1-Azacycloalkyl-1,4-benzodiazepin-2-ones with antianxiety-antidepressant actions

A series of 1-azacycloalkyl-1,4-benzodiazepin-2-ones were synthesized from 1-azacycloalkyl-2-benzoylanilines and corresponding imines and then evaluated for their central nervous system activities. Pharmacological data showed that some of these compounds have potent antidepressant properties, as assessed by their antagonism of tetrabenzine (TBZ) induced ptosis and their inhibition of [3H]norepinephrine uptake into rat brain synaptosomes, as well as their moderate antianxiety properties of preventing of pentylenetetrazol (PTZ) convulsion, suppressing conflict behavior, and displacing potential for [3H]diazepam binding. Introduction of a halogen substituent at position 7 of the 1,4-benzodiazepine ring lengthened the anti-PTZ effects, although the peak effect was slightly reduced and clearly enhanced the anti-PTZ and anticonflict properties. Introduction of Cl to the ortho position of the phenyl ring at position 5 greatly reduced the antidepressant properties. The secondary amine function of the azacyclic ring at position 1 was essential for the production of the antidepressant properties. Of these new series, 7-fluoro-5-(2-fluorophenyl)-1,3-dihydro-1-(4-piperidinyl)-2H-1,4-benzodi azepin-2 -one has the potential to become a useful antidepressant drug with a moderate antianxiety property.

Therapeutic efficacy of a new cephamycin, MT-141, in compromised mice

The antibacterial activity of MT-141 against Escherichia coli and Proteus morganii in compromised mice was investigated and compared with that of latamoxef, cefmetazole and cefoxitin. The bactericidal activity of MT-141 in short-term contact with E. coli and P. morganii was markedly enhanced when combined with mouse serum, and the activity of MT-141 was greater than the activities of the three reference drugs. The antibacterial activities of MT-141 in the liver, spleen and kidney of neutropenic and Sarcoma 180 tumor-bearing mice infected with E. coli and P. morganii were superior to the activities of the reference drugs. MT-141 was more potent than cefmetazole and cefoxitin, and similar to latamoxef in potency against systemic P. morganii infection in Sarcoma 180 tumor-bearing mice.

Dexamethasone suppression test in autistic children

A dexamethasone suppression test (DST) was carried out on autistic and other handicapped children to investigate the function of the hypothalamo-pituitary adrenal axis (HPA-axis). The subjects were 19 autistic children consisting of 11 relatively well-developed and eight poorly-developed children. The control groups were 26 normal volunteers, 19 patients with schizophrenia and 15 children with mental retardation (MR) or minimal brain dysfunction (MBD). The DST procedures followed the Carroll method. As a result, all of the normal volunteers and 19 schizophrenic patients showed normal response (suppressor). Nine of the 11 well-developed autistic children exhibited suppressor, while all of the poorly-developed children showed an abnormal response (non-suppressor). Nine of the 10 children with MR and all of the five children with MBD were suppressor. These results suggest that there might be a dysfunction in the HPA-axis of the poorly-developed autistic children.

A novel method to predict the elimination half-lives and the renal excretion mechanisms of cephalosporins

A novel method was proposed to predict the elimination half-lives of cephalosporins from plasma protein binding (unbound fraction, f) and fraction of the dose excreted into urine (f*) on the basis of the following four assumptions. 1) The drug is only distributed to the extracellular fluid, 2) the bound fraction of the drug in plasma is independent of the plasma drug concentration, 3) the binding protein of the drug is albumin, 4) the unbound drug in plasma is excreted by the glomerular filtration and the contribution of active secretion and reabsorption is negligible. The VSS's and t1/2 beta's of MT-141, one of cephalosporins, in rabbits, dogs and healthy human subjects were well predicted, whereas in rats, the prediction of the both values was failed. The t1/2 beta's of various cephalosporins in healthy subjects were calculated from f and f*, in reasonably good agreement with the observed ones, except for some cephalosporins which have been reported to be secreted actively in the renal tubules. Thus, the comparison of the calculated t1/2 beta's with the observed ones makes it possible to presume the renal excretion mechanism. Moreover, this method will be applicable to other drugs which satisfy the above four assumptions.

[Pharmacological studies on a new cephamycin, MT-141. (2) Its effect on preparations of neuromuscular junction, smooth muscle organs and gastro-intestinal system]

The results for pharmacological experiments of MT-141 were as follows; Twitch tension of gastrocnemius muscle evoked by the stimulation of sciatic nerve was slightly reduced with 400 mg/kg MT-141 i.v. and upper doses. As the change was very small, however, it seems that MT-141 has no neuromuscular junction blocking action. Although MT-141 did not show any effects on most of isolated smooth muscle organs, only isolated tracheal muscle was somewhat relaxed with 10(-3) g/ml MT-141. The spontaneous motility of smooth muscle in situ was temporarily increased with 800 mg/kg MT-141 i.v. and upper doses. Two hundred mg/kg MT-141 showed no effect on the value of blood sugar and functions of kidney and liver. Any hemolysis did not appear even in the highest dose of 200 mg/kg MT-141 used in this experiment. From the present results and previous report (Krebe, M. et al., Jap. J. Antibiotics, in press), it seems that MT-141 is promised to be a highly safe and useful antibiotic agent in clinical use.

Cardiovascular effects of a new positive inotropic agent, (-)-(R)-1-(p-hydroxyphenyl)-2-[(3,4-dimethoxyphenethyl)amino]-ethanol (TA-064) in the anesthetized dog and isolated guinea pig heart

The positive inotropic effect of TA-064, (-)-(R)-1-(p-hydroxyphenyl)-2-[(3,4-dimethoxyphenethyl)amino]ethanol, was studied in the anesthetized dog and isolated guinea pig heart. An intravenous administration of TA-064 dose-dependently increased the cardiac contractile force with little effect on blood pressure in dogs. The positive inotropic activity of TA-064 was 1/100 that of isoproterenol and similar to that of dobutamine. This effect of TA-064 was stereospecific, and it was blocked by practolol. Thus TA-064 has beta 1-adrenoceptor agonistic action. The positive inotropic effect of TA-064 was more pronounced than the positive chronotropic effect, compared with those of isoproterenol. Similar effect of TA-064 was observed in the reserpinized dog and in the isolated perfused heart of the guinea pig as well. TA-064 administered intraduodenally at a dose of 0.1 mg/kg increased contractile force by 120% of the control, and the effect lasted for more than 150 min. TA-064 given in the femoral artery demonstrated a very weak vasodilating effect on the artery. TA-064 is an orally active, positive inotropic agent. The selective positive inotropic action of TA-064 may result from its beta 1-adrenoceptor agonistic property.

[Distribution, metabolism and excretion of 14C-MT-141 in rats. I. Distribution, metabolism and excretion after single intravenous administration in male rats]

The distribution, metabolism and excretion of the radioactivity were studied in male rats after the bolus intravenous administration of 14C-MT-141. The biological half-lives obtained from the blood concentration-time curve were 0.43 hour for the data in the first 4 hours and 16.5 hours for the data from 6 hours to 24 hours after the intravenous administration of 14C-MT-141. The radioactivity was excreted mainly into urine, and the cumulative urinary and fecal excretion of the radioactivity were 75.2% and 24.1% of the dose, respectively, within 120 hours after the intravenous administration of 14C-MT-141. The cumulative biliary excretion of the radioactivity was 18% of the dose within 48 hours after the intravenous administration, and 35% of the radioactivity excreted into bile (about 6% of the dose) was reabsorbed from the intestine. The highest concentration of the radioactivity was observed in the kidneys, and also the relatively high concentrations were observed in the liver, plasma and intestine, while the concentrations in the brain, fat and muscle were low. Within 24 hours after the intravenous administration of 14C-MT-141, the radioactivity in the highly distributed organs or tissues was decreased to less than 3% of the values at 5 minutes after the intravenous administration. A small amount of N-acetyl-MT-141 was found in urine and feces as a metabolite.

[The mutagenicity evaluation of MT-141, a new cephamycin]

Mutagenicity of MT-141, a new cephamycin, was evaluated by in vitro and in vivo assays. MT-141 did not induce mutations of the test strains, Escherichia coli WP2 (uvr A) and Salmonella typhimurium TA1535, TA1537, TA1538, TA100 and TA98, with and without metabolic activation in vitro. In bone marrow micronucleus assay with male mice, MT-141 showed no induction of micronucleated polychromatic erythrocyte at 6 hours and 30 hours after administration. In addition MT-141 was found not to cause any dominant lethal effects on male mice for 8 weeks after administration.

[Distribution, metabolism and excretion of 14C-MT-141 in rats. II. Distribution and excretion after multiple intravenous administration in male rats and after single intravenous administration in female rats]

The distribution and tissue accumulation of the radioactivity were studied in male rats after the multiple intravenous administration of 14C-MT-141. The distribution and the placental transfer were also studied using pregnant rats or lactating rats after the single intravenous administration of 14C-MT-141. The radioactive concentration in the fetus was low and the radioactivity was distributed almost uniformly through the fetus body. The peak time of the milk level was 2 hours after the administration and the radioactivity in milk decreased gradually thereafter. The milk levels decreased more slowly than the blood levels did. The blood level after the last dose administered daily for 7 days tended to decrease more slowly, when compared with the single administration. However the blood concentration at 48 hours after the last administration was less than 3 times as high as that after the single administration.

Analysis of bile acids by micro high-performance liquid chromatography with postcolumn enzyme reaction and fluorometric detection

Free and conjugated bile acids in human sera were analyzed by micro high-performance liquid chromatography with detection by an immobilized hydroxysteroid dehydrogenase postcolumn reaction and a spectrofluorometer. Bile acids could be effectively collected on a precolumn, 10 X 0.2 mm I.D., packed with silica-ODS (octadecylsilane), by passing a dilute phosphate solution of a serum through it. The detection limit was 0.13-0.28 pmole for a single-to-noise ratio of 2. An amount of 0.1 ml of serum was enough for analysing each bile acid in it.

[Experimental study on the action mechanism of a new bronchodilator agent, BB-1502]

The action mechanism of the bronchodilator activity of BB-1502 was studied in comparison with aminophylline. Orally administered BB-1502 did not inhibit passive cutaneous anaphylaxis in rats, an immediate allergic reaction of Type I, but strongly protected the same antigen-mediated anaphylactic asthma by the intraduodenal route, the activity being approximately 13 times more potent than that of aminophylline. BB-1502 also inhibited IgG-mediated anaphylactic asthma in guinea pigs by the oral route. Both IgE- and IgG-mediated histamine releases from rat lung were similarly inhibited by BB-1502, the potency being 2--3 times that of aminophylline. Disodium cromoglycate showed specific inhibition of the IgE-mediated reaction. BB-1502 and aminophylline showed nonspecific inhibition of the spasms of guinea pig ileum elicited by histamine, acetylcholine and BaCl2. Both compounds inhibited cyclic AMP and cyclic GMP phosphodiesterases (PDEs) derived from guinea pig organs. BB-1502 specifically inhibited the cyclic AMP PDE of lung and brain origins, while aminophylline showed no such specificity. The results of the present study suggested that the bronchodilator and anti-asthmatic actions of BB-1502 might, at least in part, be due to the regulation of cyclic nucleotide PDEs.

Purification and fluorometric assay of proteinase A from yeast

Proteinase A was purified from commercial baker's yeast to homogeneity by using affinity chromatography. Simple and sensitive fluorometric assay procedures were developed for this enzyme, where Suc-Arg-Pro-Phe-His-Leu-Leu-Val-Tyr-4-methylcoumaryl-7-amide and dimethylcasein were used as synthetic substrate and protein substrate, respectively. Proteinase A cleaved the former substrate at the Leu-Val bond. The extent of the cleavage was monitored by measuring the amount of fluorescent 7-amino-4-methylcoumarine produced by the successive cleavage with an auxiliary enzyme, aminopeptidase M, or by measuring the fluorescence generated by the reaction of newly formed amino groups with fluorescamine. In the assay with the latter substrate, the amounts of newly formed amino groups were measured by the reaction with fluorescamine. The optimal pH of the reaction was 5.0 to 5.5. The methods were applied to the study of the effects of denaturing agents on the activity of proteinase A.

[Pharmacokinetics of a new antitumor antibiotic, neothramycin, after intrapleural administration]

In 5 patients with malignant pleural effusion, neothramycin (NTM) was intrapleurally administered at a dose of 30 mg in 3 cases and 40 mg in 2 cases and the pharmacokinetics was studied by using compartment models. The results were as follows: 1) Pleural levels of NTM were described by a mono-exponential equation and the half-life ranged from 3.45 to 6.48 hr. 2) The time to reach the maximum plasma level was 1 to 2 hr after pleural administration. The maximum levels were 54 to 106.4 ng/ml with the 30 mg dosage and 74.7 to 79.2 ng/ml with the 40 mg dosage, followed by a slow decline, with T1/2 ranging from 6.54 to 17.80 hr. 3) The elimination half-life of NTM in the plasma after intrapleural administration was much longer than that after intravenous administration. This phenomenon can be explained by a "flip-flop model": in this case, the rate of transfer from the pleural space to the plasma was much slower than that of the elimination from the plasma. 4) The parameters, K1 and K2, which were obtained by the deconvolution method, seemed to reflect the transfer of NTM between the pleural space and the plasma. 5) In 3 out of the 4 evaluable cases, an extreme decrease in the pleural fluid volume and suppression of reswelling were observed, including a case found to be negative for tumor cells upon cytodiagnosis.

Cerebral vasodilation and spasmolytic activity of diltiazem in anesthetized animals

The effects of diltiazem on the cerebral blood flow and cerebrovascular spasm were studied in pentobarbital anesthetized animals. In Rhesus monkeys, the common carotid and internal carotid blood flow were measured by an electromagnetic flowmeter. Diltiazem (10-300 micrograms/kg, i.v.) dose-dependently increased both the common carotid and internal carotid blood flow, and the increase in internal carotid blood flow persisted for a longer period than that in the common carotid blood flow. In dogs, regional blood flow in the cerebral cortex (rCBF) was measured by means of the hydrogen gas clearance method. Diltiazem (20 micrograms/kg/min, i.v.) increased rCBF by about 20% of the control during the infusion, and the increase in rCBF was still continued 40 min after the infusion was stopped. In cats, the basilar artery was exposed by craniotomy through the transcervico-transclival approach, and vasospasm was induced by topical administration of 5-HT, PGF2 alpha and incubated blood. Diltiazem, either applied topically to the artery (100 micrograms/ml) or infused continuously into the femoral vein (20 or 40 micrograms/kg/min), suppressed the vasoconstriction evoked by the spasmogen.

[Change of pattern of gastric emptying after selective proximal vagotomy]

The patterns of gastric emptying after selective proximal vagotomy (SPV) and SPV with pyloroplasty (SPV + D) were studed using a liquid labelled with 99mTc-DTPA. By means of on-line computer facility, it was possible to analyse the relative role of the Whole stomach and the antrum within the overall frame work of gastric emptying. In the time/activity curve of the whole stomach, all of 3 groups emptied in exponential curve. Comparing with normal subjects, SPV subjects were tending to empty slowly, while SPV + D subjects were tending to empty rapidly. In the time/activity curve of the antrum, normal and SPV + D subjects had two types of emptying--one was represented in the decreasing curve and another was represented in the increasing-decreasing curve. While SPV subjects had only one type of emptying which was represented in the increasing-decreasing curve. From a consideration of the pattern of gastric emptying curve, SPV subjects had two different emptying states compared with normal subjects--one was the delay of entering the antrum from the fundic side of stomach, and the other was that effective antral emptying did not readily start. While SPV + D kept more neally normal gastric emptying that it of SPV.