Effect of glycosidase inhibitors on the biosynthesis of alpha 2-plasmin inhibitor and antithrombin III in Hep G2 cells.

We studied the effect of the glucosidase I inhibitor, N-methyl-1-deoxynojirimycin (MdN) and the mannosidase inhibitor, 1-deoxymannojirimycin (dMM) on the biosynthesis and secretion of alpha 2-plasmin inhibitor (alpha 2-PI) and antithrombin III (ATIII) in cultures of human hepatoma (Hep-G2) cells. Incubation with 1 mM MdN decreased secreted alpha 2-PI activity and antigen levels by about 40%, whereas those of ATIII were not affected. Neither inhibitor affected the messenger RNA levels as determined by Northern blotting. Pulse-chase studies using [35S]-methionine showed that MdN decreased alpha 2-PI and ATIII secretion rates. By the 18 h chase, MdN had decreased secreted alpha 2-PI to 50-60%, with little effect on ATIII. Intracellular forms of alpha 2-PI or ATIII synthesized by cells treated with 1 mM MdN were sensitive to endoglycosidase H (Endo H), whereas almost all the secreted forms were resistant, suggesting the presence of complex-type oligosaccharides. In the presence of 1 mM dMM, cells synthesized Endo H-sensitive alpha 2-PI and ATIII with similar secretion rates. These results suggest that retention of glucose on N-linked oligosaccharides not only retards the exit of alpha 2-PI and ATIII, but also changes the catabolic rate of alpha 2-PI in the endoplasmic reticulum.

Analyzing redox balance in a synthetic yeast platform to improve utilization of brown macroalgae as feedstock.

Macroalgae have high potential to be an efficient, and sustainable feedstock for the production of biofuels and other more valuable chemicals. Attempts have been made to enable the co-fermentation of alginate and mannitol by Saccharomyces cerevisiae to unlock the full potential of this marine biomass. However, the efficient use of the sugars derived from macroalgae depends on the equilibrium of cofactors derived from the alginate and mannitol catabolic pathways. There are a number of strong metabolic limitations that have to be tackled before this bioconversion can be carried out efficiently by engineered yeast cells. An analysis of the redox balance during ethanol fermentation from alginate and mannitol by Saccharomyces cerevisiae using metabolic engineering tools was carried out. To represent the strain designed for conversion of macroalgae carbohydrates to ethanol, a context-specific model was derived from the available yeast genome-scale metabolic reconstructions. Flux balance analysis and dynamic simulations were used to determine the flux distributions. The model indicates that ethanol production is determined by the activity of 4-deoxy-l-erythro-5-hexoseulose uronate (DEHU) reductase (DehR) and its preferences for NADH or NADPH which influences strongly the flow of cellular resources. Different scenarios were explored to determine the equilibrium between NAD(H) and NADP(H) that will lead to increased ethanol yields on mannitol and DEHU under anaerobic conditions. When rates of mannitol dehydrogenase and DehRNADH tend to be close to a ratio in the range 1-1.6, high growth rates and ethanol yields were predicted. The analysis shows a number of metabolic limitations that are not easily identified through experimental procedures such as quantifying the impact of the cofactor preference by DEHU reductase in the system, the low flux into the alginate catabolic pathway, and a detailed analysis of the redox balance. These results show that production of ethanol and other chemicals can be optimized if a redox balance is achieved. A possible methodology to achieve this balance is presented. This paper shows how metabolic engineering tools are essential to comprehend and overcome this limitation.

Hypocholesterolemic action of a novel delta8-dihydroabietamide derivative, THD-341, in rats.

The hypocholesterolemic properties of THD-341, N-(2,6-dimethylphenyl)-delta8-dihydroabietamide, were studied in rats. THD-341 reduced serum cholesterol levels in cholesterol-cholate-fed rats at a concentration of less than 0.001% in the diet or an oral dose of less than 3 mg/kg, once a day. When compared in terms of the 50% inhibitory dose for serum cholesterol elevation (ID 50%, % in diet), THD-341 (0.0008%) was comparable to D-thyroxine (0.0005%), more potent than estradiol (0.003%), and far more potent than clofibrate (0.2%), beta-sitosterol (0.8%), cholestyramine (2%), or nicotinic acid (3%). A daily intravenous injection of THD-341 was also effective (ID 50%: 7 mg/kg). THD-341 reduced serum and liver cholesterol in rats made hypercholesterolemic by 0.3% dietary thiouracil or 0.25% dietary cholate. Liver cholesteriol was more profoundly affected than the serum cholesterol. In normal rats, cholesterol was reduced in liver but not in serum. Its mechanism of action is unknown but the results suggest that THD-341 inhibits cholesterol absorption or re-absorption.

Effect of THD-341, a new hypocholesterolemic agent, on experimental atherosclerosis in rabbits.

The influence of THD-341, N-(2,6-dimethylphenyl)-delta8-dihydroabietamide, upon the formation and regression of atherosclerosis and on serum and liver lipid levels has been studied. When rabbits were fed a 1% cholesterol diet for 7 weeks, THD-341 added at a dietary level of 0.01% during the last 4 weeks almost completely prevented the formation of atherosclerotic lesions and the elevation of serum and liver cholesterol levels. When the drug was fed for 10 weeks, either in the normal or cholesterol diet, to rabbits with pre-established atherosclerosis induced by cholesterol feeding for 11 weeks, it did not affect the extent or severity of the lesions but inhibited the progression of lipid deposition in the aorta in a group fed the cholesterol diet during the final 10-weeks period. The reduction of serum and liver cholesterol levels was greater in the drug-treated groups than in the normal rabbit chow-fed group.

Hypolipidemic effect of NS-1 and other related drugs in rhesus monkeys.

NS-1, 4-[2-(4-isopropylbenzamido)ethoxy]benzoic acid, is a novel chemical compound which has been found to be a potent hypolipidemic agent in rhesus monkeys. Significant reductions in serum cholesterol and phospholipids were observed in normolipidemic monkeys following oral doses of 30-300 mg/kg/day. A dose of 300 mg/kg/day for 28 days lowered serum cholesterol and phospholipid levels by 49% and 41%, respectively. NS-1 was more potent than clofibrate, clinofibrate, simfibrate, bezafibrate, gemfibrozil, nicomol and probucol in hypolipidemic activity in the same model. Lipoprotein analysis showed that NS-1 reduced low density lipoprotein much more than high density lipoprotein. The results suggest that NS-1 may have hypolipidemic activity in hyperlipidemic patients.

Involvement of metabotropic glutamate receptors in Gi- and Gs-dependent modulation of adenylate cyclase activity induced by a novel cognition enhancer NS-105 in rat brain.

The effect of a novel cognition enhancer [(+)-5-oxo-D-prolinepiperidinamide monohydrate] (NS-105) on cAMP formation was investigated in both slices and membranes of the rat cerebral cortex. NS-105 (10(-8)-10(-6) M) inhibited forskolin-stimulated cAMP formation in membranes, however, the compound significantly enhanced the cAMP formation in pertussis toxin-pre-treated membranes, an action that was abolished by cholera toxin. In contrast, in digitonin-permeabilized membranes, NS-105 had no influence on Mn2+-stimulated cAMP formation. Both of the inhibitory and facilitatory actions of NS-105 on cAMP formation were mimicked by a metabotropic glutamate receptor (mGluR) agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) and an adrenergic alpha2 agonist UK-14,304, and blocked by a mGluR antagonist 2-amino-3-phosphonopropanoate but not by an alpha2 antagonist yohimbine. In cortical slices, NS-105 (10(-8)-10(-7) M) inhibited forskolin-stimulated cAMP accumulation but enhanced isoproterenol-stimulated cAMP accumulation, as did by a GABA(B) agonist (-)baclofen. On the other hand, (-)baclofen, while it significantly inhibited cAMP accumulation in slices, did no longer inhibit cAMP accumulation, when treated with NS-105 (10(-8)-10(-5) M). Similarly, (-)baclofen-induced inhibition of the cAMP accumulation was reversed by 1S,3R-ACPD and UK-14,304. NS-105 (10(-6)) increased [35S]GTPgammaS binding in the intact but not digitonin-permeabilized cortical membranes, as produced by UK-14,304, although the compound (10(-9)-10(-3) M) had no influence on various neurotransmitter receptor bindings, including alpha2 receptors. These results suggest that NS-105 modulates adenylate cyclase activity by stimulating mGluRs which might coupled to both Gi/Go and Gs.

Brain pertussis toxin-sensitive G proteins are involved in the flavoxate hydrochloride-induced suppression of the micturition reflex in rats.

The effect of flavoxate hydrochloride (flavoxate), an anti-pollakiurea agent, on cyclic AMP (cAMP) formation was investigated in the rat brain and a possible involvement of brain G proteins in the action of flavoxate on the bladder function was subsequently examined. Flavoxate (10(-8)-10(-5) M) inhibited cAMP formation in a concentration-dependent manner, an action which was completely abolished by pretreating the membranes with pertussis toxin (PTX). The inhibitory effect of flavoxate was also completely antagonized by combined treatment with any two antagonists for adenosine A1 (8-cyclopentyl-1,3-dipropylxanthine), dopamine D2 (sulpiride) or adrenergic alpha 2 (yohimbine) receptors, although each antagonist alone did not significantly block the flavoxate-induced inhibition of cAMP formation. Radioligand binding studies indicated that flavoxate at micro- or submicromolar concentrations has affinity for Gi-coupled receptors such as A1, D2 and alpha 2 receptors. Therefore, flavoxate may inhibit cAMP formation by the stimulation of A1, D2 and alpha 2 receptors. To clarify the involvement of brain Gi proteins in the flavoxate-induced inhibition of the micturition reflex, the effect of pretreatment with PTX (i.c.v.) on the flavoxate-induced inhibition of isovolumetric rhythmic bladder contractions was examined in rats. Flavoxate (3 mg/kg, i.v.) completely abolished rhythmic bladder contractions in vehicle-pretreated rats, but not in PTX-pretreated rats. These findings suggest that signal transduction via Gi-coupled receptors is involved, at least in part, in the inhibition of the micturition reflex by flavoxate in rats. These results also provide the first evidence suggesting a negative role of brain PTX-sensitive G proteins in the micturition reflex.

Na+ and high-voltage-activated Ca2+ channel blocking actions of NS-7, a novel neuroprotective agent, in NG108-15 cells.

The actions of a novel neuroprotective compound, 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy)pyrimidine hydrochloride (NS-7), on voltage-gated Na+, Ca2+ and K+ channels were investigated in a mouse neuroblastoma and rat glioma hybrid cell line, NG108-15, using a whole-cell voltage clamp technique. NG108-15 cells have a tetrodotoxin-sensitive Na+ channel, three types of Ca2+ channel (L, N and T) and voltage-gated K+ channels, all of which were inhibited by NS-7 in a concentration-dependent manner. However, there was a considerable difference in its potency: the IC50 values for the tetrodotoxin-sensitive Na+ channel, L-type Ca2+ channel and N-type Ca2+ channel were similar (7.8, 4.5 and 7.3 microM, respectively), lower than the IC50 value for the T-type Ca2+ channel (17.1 microM), and much lower than the IC50 value for the voltage-gated K+ channel (160.5 microM). NS-7 altered neither the shape nor the reversal potential of the current-voltage curves for Na+, L-type or N-type Ca2+ channels, although the currents were reduced at every potential tested. These results indicate that NS-7 is a Na+ and high-voltage-activated (L- and N-type) Ca2+ channel blocker, and its channel-blocking properties may contribute to its neuroprotective action.

Effect of a novel cognition enhancer NS-105 on learned helplessness in rats: possible involvement of GABA(B) receptor up-regulation after repeated treatment.

We have previously found that a cognition enhancer [(+)-5-oxo-D-prolinepiperidinamide monohydrate] (NS-105) reversed the inhibition of cyclic AMP formation induced by the GABA(B) receptor agonist baclofen. The GABA(B) receptor has been implicated in the pathophysiology of depressive illness. The present experiment was designed to evaluate the antidepressant activity of NS-105 in the forced swimming and learned helplessness tests in rats. NS-105 (1-100 mg/kg, p.o.) significantly decreased immobility time in the forced swimming test, an effect similar to that of desipramine. Repeated administration of NS-105 also reversed the failure to escape in the shuttle-box test of rats previously exposed to inescapable footshock. Biochemical data showed that repeated administration of NS-105 increased the number of GABA(B) receptors in rat cerebral cortex without affecting the binding properties of beta-adrenoceptors and 5-HT2 receptors. In contrast to other antidepressants, NS-105 did not inhibit monoamine uptake in vitro, nor did it change monoamine concentrations in brain tissues or extracellular fluids. These findings suggest that NS-105, which lacks an effect on monoaminergic systems, has potent antidepressant activity, which may involve up-regulation of GABA(B) receptors after repeated administration.

NS-49, an alpha 1A-adrenoceptor agonist, selectively increases intraurethral pressure in dogs.

The effects of NS-49 ((R)-(-)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethane sulfonanilide hydrochloride), an alpha 1A-adrenoceptor-selective agonist, on intraurethral pressure and blood pressure were investigated in anesthetized dogs. In addition, the contractile effects of NS-49 on the isolated dog urethra and carotid artery were compared with those of non-selective alpha 1-adrenoceptor agonists. Intravenously (i.v.) administered NS-49 at 0.3 microgram/kg or more significantly increased intraurethral pressure in a dose-dependent manner. Much higher doses of NS-49 were needed to increase blood pressure. In contrast, ST-1059 (1-(2',5'-dimethoxyphenyl)-2-aminoethanol) (an active metabolite of midodrine) at 30 micrograms/kg or more significantly increased both intraurethral pressure and blood pressure. NS-49 was 11-fold more selective for intraurethral pressure than ST-1059, NS-49, ST-1059, phenylephrine and noradrenaline caused concentration-dependent contraction of the isolated dog urethra. NS-49 caused only a slight contraction of the dog carotid artery even at high concentrations, whereas the reference drugs caused contractions of the artery with high efficacy. The alpha 1A-adrenoceptor-selective antagonists 5-methyl-urapidil and WB-4101 also showed high affinity for alpha 1-adrenoceptors in the dog urethra in inhibiting [3H]prazosin binding. In conclusion, the alpha 1A-selective agonist NS-49 selectively increased intraurethral pressure in dogs, and produced selective contraction of the dog urethra. These results suggest that the alpha 1A-adrenoceptor subtype is responsible for the contraction of the urethra and the regulation of intraurethral pressure, and that NS-49 might be useful for the treatment of stress incontinence with little effect on the cardiovascular system.

Inhibitory effects of NS-21, a novel drug for urinary incontinence, and its active metabolite, RCC-36, on L-type calcium currents in isolated guinea pig detrusor smooth muscle cells.

The inhibitory effects of NS-21, a newly developed drug for the treatment of urinary frequency and urinary incontinence, and its active metabolite, RCC-36, on L-type Ca2+ currents (ICa) in guinea pig detrusor smooth muscle cells have been compared to those of terodiline by a whole-cell patch-clamp technique. Like terodiline (10 microM), both NS-21 (10 microM) and RCC-36 (10 microM) induced a sizeable decrease in ICa elicited from a holding potential of -60 mV without changing the current-voltage relationship. The three drugs shifted the inactivation curves for ICa in the hyperpolarizing direction by 13 to 20 mV but had no effect on the activation curves for ICa resulting in a decrease in the calcium window current. The inhibitory effects of NS-21 and RCC-36 were greater than those of terodiline. The three drugs inhibited ICa in a concentration- and holding-potential-dependent manner. The IC50 values at a holding potential of -60 mV were 7.9 microM for NS-21, 6.4 microM for RCC-36, and 5.9 microM for terodiline, and at -40 mV they were 1.3, 1.2, and 3.5 microM, respectively. The ratio calculated by dividing the IC50 value at -60 mV by the value at -40 mV was 6.1, 5.3 and 1.7, respectively, indicating that the inhibitory effects of NS-21 and RCC-36 on ICa were more sensitive to voltage than those of terodiline. These results suggest that NS-21 and RCC-36 could be more effective in the treatment of urinary bladder ailments, such as urinary frequency and urinary incontinence.

A novel cognition enhancer NS-105 modulates adenylate cyclase activity through metabotropic glutamate receptors in primary neuronal culture.

The effect of (+)-5-oxo-D-prolinepiperidinamide monohydrate (NS-105), a novel cognition enhancer, on adenylate cyclase activity was investigated in cultured neurons of the mouse cerebral cortex. NS-105 (10(-7) and 10(-6) M) inhibited forskolin-stimulated cyclic AMP formation, an action that was dependent on pertussis toxin-sensitive G proteins. Conversely, in pertussis toxin-pretreated neurons, NS-105 (10(-7)-10(-5) M) significantly enhanced the forskolin-stimulated cyclic AMP formation, and this action was completely reversed by cholera toxin. A metabotropic glutamate receptor agonist (1S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S, 3R-ACPD) produced similar bi-directional actions on the cyclic AMP formation. Both of these inhibitory and facilitatory actions of NS-105 and 1S, 3R-ACPD were blocked by L(+)-2-amino-3-phosphopropinoic acid (L-AP3). NS-105 (10(-6) M) and 1S, 3R-ACPD (10(-4) M) significantly enhanced isoproterenol- and adenosine-stimulated cyclic AMP formation. The enhancement of such Gs-coupled receptor agonists-stimulated cyclic AMP formation was also produced by quisqualate but not by L(+)-2-amino-4-phosphonobutanoate (L-AP4). The phosphoinositides hydrolysis was enhanced by 1S, 3R-ACPD (10(-4) M) but not by NS-105 (10(-6) M), however, 1S, 3R-ACPD-induced increase in phosphoinositides turnover was attenuated by NS-105. These findings suggest that NS-105 stimulates metabotropic glutamate receptor subclasses that are coupled both negatively and positively to adenylate cyclase, but it acts as an antagonist at the receptor subclasses that are linked to phosphoinositides hydrolysis.

Blockade of voltage-sensitive sodium channels by NS-7, a novel neuroprotective compound, in the rat brain.

The effects of 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride (NS-7), a novel neuroprotective compound, on the voltage-sensitive sodium channels (VSSC) were examined in the rat brain and cardiac myocytes. NS-7 inhibited [3H]batrachotoxinin A 20 alpha-benzoate (BTX) binding (neurotoxin receptor site 2) in brain membranes with a Ki value of 1 microM, while the compound was less effective in the cardiac myocytes (Ki = 13 microM). Aconitine, on the other hand, inhibited [3H]BTX binding to brain membranes and cardiac myocytes with the same potency. In contrast. NS-7 had no affinity for [3H]saxitoxin binding in brain (neurotoxin receptor site 1). In superfused slices of the rat cerebral cortex, NS-7 inhibited the veratridine (5 microM)-evoked glutamate release in a concentration-dependent manner, the IC50 value of which was 7.7 microM, whereas the compound showed a weak and not significant suppression of KCl-evoked glutamate release. The tissue concentrations of NS-7 in the rat cerebral cortex and heart were 89 and 28 nmole/g tissue, respectively, 5 min after its intravenous injection (8 mg/kg). Furthermore, in the cerebral cortex, NS-7 distributed preferentially to the membrane-enriched synaptosomal fraction. Since neurotoxin receptor site 2 is located in the transmembrane region of the VSSC moiety, the channel function may be substantially inhibited by a peripheral administration of NS-7. These results suggest that the blockade of neurotoxin receptor site 2 of VSSC in the brain contributes to the neuroprotective action of NS-7.

Cardiac electrophysiological actions of NS-21 and its active metabolite, RCC-36, compared with terodiline.

Terodiline, an anticholinergic drug with a Ca2+ blocking action, is thought to be associated with torsade de pointes, a serious ventricular tachycardia. NS-21 is a newly developed drug for the treatment of urinary frequency and urinary incontinence and it has pharmacological properties similar to those of terodiline. It remains unknown, however, whether NS-21 and its active metabolite, RCC-36, have any proarrhythmic activity. The electrophysiological properties of NS-21 and RCC-36 were examined in guinea pig ventricular myocytes and were compared with those of terodiline using the whole-cell patch-clamp technique. NS-21, RCC-36 and terodiline inhibited L-type Ca2+ currents in a concentration-dependent manner with IC50 values of 27.0, 27.0 and 33.5 microM, respectively. At a concentration of 10 microM, terodiline inhibited both the time-dependent current and the tail current of the delayed rectifier K+ current, with the latter being significantly inhibited at voltages more positive than +10 mV. In contrast, NS-21 and RCC-36 had almost no effect on either of these currents. Terodiline also inhibited the inward rectifier K+ current significantly at voltages more negative than -100 mV, whereas NS-21 and RCC-36 had little effect. If the proarrhythmic activity of terodiline resulted primarily from the combined inhibition of K+ and Ca2+ currents, one might expect that NS-21 and RCC-36, which inhibit L-type Ca2+ currents without affecting either the delayed rectifier K+ current or the inward rectifier K+ current, would not share the proarrhythmic activities of terodiline.

Permeability of a neuroprotective compound NS-7 into brain: comparison between normal and middle cerebral artery-occluded rats.

The pharmacokinetics of 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride (NS-7), a novel neuroprotective compound, in brains of normal and ischemic rats were investigated. In normal rats, the concentrations of NS-7 in the cerebral cortex and striatum were more than 10-folds higher than those in plasma during 5 min and 12 h after intravenous injection. The time course changes in plasma concentration of NS-7 were fitted to the two-compartment open model, in which elimination half-life (t(1/2)beta) was 6.0 h and distribution volume (V1) was 4.4. The estimated striatal interstitial concentration of NS-7 measured by microdialysis was unexpectedly low and almost constant after intravenous injection. Subsequently, the level of NS-7 in brain was compared between sham-operated and middle cerebral artery (MCA)-occluded rats. In MCA-occluded rats, the concentrations of NS-7 in the ischemic cerebral cortex and striatum were 64-71% of those in sham-operated group at 1 h after injection, although the initial concentrations (at 2-5 min) were much lower (about 20%) in MCA-occluded rats. The t(max) was observed at 1 h after injection, which was later than that (5 min) determined in sham-operated rats. Moreover, its elimination half-life was longer in MCA-occluded rats than in sham-operated animals. From these results it is suggested that peripherally administered NS-7 readily penetrates into brain, in which it exists for the most part in parenchymal fraction. In addition, substantial amount of NS-7 may distribute to the ischemic brain regions when it was injected after MCA occlusion.

Detection of Clostridium botulinum in natural sweetening.

Various sugar products were examined for contamination with C. botulinum spores. Type A, B and C spores were detected in three of 56 samples of sugar for apiculture, which may attest the significance of bee-feed as a source of contamination of honey. The heavy contamination of honey with C. botulinum spores sometimes encountered, however, can not be explained unless some other factors, e.g., that allowing germination and multiplication of the spores somewhere during honey production, are found. Type A spores were detected in some samples of raw sugar and molasses and also in two of 41 samples of brown sugar lump, but not in refined sugar or other various samples taken at a sugar factory or in sugar cane left on the field in Okinawa. The fact that some natural sweetenings are contaminated with C. botulinum spores, even in low concentrations, may be food-hygienically important.

NS-3, a TRH-analog, reverses memory disruption by stimulating cholinergic and noradrenergic systems.

The effects of a TRH-analog, N[[(3R,6R)-6-methyl-5-oxo-3-thiomorpholinyl]carbonyl]-L-histidyl-L - prolinamide tetrahydrate (NS-3, CG3703, montirelin hydrate) were compared with those of physostigmine on learning and memory disruption in the passive avoidance response (PAR) induced by either electrolytic lesion of the nucleus basalis magnocellularis (NBM) or by treatment with the noradrenergic neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4) in rats. a) In NBM-lesioned rats, both NS-3 and physostigmine significantly reversed disruption of memory consolidation examined 15 min after the training session when these drugs were injected IP immediately after the training session. In addition, reversal by NS-3 (0.1 mg/kg) of the disruption of memory was observed even in the retention test conducted 24 h after the training session. b) NS-3 (0.5 mg/kg) significantly reversed the disruption of memory retrieval, when the drug was administered 15 min before the test session. c) DSP4 (50 mg/kg IP) caused memory disruption when the retention tests were conducted between 1 and 48 h after the acquisition session. NS-3 (0.1 mg/kg), but not physostigmine, significantly reversed the disruption of memory induced by DSP4 treatment. These findings suggest that the consistent antiamnestic action of NS-3 is due to the enhancement of both central cholinergic and noradrenergic systems, possibly via facilitation of the release of these transmitters.

Diet-induced atherosclerosis in cynomolgus monkey aorta and regression by the sixth-month observation.

Pathomorphologic analysis was employed to evaluate diet-induced atherosclerosis in cynomolgus monkey aorta and regression by administration of a hypolipidemic agent for six months after the atherogenic ration. Twenty-seven male cynomolgus monkeys were divided into three groups. Group A was fed individually with a high-fat diet containing 0.3% cholesterol under identical conditions for six months. Group B was fed with normal monkey chow for six months after the same atherogenic ration. Group C was fed with normal monkey chow and administered a hypolipidemic agent 1% of 4-[2-(4-isopropylbenzamido)ethoxy] benzonic acid for six months after the same atherogenic ration. Each thoracic and abdominal aorta of animal models was separately analyzed. Lipid composition analysis and esterified cholesterol (CE) in aortic wall, ratio of free cholesterol to phospholipid, surface involvement, and atherosclerotic index after Sudan IV staining were studied for evaluation of progression and regression. The configurations of atherosclerotic involvement were histologically evaluated among each group. These observed lesions, features specific to cynomolgus lesions, mainly consisted of lipid-rich foam cells, lipid debris, and proliferated extracellular matrix. No different lesion composition was noted between the thoracic and abdominal aorta. This may suggest that some local factors play an important role for development of atherosclerosis after the initial event. Group C had remarkable reduction of foam cells and of CE accumulation in both the thoracic and abdominal aortic wall. Accelerated regression in group C as compared with group B was demonstrated both biochemically and pathohistologically. These results suggest that substantial regression of atherosclerosis in both the thoracic and abdominal aorta can be expected. This hypolipidemic agent exerts notable antiatherosclerotic activity, along with a lowering effect on plasma total cholesterol levels.