Early intervention for very-low-birth-weight infants

To assess the efficacy of early intervention (EI) for very-low-birth-weight (VLBW) infants, we evaluated 62 2 year old children who were enrolled in an EI program and 48 control subjects aged 2 years. We determined the subjects' developmental quotients (DQ) and obtained information about the parents' evaluation of the children from a questionnaire sent to the parents. There was no significant difference in the DQ between the EI group and the control group. However, based on the responses to the questionnaire, subjects in the EI group showed slight, but statistically marginally significant, improvements in behavioral problems, especially a decrease in hyperkinesia, in adjusting to a circadian sleep cycle, and an improvement in language development, as compared with the control group (P < 0.1). Thus, EI for VLBW infants is considered useful to enhance some areas of development.

Apoptotic cell death in atherosclerotic plaques of hyperlipidemic knockout mice

In an attempt to understand the roles of apoptosis in the development of atherosclerosis, we classified lesions developed in the aortas of apo E- and LDL receptor-deficient mice, murine models of atherosclerosis, and determined frequency, spatial distribution and cell types of apoptotic cells in each lesion. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and nuclear staining with propidium iodide were used to demonstrate apoptotic cells. Mean frequencies of TUNEL-positive cells were as follows: 0%, in Type I, 0.3% in Type II, 0.05% in Type III, 0.06% in Type IV and 0.06% in Type V lesions. Most of the TUNEL-positive cells were filled with fat and distributed in close proximity to lipid pools. The TUNEL-positive cells in the intimal side of the lipid cores were macrophages, while some of those in the adventitial side were smooth muscle cells. In conclusion, apoptosis is involved in the active turn-over of foam cells of both macrophage- and smooth muscle cell-lineage especially in the early atherosclerotic lesions of the hyperlipidemic mice.

Detection of genotoxicity of polluted sea water using shellfish and the alkaline single-cell gel electrophoresis (SCE) assay: a preliminary study

We exposed two species of shellfish, Patunopecten yessoensis and Tapes japonica, for 4 h to artificial sea water in which N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), ethyl nitrosourea (EMS), 3-chloro-4-dichloromethyl-5-hydroxy-2(H)-furanone (MX), or benzo[a]pyrene (B[a]P) were dissolved. We then assessed the DNA damage in cells isolated from the gills using the alkaline single-cell gel electrophoresis (SCG) assay. A statistically significant increase in DNA damage was observed for all exposures. Therefore, the alkaline SCG assay detected DNA damage in gill cells produced by direct mutagens and promutagen dissolved in sea water. T. japonica was exposed to sea water sampled from two Pacific Ocean coasts of Japanese local cities--Hachinohe (Aomori Prefecture, Tohoku) and Nakatsu (Oita Prefecture, Kyushu)--and three bay coasts of the industrial megalopolises--Tokyo, Osaka, and Kobe. A significant increase in DNA damage was observed after the exposure to sea water from Tokyo, Osaka, and Kobe, but not from Hachinohe and Nakatsu. These results suggested the utility of the alkaline SCG assay with shellfish gill cells for monitoring sea water genotoxicity.

Rapid decrease of glycogen concentration in the hearts of senescence-accelerated mice during aging

Age-related changes in glycogen concentration in the heart of SAMP8, a substrain of senescence-accelerated prone mouse, were compared with that in SAMR1, a substrain of senescence-accelerated resistant mouse. The decrease by about 50% in the glycogen concentration in the hearts of 4-8 weeks old SAMP8 was observed in comparison with that in age-matched SAMR1, whereas there was no difference in adult hearts between the two substrains. Additionally, glycogen phosphorylase activity was significantly increased (1.3-fold) in the heart of 4-8 weeks old SAMP8 without the change in glycogen synthase activity between the two substrains. At the same age, the lipid peroxide concentration was also increased (1.4-fold) in the hearts of SAMP8, suggesting that oxidative stress was involved in the early damage to the hearts of SAMP8. Furthermore, the present findings that the cardiac glycogen concentration in SAMP8 decreases more quickly than that in SAMR1 may indicate the possibility that an accelerated aging of SAMP8 is related to the early changes in the energy sources in the heart.

Effects of apo E deficiency on plasma lipid levels in mice lacking APOBEC-1

Apolipoprotein (apo) B100 mRNA undergoes site specific C to U editing, generating a stop-translation codon of apo B48 in the small intestine. This reaction is catalyzed in an editosome which contains APOBEC-1, a catalytic subunit. To clarify the functional significance of the apo B mRNA editing in lipoprotein metabolism, we have generated APOBEC-1 knockout mice and double knockout mice which are deficient in both APOBEC-1 and apo E. The apo B mRNA editing activity was markedly reduced and complete elimination of apo B48 from the plasma was observed in APOBEC-1(-/-) mice. Plasma triglyceride levels significantly increased in the double knockout mice (APOBEC-1(-/-);apo E(-/-)) as compared to apo E(-/-) mice. These results suggest that APOBEC-1(-/-) mice are a valuable model for experiments designed to understand a role of apo B mRNA editing.

Bcl-2 protein inhibits oxysterol-induced apoptosis through suppressing CPP32-mediated pathway

Oxysterols are presumed to mediate cytotoxicity of oxidized LDL in atherosclerotic lesions. To elucidate its molecular mechanism, we established murine macrophage-like P388-D1 cells which over-express Bcl-2 protein by retrovirus-mediated gene transfer. Oxysterols (7-ketocholesterol, 25-hydroxycholesterol) induced nuclear condensation and oligonucleosomal DNA fragmentation, which were partially inhibited by Bcl-2 over-expression. Though CPP32 inhibitor suppressed the cell death in control cells, it showed no additive protection in the cells over-expressing Bcl-2. These findings indicate that oxysterols induce apoptosis via Bcl-2-inhibitable and -uninhibitable pathways, and the former depends on CPP32 activation.

Skipping of exon 14 and possible instability of both the mRNA and the resultant truncated protein underlie a common cholesteryl ester transfer protein deficiency in Japan

Among the Japanese population, a G-to-A mutation at the beginning of intron 14 of the human cholesteryl ester transfer protein (CETP) gene is a frequent cause of CETP deficiency characterized by markedly increased HDL cholesterol. The resulting abnormalities responsible for null CETP deficiency were studied in detail. The CETP mRNA transcripts amplified by polymerase chain reaction from the monocyte-derived macrophages of two homozygous patients were both found to be normal except for the whole deletion of exon 14. The deletion causes a shift of reading frame and introduces a premature termination codon downstream. Examination of the macrophage RNA from heterozygotes suggested the increased instability of the abnormal mRNA in the cytoplasm, because the amount of the aberrant transcript was nearly one third that of a normal transcript in the cytoplasm, while they were equal in the nucleus. Although this indicated the synthesis of a mutant CETP that lacks about 15% at its carboxy terminus, immunoblot analysis demonstrated that the abnormal CETP was virtually absent in both the media and cell lysates of transfected COS-1 cells, which massively expressed the mutant CETP mRNA. These results elucidate the primary abnormality due to the common CETP splicing mutation to be the exon skipping of mRNA, which decreases the level of mRNA and produces a truncated protein that should be rapidly degraded intracellularly.

Differences in the expression of glucose transporter protein isoforms in human retinoblastoma cell lines

We investigated the expression of glucose transporter (GLUT) protein isoforms in two human retinoblastoma cell lines, Y79 and WERI-Rb1, by Western blotting analysis with anti-GLUT1, 2, 3, and 4 antibodies. GLUT1 and GLUT4 proteins were detected in Y79, whereas GLUT1 and GLUT3 proteins were found in WERI-Rb1. GLUT2 protein was not detected in Y79 or WERI-Rb1. Our findings are of interest because (1) the expression of GLUT protein isoforms in the two retinoblastoma cell lines was different, and (2) GLUT4 protein, the insulin-sensitive GLUT isoform, was detected in Y79. This suggests that these cell lines have different mechanisms of glucose transport.

Tranilast inhibits contraction of rat aortic smooth muscle

Recently, the anti-allergic drug tranilast has been shown to reduce the rate of coronary restenosis after percutaneous transluminal coronary angioplasty. In this study, we investigated the effect of tranilast on contraction of and Ca2+ movement in vascular smooth muscle. We measured the isometric force and fura-2-estimated intracellular Ca2+ concentrations ([Ca2+]i) of rat aortic strips. Exposure of aortic strips to tranilast (0-500 microM) dose-dependently inhibited endothelin-1-induced increases in tension and [Ca2+]i elevation of the strips. Similar inhibition by tranilast was observed in response to high K+ stimulation. These results suggest that tranilast inhibits the contraction of vascular smooth muscle by inhibiting Ca2+ mobilization, which might be related to its preventive effect on coronary restenosis after percutaneous transluminal coronary angioplasty.

Suppression of neutral cholesterol ester hydrolase activity by antisense DNA of hormone-sensitive lipase

In order to investigate the role of the hormone-sensitive lipase (HSL) gene in the activity of neutral cholesterol ester hydrolase (NCEH) from a molecular perspective, Chinese hamster ovary (CHO) cells were transfected with rat antisense hormone-sensitive lipase cDNA, and three different cell lines, designated as anti-HSL, were established. NCEH activity in anti-HSL cells was reduced to approximately 50% of that in control CHO cells. The concentration of cellular esterified cholesterol increased and the concentration of free cholesterol decreased in the anti-HSL cell lines. These results suggest that the HSL gene has a function of NCEH as well.

Expression of rac1 protein in the crypt-villus axis of rat small intestine: in reference to insulin action

The expression of rho family along the crypt-villus axis of rat small intestine was investigated. The immunoblot analysis showed that the content of rac1 protein gradually increased from tip-villus to crypt-villus enterocytes without changes in the contents of rhoA and rac2 proteins. Furthermore, the contents of rac1 protein in the entire enterocytes were markedly decreased in streptozotocin-induced diabetic rats and restored by short-term treatment with insulin. These results suggest that differentiation and proliferation in the enterocytes of rat small intestine are possibly related to the expression of rac1 protein through insulin action.

[A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in rats followed by a 5-week recovery test]

A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in Sprague-Dawley rats. Male and female rats were given the drug orally for 13 weeks at doses of 0 (control), 6, 30, 150 and 750 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted at doses of 0, 30, 150 and 750 mg/kg. Nine cases of death occurred in the 750 mg/kg group. Main pathological findings in these cases were congestion and edema in lung. Mydriasis, salivation, lacrimation and a decrease in body weight or a suppression of its weight gain were seen in the 30 mg/kg group and over. Piloerection and an increase in water consumption were seen in the 150 and 750 mg/kg groups. In addition, a decrease in spontaneous locomotor activity, abdominal distention, unkempt fur, soft stool, diarrhea and decreases in feces and food consumption were seen in the 750 mg/kg group. Ophthalmologic examination confirmed mydriasis and lacrimation in the 30 mg/kg group and over. Urinalysis showed decreases in Na+ and K+ excretions in the 30 mg/kg group and over, an increase in urinary protein in the 150 and 750 mg/kg groups, and a decrease in urine volume in the 750 mg/kg group. Hematological examination showed decreases in hemoglobin and hematocrit in the 150 and 750 mg/kg groups, and a decrease in lymphocytes in the 750 mg/kg group. Blood chemical examination showed an increase in total protein in the 30 mg/kg group and over, a decrease in triglyceride in the 150 and 750 mg/kg groups, and an increase in BUN in the 750 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy caused by hyperplasia of smooth-ER in the 30 mg/kg group and over, and a decrease in number of glycogen granules in the 150 and 750 mg/kg groups. Stimulated thyroid follicles were seen in the 30 mg/kg group and over. Increases in incidence and severity of chronic progressive nephropathy were observed in the 150 and 750 mg/kg groups. Ultrastructual features of the renal lesions were swelling and foot process loss of the glomerular epithelial cells, absorption droplets in the glomerular epithelial cells, increase of lysosomes in the proximal tubular cells and hyaline casts in the tubular lumen. Adrenocortical hypertrophy was seen in the 150 and 750 mg/kg groups. In the 750 mg/kg group, a decrease of hematopoietic tissue in bone marrow and thymic and testicular tubular atrophy were observed. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. No treatment-related effects were seen in the 6 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 6 mg/kg for 13-week oral toxicity in rats.

Two-year dietary carcinogenicity study of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in rats

The oncogenic potential of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was assessed when it was administered in the diet of Charles River Fischer-344 rats for 2 years in dosages of 0, 10, 30 and 100 mg/kg/day. No drug-related effects occurred on survival, appearance or behavior, or occurrence, location or number of palpable masses. Food efficiency and hematologic values also were apparently unaffected. Statistically significantly low mean weekly body weights and average food consumption values were observed in the all dose groups. The plasma concentrations of NS-21 and its active metabolite, RCC-36, in the treated groups were increased in a dose-dependent manner. Histopathological examinations disclosed test article-related increases in the incidence of periportal hypertrophy and midzonal hepatocellular vacuolization in the livers of the 100 mg/kg/day animals. There were no test article-related effects on the incidence or type of neoplastic lesions. In conclusion, under the conditions of this study, no oncogenic effects were evident in Fischer-344 rats when NS-21 was administered in the diet in concentrations to produce an intake of up to 100 mg/kg/day for 2 years.

Tranilast inhibits contraction and Ca2+ movement of porcine coronary arteries

In a recent clinical study, tranilast, an anti-allergic agent, was shown to reduce the rate of coronary restenosis after percutaneous transluminal coronary angioplasty, although the mechanism of this effect is unclear. The present study was undertaken to investigate the effects of tranilast on contraction and Ca2+ movement of the coronary arteries. We characterized the effects of tranilast on isometric force and aequorin-estimated intracellular Ca2+ concentrations ([Ca2+]i) of porcine coronary artery strips. Tranilast concentration-dependently (10-500 microM) inhibited histamine (3 x 10(-5) M)-induced contraction of the coronary arteries. A similar tendency was observed in the response to high K+ (30 mM) stimulation. Histamine caused phasic and tonic increases in [Ca2+]i, and high K+ caused a tonic increase in [Ca2+]i of smooth muscle, both of which were significantly suppressed in the presence of tranilast. These results suggest that tranilast inhibits the contraction of coronary arteries by inhibiting both Ca2+ influx from extracellular environment and Ca2+ release from intracellular Ca2+ stores, which might be related to its preventive effect on restenosis after coronary angioplasty.

[Oral single-dose and 13-week repeat-dose toxicity studies of RCC-36, the active metabolite of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate(NS-21), a novel drug for urinary frequency and incontinence, in rats]

Oral single-dose and 13-week repeat-dose toxicity studies of (+/-)-4-ethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride (RCC-36), an active metabolite of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, were conducted in male and female Sprague-Dawley rats. In the single-dose toxicity study, rats were given the drug at doses of 0 (control), 400, 600, 900, 1350 and 2030 mg/kg. In the 13-week repeat-dose toxicity study, rats were given the drug for 13 weeks at doses of 0 (control), 3, 30 and 300 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted. In the single-dose toxicity study, death occurred in the 600 mg/kg group and over, and LD50 values were 735 mg/kg in both sexes. The major clinical signs observed following the administration of this drug were mydriasis, salivation, decreased spontaneous locomotor activity, ataxic gait, lacrimation and urorrhea in the 400 mg/kg group and over, hypopnea and soft feces in the 600 mg/kg group and over. In addition, prone or lateral position and tonic or clonic convulsion were observed in the dead animals. Rats showed a decrease in body weight or a suppression of its weight gain in the 400 mg/kg group and over. Macroscopic findings in the dead animals were congestion in lung and retention of foamy mucinous fluid in trachea. The animals alive showed no abnormalities attributable to the treatment. In the 13-week repeat-dose toxicity study, 13 cases of death occurred in the 300 mg/kg group. Main pathological findings in these cases were congestion and edema in lung. Mydriasis was seen in the 30 mg/kg group and over. Lacrimation, salivation, wheezing, emaciation [corrected] wasting and unkempt fur were seen in the 300 mg/kg. A suppression of body weight gain and a decrease in food consumption were observed in the 300 mg/kg group. An increase in water consumption was seen in the 30 and 300 mg/kg groups. Ophthalmologic examination confirmed the mydriasis in the 30 mg/kg group and over. Urinalysis showed an increase in urine volume and a decrease in Na+ excretion in the 30 and 300 mg/kg groups and decreases in K+ and Cl- excretions in the 300 mg/kg group. Hematological examination showed decreases in hemoglobin, hematocrit, MCV and MCH, and an increase in MCHC in the 300 mg/kg group. Blood chemical examination showed decreases in triglyceride and glucose, and an increase in total protein in the 300 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy associated with hyperplasia of smooth-ER, a decrease in number of glycogen granules and an increase in number of lipofuscin in the 300 mg/kg group. Stimulated thyroid follicles were seen in the 300 mg/kg/group. In kidney, an increase in number of hyaline droplets in the proximal tubular epithelium, in which lysosomes and dense bodies were increased, was observed in the 300 mg/kg group. Dense bodies were increased also in the glomerular epithelium. In this dose group, adrenocortical hypertrophy was also observed. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. No treatment-related effects were seen in the 3 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of RCC-36 is 3 mg/kg for 13-week oral toxicity in rats.

[Toxicokinetics of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in mice and rats during 13-week dietary administration]

Toxicokinetics of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate(NS-21), a new drug for the treatment of urinary frequency and incontinence, were studied in mice and rats during a 13-week dietary administration to determine the toxicokinetic profiles of NS-21 and its active metabolite (+/-)-4-ethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride (RCC-36) in dietary carcinogenicity studies. Male and female mice were given the drug in the diet at doses of 0(control), 30, 100 and 300 mg/kg/day, and male and female rats were given the drug at doses of 0(control), 10, 30 and 100 mg/kg/day. The chosen doses and means of administration were identical to those of a 78-week dietary carcinogenicity study in mice and 2-year dietary carcinogenicity study in rats. The plasma concentrations were measured on the first and the last day of the administration. For every treatment period, the plasma concentrations of NS-21 and RCC-36 increased with dose in mice and rats. The sum of the area under the concentration-time curve(AUC) of NS-21 and RCC-36 was 2694 to 8614 ng.hr/ml in the maximum dose of mice, and 2232 to 3593 ng.hr/ml in the maximum dose of rats through the administration period. These results show that, when compared with therapeutic dose in humans(682 ng.hr/ml at 10 mg/body/day), the total maximal exposure to NS-21 and RCC-36 in the earlier dietary carcinogenicity studies were estimated to be 4 to 13 times higher in mice, and 3 to 5 times higher in rats.

[A 26-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in rats followed by a 9-week recovery test]

A 26-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in Sprague-Dawley rats. Male and female rats were given the drug orally for 26 weeks at doses of 0 (control), 5, 50 and 500 mg/kg. After discontinuation of the treatment, a 9-week recovery test was also conducted. Two cases of death occurred in the 500 mg/kg group. Mydriasis, salivation and lacrimation were seen in the 50 and 500 mg/kg groups. Alopecia, a suppression of body weight gain and an increase in water consumption were seen in the 500 mg/kg group. Food consumption measurement showed no abnormalities attributable to the treatment. Ophthalmologic examination confirmed mydriasis in the 50 and 500 mg/kg groups. Urinalysis showed an increase in urine volume in the 50 and 500 mg/kg groups, and an increase in urinary protein and decreases in Na+, K+ and Cl- excretions in the 500 mg/kg group. Hematological examination showed decreases in hemoglobin, hematocrit, MCV, MCH, MCHC and lymphocytes in the 500 mg/kg group. Blood chemical examination showed increases in total cholesterol, phospholipid and total protein and decreases in glucose, triglyceride, free T3 and T4 in the 500 mg/kg group. Measurements of liver drug-metabolizing enzymes showed an increase in T4UDP-GT activity in the 50 and 500 mg/kg groups, and an increase in cytochrome P-450 in the 500 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy caused by hyperplasia of smooth-ER in the 50 and 500 mg/kg groups, and a decrease in number of glycogen granules in the 500 mg/kg group. Stimulated thyroid follicles were seen in the 50 and 500 mg/kg groups. Increases in incidence and severity of chronic progressive nephropathy were also observed in the 500 mg/kg group. In this dose group, adrenocortical hypertrophy was also observed. The recovery test showed that the above-mentioned changes were satisfactorily reversible. The serum concentrations of NS-21 and its active metabolite, RCC-36, in the treated groups were increased in a dose-dependent manner. No treatment-related effects were seen in the 5 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 5 mg/kg for 26-week oral toxicity in rats.

[A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in dogs followed by a 5-week recovery test]

A 13-week oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in beagle dogs. Male and female dogs were given the drug orally for 13 weeks at doses of 0 (control), 5, 25 and 125 mg/kg. After discontinuation of the treatment, a 5-week recovery test was also conducted. No effects related to the treatment were observed on survival. Mydriasis and a decrease in body weight or a suppression of its weight gain were seen in the 25 and 125 mg/kg groups. Vomiting, salivation and a decrease in food consumption were seen in the 125 mg/kg group. Ophthalmologic examination confirmed the mydriasis in the 125 mg/kg group. Electrocardiographic examination and urinalysis showed no abnormalities attributable to the treatment. Hematological examination showed an increase in number of platelets in the 125 mg/kg group. Blood chemical examination revealed increases in GPT and ALP and a decrease in albumin in the 25 and 125 mg/kg groups, and an increase in triglyceride in the 125 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy in the 125 mg/kg group, hyperplasia of smooth-ER and concentric lamellar bodies derived from the smooth-ER, and bile pigments in the bile capillary, hepatocyte and stellate cells of Kupffer in the 25 and 125 mg/kg groups. Megakaryocytes in mesenteric lymph node were observed in the 25 and 125 mg/kg groups. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. No treatment-related effects were seen in the 5 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 5 mg/kg for 13-week oral toxicity in dogs.

[A 12-month oral repeated dose toxicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in dogs followed by a 2-month recovery test]

A 12-month oral repeated dose toxicity study of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was conducted in beagle dogs. Male and female dogs were given the drug orally for 12 months at doses of 0 (control), 3, 17.5 and 100 mg/kg. After discontinuation of the treatment, a 2-month recovery test was also conducted. No effects related to the treatment were observed on survival and water consumption. Mydriasis, vomiting and a decrease in body weight or a suppression of its weight gain were seen in the 17.5 and 100 mg/kg groups. Salivation and a decrease in food consumption were seen in the 100 mg/kg group. Ophthalmologic examination confirmed the mydriasis in the 17.5 and 100 mg/kg groups. Electrocardiographic and hematological examinations and urinalysis showed no abnormalities attributable to the treatment. Blood chemical examination revealed increases in GPT and ALP in the 17.5 and 100 mg/kg groups, increases in GOT and triglyceride and a decrease in total protein in the 100 mg/kg group. Pathological examination disclosed hepatocellular hypertrophy and concentric lamellar bodies derived from the smooth-ER in the 100 mg/kg group, and hyperplasia of smooth-ER, an increase in number of lysosomes and bile pigments in the bile capillary, hepatocyte and stellate cells of Kupffer in the 17.5 and 100 mg/kg groups. The recovery test showed that the above-mentioned changes were satisfactorily reversible or the degree and frequency of these changes were lowered. The serum concentrations of NS-21 and its active metabolite. RCC-36, in the treated groups were increased in a dose-dependent manner. No treatment-related effects were seen in the 3 mg/kg group. These results show that the NOAEL (no observed adverse effect level) of NS-21 is 3 mg/kg for 12-month oral toxicity in dogs.

Seventy-eight-week dietary carcinogenicity study of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a novel drug for urinary frequency and incontinence, in mice

The oncogenic potential of (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, was assessed when it was administered in the diet of Charles River B6C3F1 mice for 78 weeks in dosages of 0, 30, 100 and 300 mg/kg/day. No drug-related effects occurred on survival, appearance or behavior, or occurrence, location or number of palpable masses. Average food consumption, food efficiency and hematologic values also were apparently unaffected. Statistically significantly low body weights were observed in the 100 and 300 mg/kg/day mice. The plasma concentrations of NS-21 and its active metabolite, RCC-36, in the treated groups were increased in a dose-dependent manner. Histopathological examinations disclosed midzonal hepatocellular vacuolization compatible with lipid vacuoles in both sexes at the 300 mg/kg/day dose level. There were no test article-related effects on the incidence or type of neoplastic lesions. In conclusion, under the conditions of this study, no oncogenic effects were evident in B6C3F1 mice when NS-21 was administered in the diet in concentrations to produce an intake of up to 300 mg/kg/day for 78 weeks.

[The mechanism of increased thyroidal function caused by (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate(NS-21), a novel drug for urinary frequency and incontinence, administration in rats]

A study was conducted to elucidate the mechanism of the increased thyroidal function caused by oral administration of (+/-)-4-diethylamino-1, 1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate (NS-21), a new drug for the treatment of urinary frequency and incontinence, in rats. Rats were given 500 mg/kg of NS-21 orally for 13 weeks. Rats were also given 500 mg/kg of the drug and 15 micrograms/animal of thyroxine (T4) in order to assess the influence of T4 treatment. NS-21 caused decreases in both total and free T4 and increases in TSH and thyroxine uridine diphosphate glucuronyltransferase (T4UDP-GT). Morphological examination of thyroid gland revealed stimulated follicles indicating heightened thyroidal function. The treatment of T4 inhibited the stimulating effect of NS-21 on thyroid gland. These results show that the administration of NS-21 caused induction of T4UDP-GT, which resulted in a compensatory stimulation of the thyroidal function by the increased secretion of pituitary TSH in response to increased blood thyroid hormone metabolism.

Early appearance of abnormality of microperoxisomal enzymes in the cerebral cortex of senescence-accelerated mouse

SAMP8, a substrain of senescence-accelerated mouse (SAM), has been characterized by several age-related deficits in the brain. Previously, we reported that the contents of lipid peroxides and protein carbonyl, and net generation of H2O2 were increased in the cerebral cortex of SAMP8 at 4-8 weeks of age in comparison with those in age-matched SAMR1 substrain used as a control. To study the cause of these increases, we compared the activities of antioxidative enzymes in the cerebral cortex between the two substrains. The catalase activity was decreased by 75% in SAMP8 at 4-8 weeks of age, whereas neither superoxide dismutase nor glutathione peroxidase activities were changed. The change in the catalase activity was seen only in the cerebral cortex where oxidative stress was increased in SAMP8. On the contrary, the activity of acyl-CoA oxidase, a microperoxisomal H2O2-producing enzyme, in the cerebral cortex of SAMP8 was increased 1.6 fold in comparison with that in age-matched SAMR1 without change in the activity of D-amino acid oxidase. Furthermore, the changes in the activities of catalase and acyl-CoA oxidase with age were paralleled with those observed in oxidative stress in SAMP8. These results suggest that the abnormality of activities in two microperoxisomal enzymes, catalase and acyl-CoA oxidase, may be one of the cause of the early increase in oxidative stress observed in the cerebral cortex of 4-8 weeks old SAMP8.