solution was higher than Trimix solution (0.43 ml. vs. 0.34 ml, p<0.05). The severe pain enough for impediment to ntercourse occurred in 6.5% of the Trimix group, while no patient of the Bimix group experienced (p<0.01). The corporal fibrosis was noted in 8.4% of the Trimix group and 16.1% of the Bimix group. However, there was no significant difference between the two groups (p=0.08). The incidence of prolonged erection was significantly lower (p<0.05) in the Trimix group (2.6%) than in the Bimix group (12.3%). A total of 139 patients (89.7%) finally selected Trimix solution. CONCLUSIONS: The Trimix solution was more effective and safer than Bimix solution for the treatment of erectile dysfunction.
Drug Therapy ; Erectile Dysfunction* ; Fibrosis ; Humans ; Incidence ; Male ; Papaverine ; Phentolamine

The effects of intraventricular atropine on the heart rate was investigated in the rabbit. Intraventricular administration of atropine in a dose of 10, 30, 100, or 300 ug produced dose dependant bradycardia. Atropine (100 ug) induced bradycardia was abolished by bilateral vagotomy or intravenous atropine, and inhibited by intravenous propranolol but not by intravenous Regitine. Intraventricular Ecolid or regitine pretreatment diminished the bradycardia induced by intraventricular atropine. From the above results, it is suggested that a central adrenergic mechanism as well as vagal activity plays an important role in the intraventricular atropine-induced bradycardia.
Atropine* ; Bradycardia ; Chlorisondamine ; Heart Rate* ; Heart* ; Phentolamine ; Propranolol ; Vagotomy

The mechanism of serotonin(5-HT) induced contraction and Ca++ mobilization was investigated in right cut from rat aorta. Since it is known that 5-HT can interact with alpha-adrenoceptors in addition to a specific action on 5-HT receptors, the effects alpha-adrenoceptors antagonists on these contractile responses to 5-HT were investigated. The results are as follows : 1) 5-HT produced a strong transient contraction and a concentration dependent contraction. 2) The contractile tension to 5-HT increased with extracellular Ca++ concentration (0.1-5mM). 3) The response produced by rings exposed to Ca++-free PSS was significantly weaker than that produced by rings exposed to calcium containing PSS. When rings of aorta that had been stimulated with 5-HT once for 30 min in Ca++-free TBT were washed 4 times for at least; 20 min in zero Ca++PSS to remove 5-HT, than reexposed to 5-HT in Ca++-free TBT, a phasic contraction was not seen during the second stimulation with 5-HT. 4) The contractile response of 5-HT was inhibited by alpha-adrenergic receptor blocker, phenoxybenzamine and phentolamine. Phentolamine(10(-8)M) antagonized response to high concentrations of 5-HT but responses to low concentrations of 5-HT were not antagonized. 5) The contraction induced by 5-HT in Ca++-free PSS was investigated with phentolamin, methysergide. It was blocked by methysergide but not blocked by phentolamine. 6) These results suggest that 5-HT -induced contraction is the effect of both transmembrane Ca++ influx and the mobilization of intracellular Ca++. Low concentration of 5-HT act on specific 5-HT receptors but high concentration of 5-HT also act on alpha-adreno-receptors.
Animals ; Aorta* ; Calcium ; Methysergide ; Phenoxybenzamine ; Phentolamine ; Rats* ; Receptors, Adrenergic ; Receptors, Serotonin ; Serotonin

Recent reports suggest that the responses of the detrusor muscle to the hypogastric nerve stimulation and some autonomic drugs may not be identical among various species. In this study, the responses of the isolated detrusor muscle strips of the Amyda Japonica and the rabbit to catecholamines were compared, and the type of the adrenergic-receptors was investigated. The results obtained were as follows : 1. Catecholamines (norepinephrine and epinephrine) evoked only contraction in the isolated detrusor muscle of the Amyda Japonica and relaxation in the preparation of the rabbit. 2. The contraction-response in the Amyda Japonica was blocked in the presence of regitine, an adrenergic alpha-receptor blocking agent. 3. The relaxation-response in the rabbit was abolished by pre-treatment with propranolol, an adrenergic beta-receptor blocking agent. 4. Acetylcholine elicited contraction in both of the isolated detrusor muscle strips of the Amyda japonica and the rabbit, and the response was completely blocked in the presence of atropine. 5. The results described above suggest that catecholamines exert excitatory effect on the detrusor muscle of the Amyda japonica as it contains adrenergic alpha-receptors and inhibitory effect on the same preparation of the rabbit as it contains the adrenergic beta-receptors. Key Word : amyda japonica,alpha receptor, beta receptor.
Acetylcholine ; Atropine ; Autonomic Agents* ; Catecholamines ; Phentolamine ; Propranolol ; Receptors, Adrenergic, alpha ; Receptors, Adrenergic, beta ; Relaxation

PURPOSE: Trimix, the mixture of papaverine, phentolamine and PGE1 , has been widely used in intracavernosal therapy for patients with erectile dysfunction. Although several results have been reported in Korean patients using the Trimix, no long-term follow-up studies have been carried out. Therefore, we analysed our long-term follow-up results of Trimix therapy PATIENTS AND METHODS: A total of 216 patients(46.2 years of mean age) with erectile dysfunction underwent intracavernosal self-injection therapy with the Trimix(mixture of papaverine 48mg, phentolamine 2mg, PGE1 18microgram in 2 microliter solution). Once chosen, all patients were tested for an appropriate dosage. They were also given education upto 5 times for an successful self-injection therapy. During follow-up periods, ranging 12 to 34 months, evaluations of the effectiveness and safety of the therapy were made by inteNiewing patients upon their visits to our clinic. RESULTS: The final drop-out rate of cases were 107(49.5%). Most drop-out cases (80 cases) occurred within the first month of the therapy. It was also found that drop-out rate was Inversely correlated with number of attendance at the preself-injection education(p< 0.05). A total of 168 patients failed to attend more than 3 times. The drop-out rate of this group was 55%(92 cases) while 31% in those with more than 3 attendances. A total of 109(50.5%) patients completed longer than 12-month follow-up durations and 85(77%) patients were satisfied with the therapy. Their mean dosage was 0.16 microliter and mean frequency of applications was 5.0 times per month, Although no patient developed corporal fibrosis or infection, other side-effects including prolonged erection(14 cases) and penile pain during intercourse(3 cases) were reported. CONCLUSIONS: Trimix intracavernous injection therapy is minimally invasive, safe and effective for the treatment of patients with erectile dysfunction. While high drop-out rate was thought to be a major problem with this therapy, our results suggest that adequate educations can encourage patients to a certain degree.
Alprostadil ; Education ; Erectile Dysfunction* ; Fibrosis ; Follow-Up Studies* ; Humans ; Male ; Papaverine ; Phentolamine

1) The effects of various alpha-adrenoceptor antagonists on the pressor responses to norepinephrine and phenylephrine were examined in anesthetized rabbits in an attempt to determine whether alpha1 and alpha2-adrenoceptors are located on vascular smooth muscle. 2) yohimbine and piperoxan caused a much greater reduction in the pressor responses(rise of 30~50mmHg) to norepinephrine than to phenylephrine, where as labetalol, thymoxamine, phentolamine and prazosin showed a much greater selectively in reducing the pressor responses to phnylephrine than to norepinephrine. 3) The prssor action of small dose of norepinephrine(rise of 10~20mmHg) was not significantly inhibited by the doses of labetalol, thymoxamine and prazosin which caused marked reduction of the above phenylephrine pressor responses, but yohimbine, piperoxan and phentolamine weakend the action significantly. 4) The results suggest that there are two types, alpha 1 and alpha 2, of postsynaptic alpha-adrenoceptors in the vasculature of rabbits. It seems that phenylephrine produces pressor responses by acting alpha 1-type adrenoreceptors: small doses of norepinephrine by acting on alpha 2-type: large doses of norepinephrine by acting on both types.
Labetalol ; Moxisylyte ; Muscle, Smooth, Vascular ; Norepinephrine* ; Phentolamine ; Phenylephrine* ; Piperoxan ; Prazosin ; Rabbits ; Yohimbine