Synthesis and structure--activity relationships of fused imidazopyridines: a new series of benzodiazepine receptor ligands

2-Arylimidazo[4,5-c]quinolines and analogous fused imidazopyridines were synthesized and evaluated as benzodiazepine receptor ligands. Affinity to the receptors was greatly affected by the bulkiness of the aryl group at the 2-position, compared to the pyrazoloquinolines such as CGS-9896. Derivatives with an isoxazole moiety at the 2-position showed high binding affinity and in vivo activity. In the imidazo[4,5-c]quinoline series, substitution at the 6-position decreased or abolished activity. Most derivatives with an unsubstituted isoxazolyl group showed antagonist or inverse agonist activity except for the 7-halo analogues, which exhibited agonist activity. On the other hand, 5-methylisoxazol-3-yl or 3-methylisoxazol-5-yl derivatives generally exhibited agonist activity. A similar substitution effect on the isoxazole moiety was observed in the imidazopyridines fused with a nonaromatic ring. From the detailed pharmacological evaluation, S-8510, 2-(3-isoxazolyl)-3,6,7,9-tetrahydroimidazo[4,5-d]pyrano++ +[4,3-b]pyridine monophosphate, possessing weak inverse agonist activity was selected as a therapeutic candidate for the treatment of some symptoms of senile dementia.

Effects of pancreatic duct ligation and aging on acute taurocholate-induced pancreatitis. Experiments in the perfused pancreas in rats

CONCLUSION

When taurocholate was injected into the common bile duct, high ductal pressure due to ligation of the pancreatic duct did not produce more damage in the pancreas of both old rats and young adult rats, and levels of pancreatic enzymes in portal venous effluent were lower in old rats than in younger rats.

BACKGROUND

The effects of ligation of the pancreatic duct and aging on acute pancreatitis caused by taurocholate are still unclear.

METHODS

Young adult and old male Wistar rats were used. Six hours after ligation of the common bile duct in both the duodenum and liver hilus, rats were killed and the pancreata were perfused. Taurocholate or normal saline was injected retrogradely into the common bile duct. The levels of amylase and lipase in the portal venous effluent were determined as markers of damage to the pancreas. The pancreas was also histologically examined after the perfusion experiments using an Image Analysis System.

RESULTS

(1) A nonsignificant elevation of pancreatic enzymes was found in portal venous effluent by the retrograde injection of saline into the common bile duct. Injection of taurocholate caused a marked elevation of enzymes in the effluent for the first 30 min after injection, which then gradually decreased. (2) Basal levels of pancreatic enzymes were significantly higher in the ligation group than in the nonligation group. Injection of saline into the common bile duct had no apparent effect on enzymes in the effluent. In contrast, taurocholate injection into the common bile duct produced a marked increase in enzymes in the portal venous effluent. However, no significant difference was found between the ligation group and the nonligation group. (3) Similar findings were obtained when old rats were used. (4) Although basal levels of enzymes were almost the same in nonligated old and young adults rats, taurocholate injection into the pancreatic duct in old rats resulted in a significant depression of enzymes compared to that in young adult rats. In the ligation group, pancreatic enzymes in the portal venous effluent following taurocholate injection tended to be lower in old rats than in young adult rats. The results were histologically supported in that various degrees of fibrosis were found in the pancreata of old rats.

[Induction chemotherapy followed by adjuvant surgery (IC-AS) in patients with stage I-II small cell lung cancer (SCLC)]

Ten patients with stage I-II SCLC received IC-AS between 1984 and 1993. As induction chemotherapy, COMP-VAN alternating chemotherapy and CAV-PVP hybrid chemotherapy were administered. The former consisted of a 4-drug combination of cyclophosphamide (CPA), vincristine (VCR), methotrexate (MTX) and procarbazine alternated with a 3-drug combination of etoposide (ETP), adriamycin (ADM) and nimustine every 4 weeks. In the latter, a 3-drug combination of CPA, ADM and VCR given on day 1, and a 2-drug combination of ETP and cisplatin on day 8, were repeated every 4 weeks. All the patients had an objective response, including one complete response by induction chemotherapy. Post-operative pathology revealed SCLC in 4 patients, adenocarcinoma in 2 and no tumor (pathological CR) in 4. Four patients relapsed, and a intrathoracic relapse was experienced in only 2 patients. Six patients have died: 3 from relapsing SCLC, 2 from stomach cancer, and 1 from squamous lung cancer, who was salvaged from relapsing SCLC. The median survival time was 27.5 months, and the 3-year survival rate 37.5%. These results indicate that IC-AS is highly effective for stage I-II SCLC and warrant additional studies comparing IC-AS with chemo-radiotherapy.

[Transient promyelocytic expansion in primary myelofibrosis]

A 46-year-old man with primary myelofibrosis developed polyarthralgia. Marked hepatosplenomegaly was noted, and hematological examinations revealed a white cell count of 25,600/microliters with 42% promyelocytes and thrombocytopenia. The promyelocytes were positive for CD4 antigen and nonspecific esterase as well as peroxidase. Cytogenetic analysis of circulating mononuclear cells showed the trisomy of No. 22 chromosome in 3 of 5 cells examined. Four months later, the patient became asymptomatic, and hematological picture and hepatosplenomegaly returned to the original level. This is the first report describing the transient promyelocytic expansion in myeloproliferative disorders.

[Neoplastic angioendotheliosis diagnosed by open lung biopsy]

Neoplastic angioendotheliosis (NAE) is a rare neoplastic disease, and its pre-mortem diagnosis is extremely difficult. A 49-year-old male developed vertigo, hearing and visual disturbance, transverse myelopathy below Th 5 and hypercalcemia. These symptoms were markedly improved by VEPA chemotherapy. Thirty-four months after onset, diffuse reticular shadows were noted on chest X-ray. The biopsy specimen of the lung revealed intravascular lymphoid cells differentially stained with L26 and LCA. Southern blot analysis of the DNA from the tissue showed rearranged bands for the immunoglobulin gene (JH). A diagnosis of NAE of B-cell nature was established.

Behavioral and electroencephalographic properties of duloxetine (LY248686), a reuptake inhibitor of norepinephrine and serotonin, in mice and rats

Duloxetine is a dual inhibitor of norepinephrine and serotonin reuptake. Duloxetine (3.13-50 mg/kg p.o.) significantly prevented tetrabenazine (1 and 50 mg/kg s.c.)-induced ptosis in mice and rats. Moreover, duloxetine (1.56-12.5 mg/kg p.o.) also inhibited reserpine (1 mg/kg s.c.)-induced hypothermia in mice. When duloxetine (12.5-100 mg/kg p.o.) and 5-hydroxytryptophan (80 and 100 mg/kg i.p.), a precursor of serotonin, were administered simultaneously to mice and rats, head movement behavior and tremor were observed. In addition, duloxetine (25-100 mg/kg p.o.) significantly attenuated immobility in forced swimming in mice, as equally effective as commonly used antidepressant drugs. Duloxetine (12.5-25 mg/kg p.o.) significantly decreased rapid eye movement sleep and slow-wave deep sleep and increased the awake period, as shown in the rat EEG. However, duloxetine (25-200 mg/kg p.o.) did not affect salivation and lacrimation induced by oxotremorine (1 mg/kg s.c.), a cholinergic agonist, whereas it (25-50 mg/kg) reduced the oxotremorine-induced tremor in part. These results indicated that duloxetine produced behavioral and electroencephalographic responses resulting from the inhibition of norepinephrine and serotonin reuptake in vivo, and that it had a weak anticholinergic action. Therefore, duloxetine may be clinically useful as an antidepressant.

B-cell prolymphocytic leukemia expressing CD13 antigen

Although the expression of myeloid-associated antigen CD13 has been reported in aggressive B-cell chronic lymphocytic leukemia, its expression in other mature B-cell neoplasms appears to be rare. We report a 74-year-old female with B-cell prolymphocytic leukemia (B-PLL) expressing CD13 antigen. On admission, splenomegaly was noted. Hematological examination revealed a platelet count of 90 x 10(9)/l and a white cell count of 68 x 10(9)/l with 73% PLL cells. The hemoglobin concentration was 10.6 g/dl. A bone marrow aspirate showed a normocellular marrow with 64% PLL cells. Surface marker analysis of the PLL cells was positive for CD11b, CD13, CD19, CD20, CD24, HLA-DR, FMC7, mu and lambda. Simultaneous expression of CD13 and CD19 antigen was confirmed by dual color flow cytometry. Southern blot analysis of DNA from circulating mononuclear cells gave a rearranged band for the immunoglobulin gene (JH) but not for TCR-beta. Cytogenetic analysis of marrow cells showed an abnormal karyotype involving numbers 1, 7, 10, 12, 14, 15 chromosomes.

On the beta-glucuronidase binding protein (BGBP) of microorganisms. Its purification, the antiserum preparation against that and its localization in leproma and the other infectious lesions shown by immunohistologic method

Our previous studies suggested that M. leprae (ML) grow in peripheral nerves and lepra cells because ML metabolize hyaluronic acid (HA), and use its component for their growth by the aid of host enzyme combined to the bacilli derived beta-glucuronidase binding protein (BGBP). In this study, therefore, we examined the method to purify BGBP from a mycobacterium HI-75 originally separated from a leproma and cultured by modified Ogawa's medium containing split products of HA (glucuronic acid and N-acetylglucosamine). The distribution of BGBP in leproma and the other lesions consisting of hepatitis B virus infected liver and M. avium-intracellulare infected lung tissue were also immunohistologically examined. As the result, the best method to get BGBP was preparatory electrophoresis in the final step of the purification and not the molecular sieving. The BGBP was actually proven in leproma and the other infected tissues as described, indicating the abilities of these microorganisms to utilize the metabolic machinery of the host with the similar ways to that of ML.

Pharmacological studies on a new dihydrothienopyridine calcium antagonist, S-312-d. 5th communication: anticonvulsant effects in mice

S-312, S-312-d, but not S-312-l, L-type calcium channel antagonists, showed anticonvulsant effects on the audiogenic tonic convulsions in DBA/2 mice; and their ED50 values were 18.4 (12.8-27.1) mg/kg, p.o. and 15.0 (10.2-23.7) mg/kg, p.o., respectively, while that of flunarizine was 34.0 (26.0-44.8) mg/kg, p.o. Although moderate anticonvulsant effects of S-312-d in higher doses were observed against the clonic convulsions induced by pentylenetetrazole (85 mg/kg, s.c.) or bemegride (40 mg/kg, s.c.), no effects were observed in convulsions induced by N-methyl-D-aspartate, picrotoxin, or electroshock in Slc:ddY mice. S-312-d may be useful in the therapy of certain types of human epilepsy.

Alterations in the stimulatory G protein of the rat liver after partial hepatectomy

In adult male rat livers, cAMP generation in response to beta-adrenergic agonists was dramatically stimulated after partial hepatectomy. Quantitation of the alpha subunits of the stimulatory G protein (Gs alpha) using ADP-ribosylation catalyzed by cholera toxin revealed the increment in the amounts of two forms of Gs alpha, Gs alpha-S and Gs alpha-L, during liver regeneration. These increases in the amounts of both Gs alpha proteins were associated with the stimulation in their mRNA levels. In addition, partial hepatectomy gave rise to a shift in the proportion of beta-adrenergic receptor (beta-AR) in the high affinity state produced by beta-AR-Gs complex. The susceptibility of Gs alpha to trypsin was used as a probe for beta-AR-Gs coupling. The GTP-bound forms of both Gs alpha-S and Gs alpha-L were more trypsin-sensitive than their GDP-bound forms. Preincubation of liver plasma membranes prepared from partially hepatectomized rats with the agonist isoproterenol resulted in an enhancement of trypsin-sensitivity of Gs alpha-L, but not Gs alpha-S. This effect was retarded by the addition of the antagonist propranolol. We conclude that the increase in the amount of Gs alpha can be contributed to the rise in beta-response after partial hepatectomy, and suggest that beta-AR is preferentially coupled with Gs alpha-L rather than Gs alpha-S.

Influence of potassium concentration in microdialysis perfusate on basal and stimulated striatal dopamine release: effect of ceruletide, a cholecystokinin-related peptide

The in vivo microdialysis method was used to study the effect of the cholecystokinin-related peptide, ceruletide, on extracellular levels of dopamine (DA) in the striatum following perfusion with various K+ concentrations. Increasing the K+ concentration in the perfusate from 4 to 15 or 17.5 mM did not change basal DA release or release evoked by electrical stimulation of the medial forebrain bundle (MFB). However, when the perfusing solution contained 20 or 30 mM K+, dose-dependent reductions of both basal and MFB-stimulated DA release occurred. Subcutaneous administration of ceruletide at 160 micrograms/kg had no influence on the basal or MFB-stimulated DA release with 4 or 15 mM K+ in the perfusate. However, after perfusion with 17.5 mM K+, ceruletide significantly attenuated the basal and MFB-stimulated DA release. Carbachol (10 microM) locally applied via the dialysis probe also attenuated MFB-stimulated DA release after perfusion with 17.5 mM K+. From these results, we conclude that under appropriate depolarization of striatal DA terminals, ceruletide induces further depolarization and inactivation of nigrostriatal DA terminals. The present data suggest that this effect may be mediated via intrinsic cholinergic neurons in the striatum.

Benzodiazepine inverse agonists augment long-term potentiation in CA1 and CA3 of guinea pig hippocampal slices

The effects of benzodiazepine inverse agonists on the long-term potentiation of synaptic transmission in hippocampal slices of the guinea pig were examined using an extracellular recording technique. Benzodiazepine inverse agonists, beta-carboline-3-carboxylate (beta-CCE), 2-phenylpyrazolo [4,3-c]quinolin-3(5H)-one (CGS-8216) and 2-[5-methylthien-3-yl]-2,5-dihydro-3H-pyrazolo [4,3-c]quinolin-3-one (S-135), augmented the magnitude of long-term potentiation induced by tetanic stimulation of input fibers in both the CA1 and the CA3 regions. beta-Carboline-3-carboxylate was more effective in augmenting long-term potentiation in CA1 than in CA3. Augmentation of long-term potentiation produced by beta-CCE was antagonized by concomitant application of flumazenil, a benzodiazepine receptor antagonist. Therefore, the enhancing action of benzodiazepine inverse agonists on long-term potentiation, which is suggested to be a specific action, mediated by the GABA/benzodiazepine receptor complex, might help to explain the mechanism of the memory-enhancing effects of benzodiazepine inverse agonists, observed in some in vivo behavioral paradigms.

Differential effects of ceruletide on amphetamine-induced behaviors and regional dopamine release in the rat

This study concerned the effects of ceruletide, a cholecystokinin (CCK)-related peptide, on amphetamine-stimulated behaviors (hyperlocomotion and stereotypy) and amphetamine-induced dopamine (DA) release from the striatum and the nucleus accumbens of the rat. Also, behavioral alterations due to ceruletide administration were compared with the change in DA release from these areas. Ceruletide 160 micrograms/kg s.c., attenuated hyperlocomotion induced by amphetamine, 1 mg/kg and 3 mg/kg s.c., but had no effect on amphetamine-induced stereotypy. Results from in vivo microdialysis experiments showed that s.c. administration of ceruletide caused a significant inhibition of the amphetamine-induced increase in DA release in the nucleus accumbens but not in the striatum. These neurochemical inhibitory effects of ceruletide disappeared completely with bilateral subdiaphragmatic vagotomy. However, infusion of 1 microM of ceruletide into the nucleus accumbens through the dialysis probe had no effect on amphetamine-induced DA release. These results suggest that the inhibitory effect of peripheral administration of ceruletide on amphetamine-induced hyperlocomotion is closely related to the change in DA release from the nucleus accumbens. In the nucleus accumbens, systemically administered ceruletide acts initially on the peripheral organs and influences the activity of DA terminals via an unknown path related to the vagus. Ceruletide had different actions on the dopaminergic system in the striatum and that in the nucleus accumbens.

Ceruletide, a CCK-like peptide, attenuates dopamine release from the rat striatum via a central site of action

Ceruletide (CLT), a cholecystokinin-like peptide was given subcutaneously or via the perfusate to rats to clarify the site of action (peripheral vs. central location) of CLT, using in vivo microdialysis techniques. Striatal dopamine (DA) release induced by haloperidol (HPD) was significantly inhibited by subcutaneously administered CLT (160 micrograms/kg) when given with a perfusate containing 15 mM K+. Subdiaphragmatic vagotomies failed to block the inhibitory effect of CLT. CLT (10(-15)-10(-11) M) locally applied, via a dialysis tube, produced an inhibitory effect on HPD-induced DA release in the striatum in a dose-dependent manner. The inhibitory effect of CLT given subcutaneously on DA release was antagonized by both locally applied proglumide and systemically administered L-365,260. These findings suggest that systemically administered CLT can directly act on the striatal neurons via CCK-B receptors and produce an inhibitory effect on DA release in the striatum under appropriate depolarization.

Inhibitory effect of CCK-8 and ceruletide on glutamate-induced rises in intracellular free calcium concentrations in rat neuron cultures

To study the mechanism by which cholecystokinin octapeptide (CCK-8) and its potent analogue, ceruletide, prevent glutamate-induced neuronal cell death in rat neuron cultures, we examined the effect of both peptides on glutamate-induced increases in the intracellular free calcium concentrations ([Ca2+]i), which are known to be a crucial trigger of the neurodegeneration induced by glutamate. CCK-8 itself did not alter [Ca2+]i in rat neuron cultures. Glutamate increased [Ca2+]i in neuron cultures rapidly and markedly. CCK-8 and ceruletide significantly suppressed the increases in [Ca2+]i induced by glutamate. The maximum inhibitory effects of CCK-8 and ceruletide at 10(-6) M reached 43 and 46% of the response to glutamate, respectively. Gastrin-I and CCK-4 also significantly attenuated the increases in [Ca2+]i induced by glutamate. The inhibitory effect of CCK-8 was completely blocked by the selective antagonist for CCK-B receptors, (+)L-365,260, but not by (-)L-364,718, which is a selective antagonist for CCK-A receptors. CCK-8 significantly suppressed [Ca2+]i response to kainate and high concentrations of extracellular K+, but not to N-methyl-D-aspartate. With cultured astrocytes, CCK-8 did not inhibit the increment of [Ca2+]i induced by glutamate. These findings clearly demonstrated that CCK-8 and ceruletide inhibit glutamate-induced increases in [Ca2+]i in neuron cultures through CCK-B receptors, suggesting that CCK-8 may participate in the central actions of glutamate.

Systemic administration of a cholecystokinin analogue, ceruletide, protects against ischemia-induced neurodegeneration in gerbils

The neuroprotective action of a cholecystokinin octapeptide analogue, ceruletide, was evaluated in models of cerebral ischemia using Mongolian gerbils. Ceruletide significantly suppressed the hyperactivity and amnesia induced by ischemia when injected s.c. 30 min before 5-min occlusion of the bilateral common carotid arteries at room temperature or immediately after their reperfusion. Ceruletide also reduced behavioral changes in ischemic gerbils whose body temperature was maintained at 37 degrees C during the 3-min occlusion. In these groups, delayed neuronal cell death in the hippocampal CA1 area following ischemia was markedly attenuated by s.c. administration of ceruletide. On the other hand, ceruletide could not inhibit the behavioral changes or the neurodegeneration induced in the hippocampal CA1 area by 5-min occlusion at 37 degrees C. These findings indicate that peripheral injection of ceruletide produces a neuroprotective action against moderate cerebral ischemia, which is the first evidence suggesting the efficacy of ceruletide in neurodegenerative diseases.

[Clinical evaluation of traditional Chinese medicine for chronic idiopathic thrombocytopenic purpura]

The efficacy of traditional Chinese medicine (Kampo medicine) was examined in 40 patients with steroid-unresponsive idiopathic thrombocytopenic purpura (ITP). All patients were, at first, given Hochuekihi-to, and when they were refractory, therapy was switched to Sairei-to, Ninjinyoei-to, and Kamikihi-to. The efficacy rate was 20.0% by Hochuekihi-to, 20.7% by Sairei-to, 5.5% by Ninjinyoei-to and 6.7% by Kamikihi-to, respectively. Thus, overall responders were 12 in 40 patients with an effective rate of 30.0%. The mechanism of action of traditional Chinese medicine is discussed in relation to the production of various kinds of cytokines.

Activation of CCK-A receptors induces elevation of plasma corticosterone in rats

Cholecystokinin octapeptide (CCK-8) and ceruletide (1 microgram/kg) produced a pronounced increment of plasma corticosterone levels at 30 min after intraperitoneal administration. The response to these peptides was suppressed by pretreatment with a selective antagonist for CCK-A receptors, (-)L-364,718, in a dose-related manner, but not with an antagonist for CCK-B receptors, (+)L-365,260. However, (-)L-364,718 itself had no effect on basal levels of plasma corticosterone. These results indicate that peripheral administration of CCK-8 and ceruletide stimulates the hypothalamo-pituitary adrenal axis through the activation of CCK-A receptors, but not CCK-B receptors.