[Acute pulmonary embolism following lung resection: report of two cases]

We reported 2 cases of acute pulmonary embolism after resection for lung cancer. A 47-year-old male was admitted to our hospital with ground-glass opacity (GGO) on a chest computed tomography (CT). We performed a right upper lobectomy and node dissection (ND) 2a dissection. Two days after the operation, he developed hypotension and hypoxemia. He was diagnosed as acute pulmonary embolism by chest CT and lung scintigram. A 68-year-old women was performed right S6 segmentectomy for lung cancer. The next day, she complained of sudden chest discomfort and dyspnea. She was diagnosed as acute pulmonary embolism by chest CT. Immediately, we started anticoagration therapy with heparin and their condition were improved. It was very important to early diagnose and start anticoagration therapy immediately for acute pulumonary embolism.

Optimal antidiarrhea treatment for antitumor agent irinotecan hydrochloride (CPT-11)-induced delayed diarrhea

PURPOSE

An antitumor camptothecin derivative CPT-11 has proven a broad spectrum of solid tumor malignancy, but its severe diarrhea has often limited its more widespread use. We have demonstrated from a rat model that intestinal beta-glucuronidase may play a key role in the development of CPT-11-induced delayed diarrhea by the deconjugation of the luminal SN-38 glucuronide, and the elimination of the intestinal microflora by antibiotics or dosing of TJ-14, a Kampo medicine that contains beta-glucuronidase inhibitor baicalin, exerted a protective effect. In the present study, we assessed the efficacy of several potential treatments in our rat model to clarify which is the most promising treatment for CPT-11-induced delayed diarrhea.

METHODS AND RESULTS

Oral dosing (twice daily from days -1 to 4) of streptomycin 20 mg/kg and penicillin 10 mg/kg (Str/Pen), neomycin 20 mg/kg and bacitracin 10 mg/kg (Neo/Bac), both of which inhibited almost completely the fecal beta-glucuronidase activity, or TJ-14 1,000 mg/kg improved the decrease in body weight and the delayed diarrhea symptoms induced by CPT-11 (60 mg/kg i.v. from days 1 to 4) to a similar extent. The efficacy was less but significant in activated charcoal (1,000 mg/kg p.o. twice daily from days -1 to 4). In a separate experiment using rats bearing breast cancer (Walker 256-TC), TJ-14, Neo/Bac, and charcoal at the same dose regimen improved CPT-11-induced intestinal toxicity without reducing CPT-11's antitumor activity. In contrast, oral dosing (twice a day) of cyclosporin A (50 mg/kg), a P-glycoprotein and cMOAT/MRP2 inhibitor or valproic acid (200 mg/kg), a UDP-glucuronosyltranferase inhibitor, exacerbated the intestinal toxicity without modifying CPT-11's antitumor activity.

CONCLUSIONS

The result clearly demonstrated the ability of Neo/Bac, Str/Pen, and TJ-14, less but significant ability of activated charcoal, to ameliorate CPT-11-induced delayed-onset diarrhea, suggesting the treatments decreasing the exposure of the intestines to the luminal SN-38 are valuable for improvement of CPT-11-induced intestinal toxicity. In contrast, the treatments affecting the biliary excretion of CPT-11 and its metabolites might have undesirable results.

Inhibitory effects of formoterol on lipopolysaccharide-induced premature delivery through modulation of proinflammatory cytokine production in mice

Previous studies have demonstrated that formoterol, a beta2-adrenoceptor agonist, has potent tocolytic effects in rats. The aim of the present study was to determine whether formoterol treatment affects proinflammatory cytokine production in a lipopolysaccharide (LPS)-treated premature delivery mouse model. Formoterol was continuously administered by osmotic pump and the number of fetuses in the uteri were counted. Samples of amniotic fluid and plasma were collected 8 and 16 h after systemic administration of LPS. LPS induced premature delivery and an increase in prostaglandin F(2alpha) (PGF(2alpha)), interleukin 1alpha (IL-1alpha), IL-6 and IL-10 in the amniotic fluid, and an increase in IL-6 in plasma. Formoterol blocked all changes except the increase in IL-10. These data indicate that formoterol exerts inhibitory effects on proinflammatory cytokine production, and these effects may play an important role in the prevention of premature delivery.

Tocolytic activity of formoterol against premature delivery in mice

The tocolytic activity of formoterol (eformoterol), a long-acting potent beta(2)-adrenoceptor agonist, was assessed in pregnant mice, with determination of uterine effects on the 15th and 16th days of gestation. For examination in the lipopolysaccharide-induced premature delivery model, osmotic pumps filled with formoterol or saline solution were implanted subcutaneously under the back skin. The mice were sacrificed 18-20 h thereafter, and the numbers of fetuses in the uteri and the newborn were counted. The uteri, amniotic membranes and placenta were also rapidly removed for determination of IL-6 concentrations. Furthermore, the effect of formoterol on IL-6 secretion from mouse amnion cells was determined. Formoterol and ritodrine inhibited contraction responses of isolated mouse uteri and their intravenous administration resulted in lowered uterine motility. Lipopolysaccharide (30 microg mL(-1)/mouse) induced premature delivery, attributable to increased IL-6 secretion, and formoterol suppressed this. Doses of 5-500 microg/mouse thus reduced the number of prematurely delivered newborn, and 50 microg/mouse also depressed IL-6 secretion. On histopathologic analysis, the marked oedema and slight haemorrhage in the mouse cervix induced by lipopolysaccharide were reduced by administration of the beta(2)-adrenoceptor agonist. Neither formoterol (10(-7)-10(-5) M) nor ritodrine (10(-7)-10(-5) M) influenced spontaneous secretion of IL-6 in amnion cells. However, at 10(-7) and 10(-5) M, and 10(-6) and 10(-5) M, respectively, they inhibited lipopolysaccharide-induced IL-6 secretion and this inhibitory effect was competitively reversed by addition of ICI-118,551 (beta(2)-adrenoceptor antagonist), but not atenolol (beta(1)-adrenoceptor antagonist). These findings strongly suggest that formoterol can suppress premature delivery mediated by its actions on IL-6 secretion.

A comparative study of the fluoroquinolone antibacterial agents on the action potential duration in guinea pig ventricular myocardia

We examined the effects of ten fluoroquinolone antibacterial agents, levofloxacin, sitafloxacin, trovafloxacin, ciprofloxacin, gemifloxacin, tosufloxacin, gatifloxacin, grepafloxacin, moxifloxacin and sparfloxacin, on action potentials recorded from guinea pig ventricular myocardia. Sparfloxacin prolonged action potential duration (APD) by about 8% at 10 microM and 41% at 100 microM. Gatifloxacin, grepafloxacin and moxifloxacin also prolonged APD at 100 microM by about 13%, 24% and 25%, respectively. In contrast, levofloxacin, sitafloxacin, trovafloxacin, ciprofloxacin, gemifloxacin and tosufloxacin had little or no APD-prolonging effect at concentrations as high as 100 microM. These findings suggest that there are differences in potency to prolong QT interval among the fluoroquinolones.

Differential response of mast cells separated from various organs and basophils of dogs to the fluoroquinolone antimicrobial levofloxacin

Histamine releases induced by the fluoroquinolone antimicrobial levofloxacin (LVFX) were investigated using mast cells separated from various organs and peripheral basophils of dogs, being the most susceptible species to quinolone derivatives, in both in vivo and in vitro systems. An intravenous infusion of LVFX at 30 mg/kg over a 30-min period produced endogenous histamine release from 5 min, and a maximum at 30 min, in which the plasma LVFX concentration was approximately 50 microM. A close correlation (r = 0.87, n = 20) between histamine and LVFX concentrations in plasma during the infusion was observed. In the in vitro study, LVFX at 30 microM or more caused histamine release from mast cells separated from the liver and skin, but not from the gastric mucosa, lung, and peripheral basophils. More exactly, the liver mast cells were most susceptible to LVFX among the organs tested. On the other hand, compound 48/80, a prototype histamine liberator, elicited the histamine release from the liver or skin mast cells at 10 microg/ml, and the calcium ionophore A23187 at 1 microM exhibited the histamine release from the mast cells derived from all organs examined. Histochemical analysis revealed that the liver and skin mast cells had positive reaction for both alcian blue and safranin staining, but the gastric mucosa and lung mast cells were only positive for alcian blue staining, indicating that LVFX preferably activated the connective tissue-type mast cells rather than the mucosal-type mast cells. The degranulation of the liver and skin mast cells brought about by either LVFX or compound 48/80, unlike the calcium ionophore A23187, was blocked by pretreatment with pertussis toxin, suggesting the involvement of pertussis toxin-sensitive G proteins. The results obtained from the canine experiments strongly suggest that LVFX induces histamine release from the connective tissue-type mast cells distributed mainly in the liver, somewhat in the cutaneous tissue, through the activation of pertussis toxin-sensitive G proteins.

[Clinical study of operated nine thymic carcinomas]

Nine cases of thymic carcinoma (5 males and 4 females) were operated in our hospital between 1990 and 1998. These cases included 4 squamous cell carcinomas, 2 small cell carcinomas, 2 undifferentiated carcinomas and one adenocarcinoma. Preoperative chemotherapy were performed in 3 cases. All cases underwent median-sternotomy followed by mediastinal irradiation, 4 had total resection of the tumor, 2 had subtotal resection and 3 had exploratory thoracotomy followed by mediastinal irradiation. Adjuvant chemotherapy were administered in 4 cases and re-operation were performed in 2 cases. We applied Masaoka's clinical staging for thymoma, nine cases consisted of 6 stage III cases, 2 stage IV b cases and one stage IV a case. Within 2 years after operation, 3 cases (two complete resection cases and one exploratory thoracotomy case) were died of the carcinoma. However, two cases of squamous cell carcinoma have been alive more than 5 years after surgery followed by chemoradiation. The remaining 4 patients are alive either with or without the carcinoma after 7 to 28 months after operation. Thymic carcinoma is not so common mediastinal tumor but is expected to increase in the future. The treatment of thymic carcinoma remains a controversial matter and the survival is poor compared with invasive thymoma, but multimodal-therapy would contribute to improvement of the results in treatment for thymic carcinoma especially in squamous cell carcinoma.

Morbidity and mortality after 94 extrapleural pneumonectomies for empyema

BACKGROUND

Extrapleural pneumonectomy is still indicated in some patients with empyema. We examined morbidity and mortality after this high-risk operation.

METHODS

Between 1979 and 1998, 94 (92 chronic, 2 postsurgical) patients with empyema underwent extrapleural pneumonectomy. There were 79 men and 15 women (mean age, 59 years). Eighty-eight patients had a history of tuberculosis, and 53 had undergone a therapeutic pneumothorax. The right side was operated on in 50 patients and left in 44.

RESULTS

Operative mortality was 8.5%. Fifteen major complications (1 esophageal perforation, 9 empyemas, and 5 bronchopleural fistulas) occurred in 13 patients. Eight patients required reexploration for hemorrhage. Reexploration was a risk factor for empyema. Bronchopleural fistulas occurred only on the right side. Eighty-nine percent of the 86 operative survivors were free of empyemas at 5 years. Overall 5-year survival was 83%, and survival was better in patients without than in those with empyema.

CONCLUSIONS

Extrapleural pneumonectomy for empyema has acceptable morbidity and mortality. Postoperative empyema affects prognosis. Covering a bronchial stump with muscle is recommended, especially when the operation is performed on the right side.

[Assessment of the new TNM classification for resected lung cancer]

To evaluate the revised TNM classification, we investigated the prognoses of 552 consecutive patients who had resection of non-small-cell lung cancer between April 1982 and March 1996. According to the new classification, the 5-year survival rate was 76.9% for stage I A, 57.2% for stage I B (I A versus I B, p < 0.0005), 47.7% for stage IIA, 49.8% for stage IIB, 18.6% for stage IIIA (IIB versus IIIA, p = 0.005), 16.7% for stage IIIB, and 7.9% for stage IV (IIIB versus IV, p = 0.02). Especially for patients in stage I A, there was significant difference in survival between patients with the tumor size within 1.5 cm and those with larger than 1.5 cm. The survival rate for T3N0M0 patients was significantly better than that for T3N1-2M0, but there was no significant difference between patients with T3N0M0 disease and those with T2N1M0 disease. Concerning the pm1 patients, the survival rate was significantly better than other stage IIIB patients. Our results supported the revision for dividing stage I and putting T3N0M0 into stage IIB. However, the classification is controversial about dividing stage II and putting pm1 as T4 disease. Furthermore, subgrouping of T1N0M0 disease by tumor size, T3 by tumor invaded organ will be necessary in the next revisions.

Involvement of central opioid systems in human interferon-alpha induced immobility in the mouse forced swimming test

1. We investigated the mechanism by which human interferon-alpha (IFN-alpha) increases the immobility time in a forced swimming test, an animal model of depression. 2. Central administration of IFN-alpha (0.05 - 50 IU per mouse, i.cist.) increased the immobility time in the forced swimming test in mice in a dose-dependent manner. 3. Neither IFN-beta nor -gamma possessed any effect under the same experimental conditions. 4. Pre-treatment with an opioid receptor antagonist, naloxone (1 mg kg(-1), s.c.) inhibited the prolonged immobility time induced by IFN-alpha (60 KIU kg(-1), i.v. or 50 IU per mouse. i.cist. ). 5. Peripheral administration of naloxone methiodide (1 mg kg(-1), s. c.), which does not pass the blood - brain barrier, failed to block the effect of IFN-alpha, while intracisternal administration of naloxone methiodide (1 nmol per mouse) completely blocked. 6. The effect of IFN-alpha was inhibited by a mu(1)-specific opioid receptor antagonist, naloxonazine (35 mg kg(-1), s.c.) and a mu(1)/mu(2) receptor antagonist, beta-FNA (40 mg kg(-1), s.c.). A selective delta-opioid receptor antagonist, naltrindole (3 mg kg(-1), s.c.) and a kappa-opioid receptor antagonist, nor-binaltorphimine (20 mg kg(-1), s.c.), both failed to inhibit the increasing effect of IFN-alpha. 7. These results suggest that the activator of the central opioid receptors of the mu(1)-subtype might be related to the prolonged immobility time of IFN-alpha, but delta and kappa-opioid receptors most likely are not involved.

Characterization of histamine release induced by fluoroquinolone antibacterial agents in-vivo and in-vitro

Characterization of histamine release induced by fluoroquinolone antibacterial agents, levofloxacin and ciprofloxacin, was investigated in-vivo and in-vitro. Intravenous injection of levofloxacin and ciprofloxacin at 1-10 mg kg(-1) produced dose-related elevations in plasma histamine level in anaesthetized dogs. In contrast, levofloxacin was devoid of plasma histamine increment in anaesthetized rats at 100 mg kg(-1), whereas ciprofloxacin at the same dose caused endogenous histamine release. Levofloxacin and ciprofloxacin induced non-cytotoxic secretion of histamine from all mast cells tested in a concentration-dependent manner, whereas rat skin and peritoneal mast cells were thirty- to one-hundred-times less sensitive to the effect of fluoroquinolones as compared with the canine skin mast cells. These results suggest that the functional heterogeneity of mast cells from different species in histamine releasing activity of fluoroquinolones may exist, and that mast cells from the dog appear to be particularly sensitive to the effect of the fluoroquinolones.

[A case of far advanced breast cancer with distant metastases which had mostly disappeared after chemoendocrine therapy]

We report a case of far advanced breast cancer showing an excellent response to chemo-endocrine therapy. A 40-year-old female with a huge ulcerated tumor on her left anterior chest visited our hospital. Distant metastases were found in the lymph nodes, liver and bone. Therefore, endocrine therapy (toremifene and medroxyprogesterone acetate) and chemotherapy (cyclophosphamide, Therarubicin and 5-fluorouracil) were started as a combination treatment. As a result, the main tumor and metastatic lesion were remarkably reduced, and extended mastectomy with resection of right axillary lymph nodes was performed. Histologically, cancer cells in the primary lesion mostly disappeared, and only one lymph node in the left axillary lesion showed metastasis. No recurrence was found for 16 months after the surgical treatment. The combined therapy in the present case was extremely effective.

Mechanism of histamine release induced by levofloxacin, a fluoroquinolone antibacterial agent

The present study was designed to clarify the mechanism of histamine release caused by levofloxacin, a fluoroquinolone antibacterial agent, using rat peritoneal mast cells. Levofloxacin induced a concentration-dependent histamine secretion from 300 microg/ml without lactate dehydrogenase leakage, and the release was rapidly completed within 30 s. This action was dependent on temperature, energy, pH and intracellular Ca(2+), similarly to the effect of compound 48/80, a basic compound. Unlike that with the calcium ionophore A23187, histamine secretion due to levofloxacin or compound 48/80 was prevented by pretreatment with either pertussis toxin or benzalkonium chloride, a selective inhibitor of G proteins of G(i) subtypes. Moreover, the histamine release elicited by levofloxacin or compound 48/80 was suppressed by hydrolysis of sialic acid residues on the cell surface brought about by neuraminidase. These results demonstrate that the mechanism by which levofloxacin exerts histamine release may be closely linked to activation of pertussis toxin-sensitive G proteins.

Human interferon-alpha induces immobility in the mouse forced swimming test: involvement of the opioid system

In a previous study, we indicated that human interferon (IFN)-alpha (IFN-alpha, 6 x 10(4) IU/kg, i.v.), but not human IFN-beta or -gamma, prolonged the immobility time of the forced swimming test in mice. In this study, we investigated the mechanism of the effect of human IFN-alpha. None of the mouse IFNs tested (IFN-alpha/beta, IFN-beta, and IFN-gamma, 3 x 10(5) U/kg, i.v.) changed the immobility time or the spontaneous locomotor activity in mice. Indomethacin (10 mg/kg, s.c.), a cyclooxygenase inhibitor, did not affect the increase in the immobility time induced by human IFN-alpha (6 x 10(4) IU/kg, i.v.). However, naloxone (1 mg/kg, s.c.), an opioid receptor antagonist, blocked the increasing caused by human IFN-alpha in the forced swimming test. These results suggest that the increase in the immobility time caused by human IFN-alpha in the forced swimming test might be mediated through opioid receptors, but not mouse IFN receptors.

Human interferon-alpha increases immobility in the forced swimming test in rats

OBJECTIVES

We examined the immobility of the forced swimming test induced in an animal model by human interferon (IFN), which has often been reported to induce depression in clinical use.

METHODS

In the present study, we examined the effects of human IFNs on results of the forced swimming test in rats.

RESULTS

Single intravenous (IV) administration of human IFN-alpha (6x10(4) IU/kg), but not of human IFN-beta or -gamma, significantly increased immobility time in the forced swimming test in rats. Repeated administration of human IFN-alpha (6x10(3) IU/kg) also significantly increased the immobility time. On the other hand, none of the rat IFNs (rat IFN-alpha, -beta and -gamma, 6x10(4) IU/kg, IV) changed the immobility time. Neither human IFNs nor rat IFNs changed the locomotor activity of rats.

CONCLUSIONS

These findings suggest that human IFN-alpha has a greater potential for inducing increase of the immobility in the rat forced swimming test than human IFN-beta and -gamma, and that the effect of human IFN-alpha might not be mediated through IFN-alpha/beta receptors.

[Two cases of the bronchial cyst located in the anterior mediastinum]

Bronchial cysts are common cystic tumors around the tracheobronchial tree in the middle and posterior mediastinum and rarely locate in the anterior mediastinum. We reported two cases of the bronchial cyst located in the anterior mediastinum. One case was a 57 year-old-female. A thymic cyst was suspected and the extended total thymectomy was performed through the mediansternotomy. The microscopic examination showed bronchial epithelium and cartilage in the cystic wall. The another case was 71 year-old-male operated by thoracoscopic surgery for the cystic tumor in the anterior mediastinum. Microscopic examination showed bronchial epithelium and gland in the cystic wall.

[A case of thymic carcinoid with multiple endocrine neoplasm (MEN)-type I]

We presented a case of thymic carcinoid with MEN type I. A 43-year-old woman who followed at MEN type I for 4 years was pointed out an abnormal shadow by chest X-ray. Chest CT levealed the presence of two anterior mediastinal tumors. Extended total thymectomy was performed through the median sternotomy. There were 3 tumors in thymus. Histological examination revealed three tumors in the thymus and all of the tumor were diagnosed carcinoid. Our experience suggests that CT or MRI of the chest should be considered as part of clinical screening in patients with MEN type I.

[An evaluation of pathologic T3 lung cancer]

A total of 35 pT3 patients of lung cancer underwent pulmonary resection from 1983 to 1997 in our department. The overall five-year survival rate of the 35 cases was 35.8%. There was no significant difference between the five-year survival rate of squamous cell carcinoma and that of adenocarcinoma. A superior outcome was observed for cases of curative resection compared with that of non-curative resection. Five-year survival rates of 19 patients with N0 disease, 16 patients with N1 or N2 disease were 46.6% and 22.2% respectively (p < 0.05). There was no significant differences among the survival rates according to the site of tumor invasion. We concluded that the long-term survival of patients with pathologic T3 disease critically depended on the lymph node state and completeness of resection.

Inhibition of intestinal microflora beta-glucuronidase modifies the distribution of the active metabolite of the antitumor agent, irinotecan hydrochloride (CPT-11) in rats

PURPOSE

SN-38, a metabolite of irinotecan hydrochloride (CPT-11), is considered to play a key role in the development of diarrhea as well as in the antitumor activity of CPT-11. We have previously found that the inhibition of beta-glucuronidase, which hydrolyzes detoxified SN-38 (SN-38 glucuronide) to reform SN-38, in the lumen by eliminating the intestinal microflora with antibiotics, markedly ameliorates the intestinal toxicity of CPT-11 in rats. In this study we compared the disposition of CPT-11 and its metabolites in rats treated with and without antibiotics.

METHODS

Rats were given drinking water containing 1 mg/ml penicillin and 2 mg/ml streptomycin from 5 days before the administration of CPT-11 (60 mg/kg i.v.) and throughout the experiment. CPT-11, SN-38 glucuronide and SN-38 concentrations in the blood, intestinal tissues and intestinal luminal contents were determined by HPLC.

RESULTS

Antibiotics had little or no effect on the pharmacokinetics of CPT-11, SN-38 glucuronide or SN-38 in the blood, or in the tissues or contents of the small intestine, which has less beta-glucuronidase activity in its luminal contents. In contrast, antibiotics markedly reduced the AUC1-24 h of SN-38 (by about 85%) in the large intestine tissue without changing that of CPT-11, and this was accompanied by a complete inhibition of the deconjugation of SN-38 glucuronide in the luminal contents.

CONCLUSIONS

These results suggest that SN-38, which results from the hydrolysis of SN-38 glucuronide by beta-glucuronidase in the intestinal microflora, contributes considerably to the distribution of SN-38 in the large intestine tissue, and that inhibition of the beta-glucuronidase activity by antibiotics results in decreased accumulation of SN-38 in the large intestine.

Enhancement of immobility in mouse forced swimming test by treatment with human interferon

We investigated the depression induced by human interferons using the forced swimming test in mice. Intravenous (i.v.) administration of interferon-alpha s (natural interferon-alpha, recombinant interferon-alpha-2a and recombinant interferon-alpha-2b, 600-60000 IU/kg) increased the immobility time in the forced swimming test in a dose-dependent manner, but natural interferon-beta and recombinant interferon-gamma-1a did not affect the immobility time. The increase in the immobility time induced by recombinant interferon-alpha-2b peaked at 15 min after dosing. Administration of recombinant interferon-alpha-2b (6000 IU/kg, i.v.) once daily for 7 consecutive days increased the immobility time, but natural interferon-beta and recombinant interferon-gamma-la did not. Recombinant interferon-alpha-2b in combination with the anti-depressants imipramine (10 mg/kg, i.p.) and mianserin (20 mg/kg, i.p.) did not increase the immobility time. These results suggest that interferon-alpha has a greater potential for inducing depression than interferon-beta and -gamma, and that anti-depressants are effective against interferon-alpha-induced depression.

Involvement of beta-glucuronidase in intestinal microflora in the intestinal toxicity of the antitumor camptothecin derivative irinotecan hydrochloride (CPT-11) in rats

Irinotecan hydrochloride (CPT-11), an antitumor camptothecin derivative, causes severe forms of diarrhea clinically. We characterized CPT-11-induced diarrhea histologically and enzymologically and assessed the relationships between intestinal toxicity and the activity of the enzymes that play a key role in the major metabolic pathway of CPT-11 in rats. CPT-11 (60 mg/kg i.v. for 4 days) induced intestinal toxicity characterized by severe chronic diarrhea, loss of body weight, and anorexia. Histological damage was most severe in the cecum. The segmental difference in the degree of the damage showed good correlation with the beta-glucuronidase activity in the contents of the lumen in each case, but not with the intestinal tissue carboxylesterase activity, which converts CPT-11 to its active form (7-ethyl-10-hydroxycamptothecin). Inhibition of the beta-glucuronidase activity in the intestinal microflora by antibiotics (1 mg penicillin and 2 mg streptomycin per ml of drinking water) markedly ameliorated the diarrhea and reduced cecal damage. Analysis of CPT-11 and its metabolites in the feces indicated that antibiotics completely inhibited the deconjugation of the glucuronic conjugate of 7-ethyl-10-hydroxycamptothecin by beta-glucuronidase. It is suggested that CPT-11-induced diarrhea would be attributable to the damage to the cecum, and that the inhibition of the beta-glucuronidase activity in the intestinal microflora is a major protective effect of antibiotics.

Increasing-current electroshock seizure test: a new method for assessment of anti- and pro-convulsant activities of drugs in mice

We developed the increasing-current electroshock seizure (ICES) test, a new method for assessment of anti- and pro-convulsant activities of drugs in mice. In this method, a single train of pulses (square wave, 5 msec, 20 Hz) of linearly increasing intensity from 5 to 30 mA (increment of 0.1 mA/0.1 sec, i.e., 5-30 mA in 25 sec) was applied via ear electrodes. The current at which tonic hindlimb extension occurred was recorded as the seizure threshold. Thus, this method allows determination of the seizure threshold current for individual animals. Carbamazepine, phenytoin, valproate, phenobarbital, diazepam, and morphine all increased the seizure threshold current in a dose-dependent manner, whereas ethosuximide was not effective. The seizure threshold current decreased after treatment with reserpine, chlorpromazine, aminophylline, strychnine, pentylenetetrazol, bicuculline, picrotoxin, and ethyl-beta-carboline-3-carboxylate (beta-CCE). These results indicate that the ICES test, like the maximal electroshock seizure test, is a model of grand mal-type seizure and is useful for evaluation of both the anti- and pro-convulsant activities of drugs.

[General pharmacological study of iodixanol, a new non-ionic isotonic contrast medium]

The general pharmacological study of iodixanol, a non-ionic isotonic contrast medium, was conducted. 1) Iodixanol administered intravenously over a dose range of 320 to 3,200 mgI/kg had little or no effect on the general behavior, spontaneous locomotor activity, hexobarbital sleeping time, pain response, electroshock- or pentylenetetrazol-induced convulsion (mouse), EEG or body temperature (rabbit), gastrointestinal propulsion (mouse) or skeletal muscle contraction (rabbit). Iodixanol had no specific interaction with acetylcholine, histamine, serotonin, nicotin, BaCl2 (ileum), methacholine (trachea), isoprenaline (atrium) or oxytocin (pregnant uterus), nor had any effect on spontaneous contractility (atrium and uterus), or transmural electrostimulation-induced contractility (vas deferens) at concentrations of < or = 3.2 x 10(-3) gI/ml in vitro. Iodixanol had no effect on the cardiovascular system of dog, except that it increased femoral blood flow and respiratory rate at doses of > or = 1,000 mgI/kg. Iodixanol at 3,200 mgI/kg i.v. reduced urine output with a decrease in Na+ and Cl- excretion, whereas at 320 mgI/kg i.v., it slightly increased urine output (rat). 2) Injections of iodixanol into the cerebroventricular (0.96, 9.6 mgI/mouse and 3.2, 32 mgI/rat), left ventricular (1,920, 6,400 mgI/dog) or coronary artery (640, 1,920 mgI/dog) had no conspicuous effect on the central nervous system or the cardiovascular system, respectively. There was no marked difference among iodixanol, iohexol and iopamidol in this respect. Vascular pain during injection into the femoral artery (300-320 mgI/guinea pig) appeared to be less intense with iodixanol, compared with the other contrast media iohexol and iopamidol. These results suggest that intravenous injection of iodixanol is relatively free from pharmacological activity, and effects of iodixanol on the central nervous system (intracerebroventricular injection) and cardiovascular system (intra-left ventricular and -coronary injections) are comparable to those of iohexol and iopamidol. Furthermore, intra-femoral injection of iodixanol has less of a tendency to produce vascular pain than those of iohexol and iopamidol.

Protective effects of kampo medicines and baicalin against intestinal toxicity of a new anticancer camptothecin derivative, irinotecan hydrochloride (CPT-11), in rats

In clinical use, irinotecan hydrochloride (CPT-11; 7-ethyl-10-[4-(piperidino)-1-piperidino]carbonyloxycamptothecin), a novel antitumor agent, causes a relatively high incidence of severe forms of diarrhea. We investigated whether baicalin, an inhibitor of beta-glucuronidase, which deconjugates the glucuronide of the active metabolite of CPT-11, SN-38 (7-ethyl-10-hydorxycamptothecin), and Japanese herbal medicines (Kampo medicines) which contain baicalin can ameliorate CPT-11-induced intestinal toxicity in rats. CPT-11 (60 mg/kg i.v. once daily for 4 consecutive days) induced intestinal toxicity characterized by diarrhea, loss of body weight, anorexia and disruption of intestinal epithelium. Treatment with baicalin (25 mg/kg p.o. twice daily) or Kampo medicines (TJ-14 and TJ-114; 1 g/kg p.o. twice daily) from the day before to 4 or 10 days after the start of CPT-11 administration resulted in significantly decreased weight loss, improved anorexia and delayed onset of diarrheal symptoms. Histological examination revealed that Kampo medicine-treated animals had less damage to the intestinal epithelium and that damage was repaired more rapidly than in control rats. These results suggest that the prophylactic use of Kampo medicines (TJ-14 and TJ-114) may be of value against CPT-11-induced intestinal toxicity.

[Study on the mechanisms of diarrhea induced by a new anticancer camptothecin derivative, irinotecan hydrochloride (CPT-11), in rats]

We investigated the mechanisms of CPT-11-induced diarrhea. 1) CPT-11 (80 mg/kg, i.v.) induced watery diarrhea within 1 hr after dosing in saline-loaded (10 ml/kg, p.o.) rats. This was partially inhibited by subcutaneous injection of atropine (1 mg/kg) or ondansetron (1 mg/kg) and almost completely inhibited by a combination of atropine and ondansetron or by clonidine (0.3 mg/kg) or morphine (10 mg/kg) alone. 2) CPT-11 at the same dose reduced intestinal fluid absorption, which was blocked by the anti-diarrheal agents mentioned above. Intraluminal injection of CPT-11 (20 mg/2 ml) inhibited fluid absorption and induced fluid secretion. 3) CPT-11, 60 mg/kg, by single intravenous injection induced fewer enzymological and histological changes in the small intestine than 5-FU at 270 mg/kg, while 4 consecutive dosings of CPT-11 induced delayed diarrhea (days 5-7) associated with disruption of intestinal integrity. Co-administration with anti-diarrheal agents, except for ondansetron, protected against watery diarrhea appearing within 1 hr after CPT-11 on days 3 and 4, but worsened delayed diarrhea. These results suggest that single injection of higher doses of CPT-11 causes watery diarrhea at an acute phase at least partly by reducing fluid absorption or increasing secretion, and that while conventional anti-diarrheal agents protect against watery diarrhea, their co-administration in repeated CPT-11 administration has no ameliorative effect on CPT-11-induced delayed diarrhea.

General pharmacological profile of the new cognition-enhancing agent nefiracetam

The general pharmacological properties of a novel cognition-enhancing agent, nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide, DM-9384, CAS 77191-36-7) were investigated, and the following results were obtained. 1. Central nervous system: Nefiracetam showed depressant activities (such as ataxia) on general behavior (mice), and inhibited spontaneous locomotor activity, rota-rod and traction performances (mice) and polysynaptic potential of the spinal reflex (rats), and potentiated pentobarbital anesthesia (mice). The drug inhibited electroshock-induced seizure at relatively low doses, but did not affect chemoshock-induced seizure (mice). Nefiracetam failed to show analgesic activity in the tail pinch test, but inhibited the acetic acid-induced writhing syndrome (mice). An inhibitory pattern in the electroencephalogram was observed (cats). Nefiracetam had little or no effect on body temperature (rats). 2. Respiratory and cardiovascular systems: Nefiracetam induced transient decreases in blood pressure, left ventricular pressure and LV dp/dt max at higher doses (dogs). 3. Autonomic nervous system: Nefiracetam had no influence on pupil size (rabbits). The drug induced no significant effect on the pressor response to norepinephrine or depressor response to acetylcholine, but inhibited the contractile response of the nictitating membrane to preganglionic cervical sympathetic nerve stimulation at the highest dose (dogs). 4. Gastrointestinal system: Nefiracetam inhibited gastrointestinal propulsion (mice), gastric emptying rate and gastric secretion (rats) at higher doses. Nefiracetam produced no apparent damage in the gastric mucosa, and had no effect on bile secretion (rats). 5. Isolated smooth muscle: Nefiracetam had no effect on the resting tonus of isolated ileum, whereas it inhibited the contractile response to acetylcholine, histamine, serotonin, nicotine and BaCl2 at higher concentrations (guinea pigs). Nefiracetam had no effect on the resting tonus or the serotonin-induced contraction of stomach fundus (rats). The drug had no effect on the resting tonus or the norepinephrine-induced contraction of vas deferens, but tended to inhibit the contraction induced by nerve stimulation (guinea pigs). Nefiracetam had little or no effect on the resting tonus or oxytocin-induced contraction of virgin uterus, or on spontaneous contraction of pregnant uterus (rats). Nefiracetam did not affect the resting tonus of trachea, whereas it inhibited isoproterenol-induced relaxation at the highest concentration (guinea pigs). Nefiracetam had no chronotropic effect in isolated atria, but showed a slight negative inotropic effect at the highest concentration (guinea pigs). 6. Miscellaneous: Nefiracetam slightly decreased urinary volume, whereas it did not affect urinary electrolyte excretion (rats).(ABSTRACT TRUNCATED AT 400 WORDS)

Cardiovascular properties of the new anti-ulcer drug 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl]methyl]-amino-N- methylbenzamide

Cardiovascular activities of 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl]methyl]-amino-N- methylbenzamide (DQ-2511, CAS 104775-36-2), an anti-ulcer drug, were investigated in anesthetized dogs and conscious rats. In anesthetized and laparotomized dogs, DQ-2511 at intravenous doses of 5-50 mg/kg dose-relatedly induced an increase in celiac and mesenteric arterial blood flow, and a decrease in their resistance, whereas the drug had little or no effect on carotid and renal blood flow. DQ-2511 increased cardiac contractility in anesthetized dogs at an intravenous dose of 15 mg/kg. In addition to this effect, it produced an increase in respiratory rate, a decrease in blood pressure and a slight increase in heart rate after dosing at 50 mg/kg. The drug had little or no effect on femoral blood flow and produced no significant changes in the electrocardiogram. In conscious rats, blood flow in gastrointestinal organs was compared with flow in other organs using the microsphere method. Blood flow in the stomach, duodenum, ileum, pancreas, spleen, and kidney tended to decrease in the vehicle-treated control group. DQ-2511, at an oral dose of 100 mg/kg, significantly increased blood flow in the stomach, duodenum and spleen, and tended to increase flow in the pancreas, testis and fat in comparison with the vehicle-treated control group. Blood flow in the liver, heart and skeletal muscle tended to decrease, whereas the other regional blood flows did not differ from those in the control group. DQ-2511 at this oral dose had little or no effect on blood pressure, heart rate, cardiac output and total peripheral resistance in rats.(ABSTRACT TRUNCATED AT 250 WORDS)

General pharmacological profile of the new anti-ulcer drug 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl]methyl]-amino-N -methylbenzamide

Pharmacological properties of the anti-ulcer drug 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl] methyl]-amino-N-methylbenzamide (DQ-2511, CAS 104775-36-2) on the central and autonomic nervous systems, smooth muscle, gastrointestinal system, and other miscellaneous systems were investigated. 1. DQ-2511 showed little or no influence on general behavior, spontaneous motor activity, hexobarbital sleeping time (mouse), conditioned avoidance response (rat), body temperature (rabbit), EEG or spinal reflex (cat) after oral administration (300-1000 mg/kg) or intravenous injection (15, 50 mg/kg). It also had no anticonvulsant or analgesic activities (mouse). 2. DQ-2511 had no influence on pupil size (rabbit). It reduced or tended to reduce contractile responses of the nictitating membrane induced by electrical stimulation of pre- and post-ganglionic sympathetic nerve (cat) at the highest dose. The drug inhibited the pressor response to norepinephrine, but had little or no inhibitory effect on the depressor response to acetylcholine at the highest dose (dog). 3. DQ-2511 reduced contractile responses to nicotine, BaCl2, acetylcholine, histamine and serotonin (isolated guinea pig ileum), to acetylcholine and histamine (trachea), and to norepinephrine (vas deferens) at high concentrations. It also inhibited spontaneous and oxytocin-induced motility (isolated rat uterus). 4. DQ-2511 decreased gastric motility in a dose-related manner at intravenous doses of 5-50 mg/kg (dog). It also reduced gastric emptying rate at oral doses of 100-1000 mg/kg, and gastric secretion at intraperitoneal doses of 100-300 mg/kg (rat). On the other hand, it induced no definite changes in intestinal motility (dog) or gastrointestinal transit (mouse).(ABSTRACT TRUNCATED AT 250 WORDS)

[Central effects of iohexol and iopamidol, non-ionic contrast media]

Central effects of intravenously (i.v.)-administered iohexol were compared with those of iopamidol in a series of tests. Mannitol was used as a reference. As assayed by the primary screening test based on Irwin's method, i.v. administration of mannitol resulted in a score of 0 in ddY mice and a score of 0.6 in ICR mice in the startle response. These results were not different from the data of both iohexol and iopamidol. Iopamidol at a dose of 1750 mgI/kg produced an inhibitory effect on the spontaneous locomotor activity. Iohexol at a dose of 7000 mgI/kg potentiated the duration of thiopental-induced narcosis. Hypothermia was caused by high doses of both iohexol and iopamidol. Electric stimulus increased the mortality of mice pretreated with high doses of iohexol and iopamidol. Both drugs had no notable activities in the anticonvulsant, electroencephalic, muscle relaxant and antinociceptive tests. These results indicate that both iohexol and iopamidol do not necessarily possess a similar pharmacological action. Judging from the LD50 of approximately 15000 mgI/kg for both drugs, they seem unlikely to have a specific pharmacological action on the central nervous system.

Pharmacological studies with the alpha 2-adrenoceptor antagonist midaglizole. Part II: Central and peripheral nervous systems

Pharmacological properties of midaglizole (DG-5128, CAS 66529-17-7) on central and peripheral nervous systems were investigated in comparison with those of tolbutamide. 1. Central nervous system: Midaglizole showed little or no effects on general behavior (mouse), spontaneous motor activity (mouse), hexobarbital anesthesia (mouse), conditioned avoidance response (rat) and body temperature (rabbit) at an oral dose of 100 mg/kg. It also produced little or no changes in electroencephalogram (cat) and spinal reflex (cat) after intravenous dosing of 10 mg/kg. The drug lacked anticonvulsant and analgesic activities (mouse). Midaglizole produced clonic convulsion, mydriasis, lacrimation, increase in pinna reflex, decrease in spontaneous motor activity, increase in pain threshold (mouse) and rise in body temperature (rabbit) at oral dose of 300 mg/kg. Tolbutamide showed similar effects except that it potentiated hexobarbital anesthesia, slightly decreased convulsion and tended to decrease body temperature. 2. Autonomic nervous system: Midaglizole potentiated the pressor response to norepinephrine and inhibited the depressor response to acetylcholine at an intravenous dose of 10 mg/kg (anesthetized dogs). Similar results were observed after dosing of tolbutamide. Midaglizole potentiated the contractile response of nictitating membrane to pre- and post-ganglionic cervical sympathetic nerve stimulation after intravenous dosing of 1 mg/kg (cat). Tolbutamide lacked the activity on the contraction elicited by both stimulations. Midaglizole and tolbutamide had little or no effect on pupil size (rabbit). 3. Skeletal muscle contraction (neuromuscular junction): Midaglizole (3-10 mg/kg i.v.) slightly potentiated the tibialis anterior muscle contraction induced by peroneal nerve stimulation, but did not potentiate the contraction by direct (muscle) stimulation (rabbit). On the other hand, tolbutamide increased the contraction induced by both nerve and muscle stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological studies with the alpha 2-adrenoceptor antagonist midaglizole. Part III: Smooth muscle, gastrointestinal and miscellaneous systems

Pharmacological properties of midaglizole (DG-5128, CAS 66529-17-7) on smooth muscle, gastrointestinal and miscellaneous systems were investigated in comparison with those of tolbutamide. 1. Isolated smooth muscle: Midaglizole inhibited the contractile responses of the ileum to nicotine, acetylcholine, serotonin and BaCl2, and especially the response to histamine (guinea pig). Tolbutamide also reduced the contractions. On spontaneous motility of the uterus (estrus, diestrus, pregnant), midaglizole produced an increase in tonus and frequency, and decrease in contractile amplitude (rat). Tolbutamide reduced the motility of the uterus. The contractile response of the vas deferens to norepinephrine was potentiated after midaglizole and tolbutamide (guinea pig). Midaglizole inhibited the contractile response of the trachea to histamine, whereas it had little or no effect on the response to acetylcholine (guinea pig). Tolbutamide reduced the responses to both spasmogens. 2. Gastrointestinal system: Midaglizole induced an increase in gastrointestinal transit (mouse) and potentiated the gastrointestinal motility (dog). Tolbutamide was without any effect on these parameters. Gastric emptying rate, gastric secretion and gastric mucosa were not influenced after midaglizole (rat). Tolbutamide decreased gastric secretion and produced injury of gastric mucosa. 3. Urine volume: Midaglizole and tolbutamide showed a diuretic activity (rat). 4. Anti-inflammatory activity: Midaglizole and tolbutamide inhibited carrageenin-induced paw edema (rat).

Pharmacological studies with the alpha 2-adrenoceptor antagonist midaglizole. Part I: Respiratory and cardiovascular systems

Respiratory and cardiovascular effects of midaglizole (DG-5128, CAS 66529-17-7) were investigated in comparison with yohimbine, idazoxan and tolbutamide. 1. Respiration: Midaglizole had little or no effect on respiration of anesthetized dogs. Yohimbine and idazoxan augmented respiration at low dose. Tolbutamide depressed respiratory rate and depth at high dose. 2. Blood pressure and heart rate: Midaglizole produced dose-related hypotension and bradycardia in anesthetized dogs which had laparotomy, whereas it had little or no effect on blood pressure and heart rate of dogs which had no laparotomy (unlaparotomized dogs). Tendency of slight hypertension was observed after high dose of tolbutamide in laparotomized dogs, and transient hypotension was induced in unlaparotomized dogs. Yohimbine and idazoxan increased blood pressure at low dose in unlaparotomized dogs. In laparotomized dogs, yohimbine produced hypertension and hypotension at low and high doses, respectively. In isolated guinea pig atria, midaglizole produced bradycardia which was not observed after yohimbine. Tolbutamide decreased the pulse rate at high concentration. 3. Cardiac contractility: Midaglizole produced increase in cardiac contractility of anesthetized dogs. Yohimbine and idazoxan, at low dose, showed similar inotropic activity. Prazosin also produced a positive inotropic effect, whereas tolbutamide lacked the activity. The inotropic effects of midaglizole and yohimbine were antagonized by pretreatment with propranolol or hexamethonium, whereas a similar effect of prazosin was not influenced by both blockers. In isolated guinea pig atria, midaglizole showed slight inotropic activity. Yohimbine was without any effect, whereas tolbutamide reduced the contractile force. 4. Femoral blood flow: Midaglizole produced a transient increase in femoral blood flow and a decrease in femoral arterial resistance of anesthetized dogs. Yohimbine and idazoxan, at low dose, showed similar vasodilator activity. Prazosin also produced a vasodilator effect, whereas tolbutamide lacked the activity. The vasodilator effects of midaglizole and yohimbine were not affected with propranolol, but inhibited after hexamethonium. 5. Mesenteric blood flow: Midaglizole significantly decreased mesenteric blood flow and increased the arterial resistance of anesthetized dogs in a dose dependent manner. Tolbutamide induced a decrease in blood flow and an increase in arterial resistance only at the highest dose used. Yohimbine increased mesenteric blood flow at low dose and decreased it at high dose. 6. Renal blood flow: Midaglizole dose-relatedly decreased renal blood flow of anesthetized dogs. Tolbutamide and yohimbine at high dose produced a long-lasting decrease of the blood flow. Midaglizole produced a slight transient reduction of renal arterial resistance which was followed by a slight increase. Tolbutamide increased the arterial resistance at high dose.(ABSTRACT TRUNCATED AT 400 WORDS)

General pharmacological profiles of the new beta-adrenoceptor antagonist carvedilol

General pharmacological properties of carvedilol (BM 14.190) were investigated in comparison with propranolol. 1. Central nervous system: Carvedilol caused reduction of awareness, motor activity and muscle tone, and staggering gait in Irwin's test (mice). It decreased spontaneous motor activity and potentiated hexobarbital anesthesia (mice). It lacked anticonvulsant activity (mice) and did not have any effect on body temperature (rabbits). Various changes were produced in mono- and polysynaptic spinal reflex (cats). In EEG, a slight arousal pattern was observed (cats). These effects of carvedilol were weaker than those observed after propranolol administration in general. Carvedilol, however, caused potentiation of hexobarbital anesthesia at lower doses than propranolol. Carvedilol inhibited acetic acid-induced writhing syndrome, whereas it failed to show analgesic activity in the tail-pinch test (mice). Propranolol inhibited both pain reactions. 2. Respiratory and cardiovascular system (dogs): Carvedilol increased respiratory rate and decreased expiratory velocity. It produced hypotension and bradycardia. Cardiac contractility was reduced and femoral blood flow was transiently increased after carvedilol administration. Propranolol induced weaker hypotension and greater bradycardia in comparison with carvedilol. It decreased femoral blood flow. 3. Autonomic nervous system: Carvedilol had little or no effects on pupil size, whereas propranolol produced mydriasis (rabbits). Carvedilol inhibited pressor response to norepinephrine (rats), and it also reduced the nictitating membrane contraction induced by pre- and postganglionic sympathetic nerve stimulation (cats). Propranolol did not show any inhibitory effect on pressor response to norepinephrine and on the contractile response induced by preganglionic sympathetic nerve stimulation. 4. Smooth muscle: Carvedilol produced inhibitory effects on spontaneous motility, and contractile responses to acetylcholine, histamine, nicotine, serotonin and BaCl2 in isolated ileum (guinea pigs). It also inhibited contractile responses to acetylcholine and histamine in isolated trachea (guinea pigs), and spontaneous motility in isolated uterus (rats). Carvedilol reduced norepinephrine-induced contraction of isolated vas deferens at lower concentration (guinea pigs). 5. Digestive system: Decrease in intestinal motility was observed after intravenous administration of carvedilol and propranolol (rabbits). However, carvedilol failed to influence on gastric motility and tonus, whereas propranolol increased them (rabbits). Carvedilol, like propranolol, induced little or no effects on gastro-intestinal transit (mice) and gastric emptying rate (rats). Both drugs decreased gastric secretion at similar dose (rats). Carvedilol at higher doses produced lesion of gastric mucosa, whereas propranolol did not show these effects (rats). 6. Skeletal muscle: In in vitro experiment, carvedilol, like propranolol, reduced the contractile response of diaphragm to nerve and muscle stimulation (rats)...

General pharmacological properties of muroctasin

General pharmacological effects of N2-[(N-acetyl-muramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-ly sine MDP-Lys(L18), muroctasin) were examined and the following results were obtained. 1. Central nervous system: MDP-Lys(L18) had no effect on behavior, spontaneous motor activity, electroshock- and chemoshock-induced convulsions, hexobarbital sleeping time, pain threshold (mice), conditioned avoidance response (rats) at a dose of 0.4 mg/kg, s.c. and EEG as well as spinal reflex (cats) at a dose of 0.4 mg/kg, i.v. It produced a significant elevation in body temperature (rabbits) at doses of 13 micrograms/kg, s.c. and greater. 2. Respiratory and cardiovascular system (dogs): MDP-Lys(L18) did not show any significant effect on respiratory and cardiovascular functions at a dose of 0.4 mg/kg i.v. 3. Autonomic nervous system: MDP-Lys(L18) induced a miosis (rabbits) at doses of 13 micrograms/kg s.c. and greater. It did not affect norepinephrine-induced pressor and acetylcholine-induced depressor responses (dogs) and contraction of the nictitating membrane induced by electrical stimulation (cats) at a dose of 0.4 mg/kg i.v. 4. Smooth muscles: In the experiments using the isolated ileum, vas deferens, trachea (guinea pigs) and uterus (rats), MDP-Lys(L18) showed neither spasmogenic nor spasmolytic activity at a concentration of 4 x 10(-6) g/ml. Gastrointestinal propulsion (mice), gastric mucosa, gastric emptying rate and gastric secretion (rats) were not affected by this drug at a dose of 0.4 mg/kg s.c. MDP-Lys(L18) did not influence gastrointestinal motility (dogs) at a dose of 0.4 mg/kg, i.v. 5. Miscellaneous: MDP(L-18) suppressed carrageenan-induced edema (rats) at doses of 0.13 mg/kg s.c. and greater.(ABSTRACT TRUNCATED AT 250 WORDS)