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Biomedical subjects

M Tsuchitani

Publications and source records attributed to M Tsuchitani.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cadmium-induced osteomalacic and osteopetrotic lesions in ovariectomized rats.

The effects of long-term administration of cadmium (Cd) chloride on the bone were studied using ovariectomized rats. The rats were injected iv with the compound at doses of 1.0 and 2.0 mg/kg, 5 days a week, for 13 weeks. The serum concentrations of calcium and inorganic phosphorus were significantly increased from 8 weeks in the 2.0 mg/kg group. The bone Cd content was gradually increased for 13 weeks in a dose-dependent manner. Calcium and phosphorus contents in the bone, and serum levels of parathyroid hormone and osteocalcin, were not significantly different between Cd-treated and control rats. Histopathologically, chronic Cd nephropathy such as tubular atrophy and interstitial fibrosis was observed with clinical polyuria and increased enzymuria. The skeletal changes were detected mainly in the femur and tibia. In the metaphysis of Cd-treated rats, cancellous bone mass increased with time. This change was detected as an increased opacity by a roentgenogram. In the cortical bone of the midshaft haversian canals were dilated with clearly bordered osteoid seams and showed a motheaten pattern in rats in the 2.0 mg/kg group at 13 weeks. In the present study, we report Cd nephropathy and osteomalacic changes in ovariectomized rats with iv injection of CdCl2 for 13 weeks. Although an involvement of the indirect action of Cd through renal failure could not be ruled out in this experiment, our biochemical and pathological data suggested that osteomalacia was induced by a direct action of Cd on the bone through abnormal calcium homeostasis.

Animals↗
PubMed1993

Ovariectomy enhances cadmium-induced nephrotoxicity and hepatotoxicity in rats.

The toxicity of cadmium (Cd) chloride was studied in ovariectomized (OX) female rats and non-OX female rats after intravenous administration of the compound at doses of 2.0 and 3.0 mg/kg for 14 days. Mild hypochromic microcytic anemia developed in all rats treated with Cd, but growth retardation in the OX rats was more prominent than that in the non-OX rats. There was an increase of AST and ALT and a decrease of total cholesterol and the A/G ratio in both OX and non-OX rats treated with Cd. The hepatic and renal Cd concentrations increased in a dose-dependent manner, and the concentrations in both organs on Day 14 were comparable in the 3.0 mg/kg OX group (liver, 270.0 +/- 39.6 micrograms/g; kidney, 121.3 +/- 10.1 micrograms/g) and non-OX group (liver, 277.0 +/- 29.9 micrograms/g; kidney, 100.8 +/- 1.3 micrograms/g). Hepatocyte necrosis developed only in OX rats treated with Cd, and the nephrotoxicity of Cd was also notably enhanced by ovariectomy, since Cd nephropathy affected the proximal convoluted epithelium more severely and more frequently in OX rats than in non-OX rats. BrdU-labeled cells in the renal cortex were increased by approximately 2.7-fold in OX rat (7.4 cells/mm2) over those in the renal cortex in non-OX rat (2.7 cells/mm2). In conclusion, the present study demonstrated that ovariectomy enhanced Cd-induced nephrotoxicity and hepatotoxicity in rats.

Animals↗
PubMed1993

Granule cell type cerebellar hypoplasia in a beagle dog.

Cerebellar hypoplasia characterized by severe depletion of granule cells and almost intact Purkinje cells was found in a male 19-month-old beagle dog used in a toxicity study. Microscopically, there was a narrow space lacking granule cells between the row of Purkinje cells and the medulla. Gliosis was not seen in any portion of the cerebellum including this space. No significant changes were seen in the Purkinje cells except for occasional cytoplasmic vacuolation. In the molecular layer and medulla, no histopathological abnormalities were observed.

Animals↗
PubMed1992

Endocrine cell populations in the pancreas of diabetic WBN/Kob rats.

Numerical changes of insulin-, glucagon- and somatostatin-positive cells in the pancreas of WBN/Kob male rats with spontaneously occurring diabetes were examined. The rats examined were divided into three different age groups: Groups I (12 weeks old) and II (33 weeks old) were clinically prediabetic and group III (60-90 weeks old) was diabetic. Serum glucose value was in the normal range in groups I and II, while it was much higher in group III. B and A cells were markedly decreased in number in groups II and III. In group II, the ratio of B to A cells was normally preserved, though the total endocrine cell number was markedly decreased as compared with that in group I. In group III, the percentage of B cells was decreased significantly. The normal ratio in group II seemed to keep serum glucose within the normal level. In addition to the total endocrine cell reduction, an altered ratio of B and A cells was considered to cause the diabetic condition.

Animals↗
PubMed1992

[Effect of sex hormones on the onset of diabetic syndrome in WBN/Kob rats].

The effects of sex hormone on diabetic conditions were investigated in WBN/Kob strain rats, i.e., castrated or spayed, hormone-treated, and non-treated rats. The effects of sex hormone on glycosuria, body-weight change, glucose tolerance and histopathology of the pancreas were compared among these animals. There were no abnormal changes in these parameters in the non-treated females and estrogen-treated males. The glycosuria began to be observed from the age of about 30 weeks in the non-treated group and from the age of 52 weeks in the castrated group. In the female animals, this symptom began to appear from the age of 55 weeks in the testosterone-treated group and from the age of 72 weeks in the spayed group. Before the onset of the diabetic symptoms, glucose tolerance was impaired in these animals. Body weights of the castrated and estrogen-treated males were lower than that of the non-treated males, especially in the estrogen-treated males. Those of the spayed and testosterone-treated females were much heavier than that of the non-treated females. Testosterone treatment accelerated body-weight gain in the spayed female animals. Histopathological examination of the pancreas revealed atrophy of the aciner tissue and atrophy and disappearance of the islet cells similar to those of the non-treated WBN/Kob male rats in the castrated males, spayed females and testosterone-treated females. However, these changes were not observed in the non-treated females or estrogen-treated males. These findings suggest that female hormone suppressed the onset of hyperglycemia along with glycosuria and male hormone accelerates the onset of hyperglycemia in the WBN/Kob rats.

Animals↗
PubMed1991

Glomerular lesions in spontaneously occurring diabetic WBN/Kob rats.

Glomerular lesions in WBN/Kob male rats with spontaneous diabetes were examined histopathologically. The glomerulopathy caused by diabetes was compared with lesions in chronic progressive nephropathy of non-diabetic SD and F344 male aged rats. Diffuse and global thickening of the mesangial area was observed only in WBN/Kob rats and showed a statistically significant correlation with serum glucose concentrations. Therefore, it suggested that the mesangial thickening was a result of hyperglycaemia. Fibrin cap-like lesions were seen in both WBN/Kob and non-diabetic SD or F344 male rats. The severity of these lesions was closely related to that of chronic progressive nephropathy and, therefore, the fibrin cap-like lesions were considered to be due to the chronic progressive nephropathy.

Age Factors↗
PubMed1990

Glycogen accumulation in the renal tubular cells of spontaneously occurring diabetic WBN/Kob rats.

Cytoplasmic and nuclear accumulation of glycogen granules in the kidney cells of 72 male WBN/Kob rats with a long-term diabetic condition was studied histologically and by electron microscopy. The incidence and degree of the accumulation showed good correlation with the blood glucose concentration. In the kidneys, there was evidence of two types of lesion, cytoplasmic glycogen accumulation in the distal convoluted tubules and nuclear accumulation in the ascending thick segment of Henle's loops. Electron microscopically, the cytoplasmic glycogen accumulation was often associated with an increased number of lysosomal bodies containing lamellar bodies. Glycogen bodies, the halo of which was thought to be identical with that of nuclear bodies, were frequently observed in the nuclei containing the glycogen granules. These morphological and topographical differences between the two types of lesion were considered suggestive of different pathogenetic mechanisms for glycogen accumulation in the kidney cells.

Animals↗
PubMed1990

Superficial eosinophilic gastritis in laboratory beagle dogs attributable probably to diet.

Stomach tissues from 222 beagle dogs, which were used for toxicological studies, were examined histopathologically. Out of 190 dogs fed the same diet, 185 had gastric lesions, whereas all of 32 dogs fed another diet were free from them. The gastric lesions were noted as an accumulation of eosinophils, infiltration of inflammatory cells including lymphocytes, plasma cells and histiocytes in the gastric lamina propria, formation of foreign body type multinucleated giant cells, focal desquamation and papillary proliferation of mucosal epithelium. The lesions were confined to the superficial layer of the antral and pyloric mucosa, and neither desmoplasia nor clinical signs were seen. Multinucleated giant cells often contained amphophilic foreign bodies of varying appearance with inconsistent reaction for periodic acid-Schiff (PAS), but no definite causal agents were detected.

Animals↗
PubMed1989

Accumulation of pigment granules in lacrymal gland epithelium in practolol-treated beagle dogs.

A 6-month oral toxicity test of practolol was carried out in beagle dogs as a reference control for a newly developed beta blocker. No significant drug-induced changes were detected in any animals by various ophthalmological examinations such as ERG, tear flow, lysozymal activity in tears, etc. However, an unusual pathological change was detected in the lacrymal gland of all five dogs treated with practolol and not in control animals. Macroscopically, the lacrymal glands assumed a blackish brown to deep black colour on both the outside and the cut surface. Microscopically, fine, dark-brown pigment granules were present in the apical and supra-nuclear portion of the cytoplasm of predominantly serosal type epithelial cells. These pigments reacted positively to Schmorl's method for lipofuscin, but gave a negative PAS reaction for polysaccharide, Prussian blue for iron and Ziehl-Neelsen method for ceroid pigment. They were detected as membrane-bound electron-dense bodies by electron microscopy. Similar pigments were also deposited in the cytoplasm of the apocrine sweat gland. Although the mechanism of the accumulation of these granules is far from clear, concentration of practolol in the lacrymal gland is considered to be very closely related to the presence of these granules. A possible mechanism for ocular toxicity by practolol, involving this change, is discussed.

Animals↗
PubMed1989

[One-year chronic oral toxicity study of propiverine hydrochloride in dogs followed by one-month recovery].

The chronic oral toxicity of propiverine hydrochloride (P-4), a new anti-pollakiuria agent, was studied in beagle dogs. Groups of 6 males and 6 females were treated with P-4 at doses of 0, 0.3, 1, 3, 9 mg/kg/day for one year and thereafter 2 animals of both sexes in each group were placed on withdrawal for one month. During administration and recovery period, no death occurred in any dosed animals. As a toxic sign, only the frequency of vomiting was increased in animals of 1, 3 and 9 mg/kg/day groups. Body weight, food and water consumption were not affected by the P-4 administration. In serum chemical examinations, gamma-GTP activity was increased in both sexes of 9 mg/kg/day group at 6 month of administration. Further decrease in total and free cholesterol, triglyceride and phospholipid, increase in GPT activity were detected in some animals of 9 mg/kg/day group at 12 month of administration. In addition decreasing tendency in levels of albumin was noted in males of 9 mg/kg/day group at 9 and 12 month of administration. And also, a gradual increase in total protein level and a gradual decrease in alkaline phosphatase activity were seen in control group, but in females or males of 9 mg/kg/day group, those changes were mild. Urine pH rised slightly in females of 3 mg/kg/day group and in both sexes of 9 mg/kg/day group. No specific findings attributable to P-4 treatment were detected in ECG, heart rate, funduscopy, hematology, fecal occult blood test and necropsy. The absolute and/or relative liver weight in males of 3 and 9 mg/kg/day groups were significantly increased. Light-microscopically, the hypertrophy of hepatocytes characterized by homogenization and enlargement of cytoplasmic space, and concentric inclusions in hepatocytic cytoplasm were detected in both sexes of 3 and 9 mg/kg/day groups. Corresponding to these microscopical findings, the following changes were observed electron-microscopically, the proliferation of smooth surfaced endoplasmic reticulum in hepatocytes in both sexes of 1, 3 and 9 mg/kg/day groups, lamellar bodies in hepatocytes in females of 3 mg/kg/day group, and in both sexes of 9 mg/kg/day group, and annulate lamellae in hepatocytes were detected in one female of 9 mg/kg/day group. After the recovery period, the above mentioned abnormalities were markedly attenuated or disappeared except the changes in hepatocytes. From these results, it seemed that 9 mg/kg/day of P-4 might be safety dose.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗
PubMed1988

[Retinal degeneration in the WBN/Kob rat].

Spontaneous, retinal degeneration in the WBN/Kob rat, a new diabetic strain, was examined by behavior pattern, electroretinogram (ERG) and histopathology. Histopathological evidence of retinal degeneration was first detected at about 30 weeks of age in male and female rats. The earliest change in the retina was loss of rads and cones, and the inner layer was gradually involved. The retina showed marked atrophy in the thinned inner plexiform layer and a decreased number of ganglionic cells by 90 weeks. Severe retinal change was observed in almost all rats over 90 weeks old. Prior to the onset of histological change, the ERG showed prominent change. Amplitude of a- and b-waves began to be reduced at 17 weeks and was non-recordable at 32 weeks. This retinal abnormality was thought to be hereditary, but further investigation is needed to clarify the relationship between the genetic background of this change and diabetes.

Animals↗
PubMed1988

[Effect of gonadectomy on the onset of diabetic syndrome in the female WBN/Kob rats].

Almost all the male animals of WBN/Kob rat strain show the diabetic syndrome whereas none of the female animals develop such diseased conditions even at elder age. We investigated the effect of sex hormones on the onset of diabetic syndrome of this rat strain by comparing the results of body weight gain and various clinical tests such as glucose tolerance, serum biochemistry and histopathology of spayed female rats with those of non-treated and sham-operated female animals kept until 88-week-old. Non-treated and sham-operated female animals had shown no abnormal result even at 88-week-old. Spayed female animals began to reveal glucosuria associated with polydipsia and polyuria from 72-week-old, and gradually developed emaciation and cataract. Increased body weight gain, impaired glucose tolerance and lasting hyperglycemia were observed prior to the onset of the symptoms. Pancreatic changes consisted of atrophy of acinar tissue and atrophy or disappearance of islet tissue attributable to clinical data also were detected in spayed female animals. These diabetic syndrome and pancreatic change were analogous to those of aged male WBN/Kob rats but the onset of spayed females was delayed and less severe. Present results suggest that female sex hormones are protective from the onset of diabetic syndrome of WBN/Kob rats.

Animals↗
PubMed1988

[Six-month chronic intravenous toxicity study of cefodizime sodium in dogs].

The chronic intravenous toxicity of cefodizime sodium (THR-221) was studied in beagle dogs. Groups of 6 males and 6 females were treated with THR-221 at doses of 0 (saline), 200, 400, 800 and 1600 mg/kg/day for 6 months. The THR-221 related symptoms were vomiting, excessive drinking behavior and salivation. The paleness of the visible mucosa and discoloration of vascular color by funduscopy due to systemic anemia were observed in one animal each of 800 and 1600 mg/kg/day groups. Body weight was depressed transiently or continuously in a few animals of 400-1600 mg/kg/day groups. The hematological, serum chemical and urinalysis findings in a few animals of 400-1600 mg/kg/day groups revealed decreases in RBC count, PCV and hemoglobin, an increase in reticulocyte count, a decrease in WBC count, a decrease in platelet count, slight increase in TP, and albumin, a decrease in AlP, and an increase in urinary Na. Light microscopically, deposition of hemosiderin and increased extramedullary hematopoiesis in the liver and spleen, and deposition of fibroid substance in the white pulp of the spleen and diffuse fibrosis in the bone marrows were detected in a few animals of 800 and 1600 mg/kg/day groups. Electron microscopically, no significant toxic changes were observed. The maximum nontoxic doses of THR-221 are estimated as 200 mg/kg/day in male and less than 200 mg/kg/day in female.

Anemia↗