During studies on the relationship between central biogenic amines and tolerance and physical dependence on morphine, we found that the widely used fluorometric assay for the estimation of brain amines has a number of defects. Some of these were high background values and lack of suitable controls for interfering substances in brain tissue. We therefore developed a set of new assays for the biogenic amines, dopamine, norepinephrine, 5-HT, 5-HIAA and acetylcholine. Using a system consisting of combined gas chromatograph mass spectrometer computeriz, these methods corrected several troublesome points in the fluorometric assays. Part 1 describes the gas chromatograph assays for dopamine, norepinephrine, 5-HT and 5-HIAA and it's use to study the role of biogenic amines in physical dependence of mice on morphine.
At a high dosage, AP-14 depressed emotional behavior elicited by hypothalamic electrical stimulation in rabbits. Using the screening method for central acting drugs, AP-14 equalled that of chlormezanone in mice. AP-14 inhibited to some extent the conditioned avoidance response in rats. Analgesic action was demonstrated by electrical and ultrasonic stimulus methods in mice. Anti-inflammatory action of this drug was found to be more effective than that of aspirin, in rat paw edema induced by carrageenin.
By the application of α-amylase to starch and through the gel filtration of starch hydrolysates, various starch hydrolysates and its filtrates were prepared. To sulfonate starch and sucrose, in addition to various starch hydrolysates and its gel filtrates described above, various sodium saccharide sulfates were prepared. Studies were carried out on these substances regarding the degree of molecular polymerization and the sulfate contents on antipeptic, antiulcerogenic and anticoagulant activities. It was found that 60_??_80 % of the sodium starch hydrolysate sulfate had the strongest activity on antiulcerogenic property. Both polymerization and sulfate contents played a chief role, being the main activities in the appearance of antipeptic, antiulcerogenic and anticoagulant properties. It is also suggested that there is no relation between antipeptic activity in vitro and antiulcerogenic property.
It has been reported in a previous paper that sodium starch hydrolysate sulfate, which has a 60_??_80% degree of hydrolytic reaction, also has an excellant activity on the antiulcerogenic property. In the present work, synthesis of aluminum complex from sodium starch hydrolysate sulfate was carried out, and a synthesis using substituent reaction and that using co-precipitation were formed for application to the study. Comparison among the aluminum complex by substituent reaction and the aluminum complex by co-precipitation showed that aluminum complex by co-precipitation had a superior effect on antiulcerogenic activity in shay rats as compared to the aluminum complex by substituent reaction. Examinations were also carried out on sucrose sulfate-aluminum complex and 60_??_80% starch hydrolysate sulfatealuminum complex by coprecipitation of the various antitulcerogenic properties, antipepsin in vivo and in vivo, and anticoagulant properties. Consequently 60_??_80% starch hydrolasate sulfate-aluminum complex had the strongest activity on antipeptic property in vivo and on various antiulcerogenic properties. Noteworthy is the fact that 60_??_80% starch hydrolysate sulfatealuminum complex produces as a secondary action little effect on the anticoagulant property.
In the mouse, doxapram (DOP) given i. p. caused a pentylentetrazol-like convulsion and the ED50 was 131mg/kg i. p. Pretreatment with pentobarbital did not affect this value. In dogs, rabbits and rats anaesthetized with pentobarbital or urethane, a small dose of DOP (2mg/kg i. v.) caused facilitation of the phrenic nerve activity and a rise in blood pressure. The hypertension caused by administration of DOP was associated with increased spontaneous activity of the cervical sympathetic nerves. In vagotomized rats, dogs or rabbits, decentralized in depressor and sinus nerve, DOP had a slight effect on respiration. The pressor effect of DOP was inhibited by pretreatment with phentolamine or hexamethonium. The same phenomenon was also observed in reserpinized rats.
Exogenously applied acetylcholine causes contractions, depending on the concentration. The contraction was competitively antagonized by atropine and potentiated by physostigmine. On the other hand, exogenously applied phenylephrine, isoproterenol and norepinephrine resulted in relaxation in both preparations. These relaxations were competitively antagonized by adrenergic alpha and beta blocking agents and their combination, respectively. In both preparations, nicotine caused a transient contraction followed by a relaxation. Pretreatment with physostigmine potentiated the contraction in all cases. In 9 out of 22 of the sphincter preparations, and all those of the duodenum, atropine inhibited the contraction caused by nicotine and converted it to a relaxation. In the remaining 13 cases of the atropine-treated sphincter preparations, however, the nicotine-induced response became triphasic: a relaxation followed by a transient slight contraction and a relaxation. The contraction was significantly inhibited by phentolamine or guanethidine. The relaxation caused by nicotine in the presence of atropine was unaffected by propranolol alone, or its combina-tion with phentolamine, bretylium and guanethidine. In both sphincter and duodenum preparations, transmural stimulation caused a transient contraction followed by a relaxation and inhibition of automaticity. Threshold intensity of stimulation was approximately 10V in both preparations. The maximum contractile tension induced by transmural stimulation increased with stimulation intensity until a plateau was attained at 40V. The increase of maximum tension was also seen with stimulation frequency and pulse duration. The time to peak, duration and tension of contraction and the subsequent relaxation of transmural response were compared between the sphincter and duodenum preparations. No difference was observed in any parameter of the responses. Mechanical responses to transmural stimulation and certain autonomic drugs were compared on the isolated sphincter of Oddi and the duodenum from rabbit. Nicotine response in the presence of atropine was the only qualitative difference observed.
Effects of i. v. or i. a. administered naftidrofuryl oxalate (LS-121; 0.1 to 1.0mg/kg) on the regional blood flow of organs of the unanesthetized, curarized cat were studied using the thermoelectrical method. Injection of LS-121 i. v. caused a moderate increase in blood flow in the myocardium and renal cortex, and a marked increase in skeletal muscle, whereas, a very slight increase or no change at all was observed in the cerebral cortex, liver, renal medulla and skin. Injection of the drug La. caused a moderate increase of blood flow in the cerebral cortex and skin, marked increase in the renal cortex and a considerable increase in the skeletal muscle, whereas little or no change was seen in the liver and renal medulla. Increase of blood flow in the skeletal muscle was partially blocked after administration of propranolol, but not after atropine. On the other hand, norepinephrine caused a decrease of blood flow in the skin. The decrease was not blocked after administration of LS-121. Systemic blood pressure began to fall when 0.5mg/kg of the drug was injected, and the fall although more apparent was temporary with a higher dose of the drug. The above mentioned results indicate that LS-121 increases the regional blood flow in organs having mainly a papaverine-like vasodilating action and partially an adrenergic beta effect on the vascular muscle.
Mice were made physically dependent on barbital with 10 days treatment then were utilized for the single dose suppression test and the 2 days substitution test. The relative potency of the drugs substituted for barbital was computed using a scoring system specifically designed to quantify withdrawal behavioral signs in barbital dependent mice and the dependence liability of the drugs was judged by contrasting the potency with the nonspecific CNS depressant effect, estimated as the inhibitory effect on the rotarod adaptability of naive mice. In addition, loss of body wt. during withdrawal was confirmed to be a reliable sign of abstinence.
Activities of various diuretics on experimental nephrotic rats (NER) were compared to those. of normal rats (NWR) with the following results. Spironolactone showed no diuretic activity on NWR but did show a natriuretic effect on NER. Triamterene showed a more potent potassium sparing effect on NER than on NWR and Na+/K+ ratio in the urine was the highest of all diuretics tested. Methyclothiazide showed a most potent diuretic activity on NER and also decreased the excretion of protein and enzymes into the urine of nephrotic animals. Hydrochlorothiazide had a strong chloriuretic effect and decreased proteinuria. Furosemide and Clorexolone had almost the same potent diuretic activity on NER and NWR. Acetazolamide decreased the natriuretic effect and increased the kaliuretic effect on NER. Melarulide showed no diuretic activity but did show an increase of proteinuria on NER. Ethacrynic acid did not have diuretic effects eithers on NER or on NWR. To elucidate the property of diuretics, the experimental rats utilized herein proved adequate.
Diuretic activity and mechanism of a new thiazido diuretic, Penfluzide was compared in rats and dogs to that of structurally similar diuretics, Bendroflumethiazide and Hydroflumethiazide. Penfluzide in an oral dose of 0.1_??_1.0mg/kg caused a strong and dose dependent increase in urine volume as well as in urinary excretion of Na+ and Cl- while that of K+ was only sightly increased in normal rats. In experimental acidotic, alkalotic, nephrotic and spontaneously hypertensive rats, almost the same strong natriuretic activities were seen with Penfluzide, the diuretic activities of the 3 diuretics in rats being in the order of: Penfluzide ≥Bendroflumethiazide>Hydroflumethiazide. In the renal clearance test in dogs, Penfluzide revealed a strong diuretic effect which was not induced by an increased renal plasma flow and ilomerularmfiltration rat by a decrease of sodium and water reabsorption in the tubule. In the renal stop flow test in dogs, the acting site of Penfluzide was observed mainly in the proximal tubule. Inhibition of rat renal Na+-K+-ATPase was not demonstrated with Penfluzide either in vivo or in vivo. Weak hypotensive effects were observed with this drug.
From the screening of a number of new derivatives that have together a side chain of salicylic and anthranilic acid, the title compound, F-1, was selected as the most significant derivative for the anti-edemateous action on carrageenin induced edema. The anti-inflammatory action of F-1 was assessed by detailed analysis. Inhibitory effect of F-1 on acute inflammation (in various tests on increased vascular permeability and acute edema) was more potent than that of aspirin (AS). and similar to that of flufenamic acid (FA) and phenylbutazone (PB). F-1 was less effective than FA and PB in the inhibitory effect on ultraviolet erythema. On subacute inflammation (in tests on sustained edema, proliferation of granulation tissue and adjuvant arthritis), F-1 produced an inhibitory effect, but the activity was slightly less than that of FA and PB. F-1 also showed an anti-edemateous effect on adrenalectomized rats. This fact plus the lack of thymolytic activity suggest a direct action at inflamed sites and not one via a corticoidal intermediary. The ulcerogenic action of F-1 was weaker than that of AS, PB and FA. F-1 presumably does not have uricosuric action as it did not delay the excretion rate of phenol red in rabbits. From the above results, F-1 may be classified as a non-steroidal anti-inflammatory agent.
Certain pharmacological properties of doxapram (DOP; 1-ethyl-(2-morpholinoethyl)-3, 3-diphenyl-2-pyrrolidinon hydrochloride hydrate) were studied in various preparations. Results were obtained as follows: The transient effects such as respiratory stimulation, rise in blood pressure and increase in coronary blood flow were observed with i. v. administration of DOP or dimorpholamine in anesthetized dogs. In the isolated heart of the guinea-pig, the coronary flow was not affected by DOP but both the heart rate and the cardiac contractile force were slightly decreased by DOP. The same results were obtained in the isolated atria of the guinea-pig. The contractions induced by direct (muscle) or indirect (nerve) electrical stimulations in the isolated diaphragm of the rat, were increased by DOP (>10-4g/ml) or dimorpholamine (>10-5g/ml). The isolated trachea of the guinea-pig was relaxed by DOP (10-4 g/ml), while it was contracted by dimorpholamine (10-7_??_2×10-4g/ml). Neither the secretory volume nor the components of the gastric juice were affected by s. c. administration of DOP or dimorpholamine in the Shay rat. The rectal temp. of rabbits was not affected by DOP. Inhibitory effects of DOP and dimorpholamine (both>3×10-4g/ml) on the oxygen consumption of the cortex slice of the guinea-pig were observed.
Several pharmacological and biochemical studies have indicated the interaction of amantadine (Symmetrel), which has proven clinically effective for Parkinsonism, via the central catecholaminergic mechanism. In this study, effect of amantadine on serotonin metabolism was inv. _??_igated in the rat brain. Male Wistar rats weighing 100_??_200g were given amantadine i. p. or together as a mixture with the diet. 5HT content (Bogdanski et al.), 5HIAA content (Giacalone and Valzelli), aromatic amino acid decarboxylase (AADC) activity (Lovenberg et al.) and MAO activity (Wurtman and Axelrod) were estimated in the brain and the other tissues. Significant changes were not found on the entire brain serotonin level or the AADC activity with amantadine treatment (50 and 100mg, i. p.), while one hr following amantadine 100mg/kg, i. p. injection, 5HIAA content and MAO activity were slightly reduced. In 0.01% and 0.05% amantadine fed rats, brain serotonin level was found to be slightly increased. Four days after 0.05% amantadine feeding, MAO activity was significantly reduced while 5HT levels were significantly elevated. Nine days after amantadine, 5HT levels recovered to the initial level. Brain MAO activity was also inhibited in vitro by adding amantadine to incubation medium. MAO inhibition (nialamide 100mg/kg, i. p.) induced 5HT accumulation in the brain was enhanced by amantadine treatment. These findings indicate that amantadine affects not only the central adrenergic but also the serotonergic nervous system.
It has been observed that cardiazol acts facilitatorily, and that the facilitation is provided by suppression of inhibitory mechanisms. The effects of this compound on the spinal cord reflexes have been investigated by this author. The results are as follows: Cardiazol depressed the dorsal activities in all preparations. Regarding ventral activities, the compound accelerated the S. B. S. reflex response, but did not vary either the M. S. R. or the P. S. R. to any great extent in the unanesthetized, immobilized preparation. S. B. S. reflex response was never observed in the spinal preparation. Cardiazol acts not only on the spinal cord itself, but also on the supraspinal mechanisms. The main site of action, however, appeared to be at the supraspinal level, and the mode of action is presumably the suppression of presynaptic inhibition. S. B. S. reflex can be induced according to the depression of presynaptic inhibition and by means of a decrease in the postsynaptic inhibition. Cardiazol may be classified as superior to diazepam-like antagonist drugs, rather than to pentobarbital-like compounds.
The present study was undertaken in order to elucidate the site of drug interaction between digitalis and catecholamines. Experiments were designed to test the effect of digitalis glycoside on catecholamine-induced contraction of vas deferens isolated from guinea pig. Ouabain potentiated the catecholamine-induced contraction of vas deferens. Potentiation by interaction between ouabain and catecholamine was not produced following administration of phenoxybenzamine. In a potassium free medium, ouabain did not produce potentiation of the catecholamine-induced contraction. These results suggest that the interrelated potentiation between catecholamines and ouabain is at the site of the α-adrenergic recepter.
The present study was undertaken to determine whether or not STH influences anesthesia and brain 5-HT increasing actions of pentobarbital and if such is the case does adrenalectomy inhibit the effect of STH. Male Wistar rats were adrenalectomized or sham-operated and injected with STH (growth hormone 2mg/kg per day, i. p.) or its solvent everyday for I week after a postoperative interval of I week. These rats were given a normal diet and 1% saline_??_5% glucose solution. Animals were injected with pentobarbital (50mg/kg i. p.) 18hr after the last injection of STH, and 50% of each group were used to determine the anesthetic effect. The other 50% were decapitated at time intervals of 0min, 15min and 30min after pentobarbital treatment, to determine 5-HT content in the brain. Results are as follows; 1) Chronic administration of STH enhanced “pentobarbital-anesthesia”, although there was no such effect in the adrenalectomized rats. 2) STH administration to adrenalectomized rats induced marked increase of 5-HT in the brain after pentobarbital, although the same treatment for sham-operated rats did not influence the increase as described above.