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Biomedical subjects

E Ogata

Publications and source records attributed to E Ogata.

At least 343 records · Page 19Linked to original sources

Lupus-like syndrome--a rare complication in thionamide treatment for Graves' disease.

A patient with Graves' disease who experienced various allergic reactions to both PTU and MMI is reported. She developed fever, skin rash, lymphadenopathy, liver damage and moderate leukopenia during PTU administration. Furthermore, she developed an MMI-induced lupus-like syndrome characterized by generalized lymphadenopathy, migrating, polyarthritis and myalgia, and results of tests for anti-DNA antibody and anti-nuclear antibody, and LE were positive. All these abnormalities reverted to normal upon discontinuation of medication after subtotal thyroidectomy.

Adult↗

Inhibitory effect on calcium channel blockers on alpha -adrenergic activation of glycogenolysis and calcium efflux in perfused rat liver.

In an attempt to verify the importance of calcium ions in mediating alpha -adrenergic stimulation, the effects of a calcium channel blocker, verapamil, on phenylephrine-induced glycogenolysis and calcium efflux in perfused livers prepared from fed rats were determined. The blocker inhibited phenylephrine-induced glycogenolysis in a noncompetitive and dose-dependent manner between 50 micro M and 500 micro M. However, it did not affect 2, 4-dinitrophenol-induced glycogenolysis. It had no significant effect on 45 Ca uptake by the perfused liver, but inhibited basal as well as phenylephrine-induced efflux of 45Ca from 45Ca-loaded liver. The inhibitory effects on basal 45Ca release and phenylephrine-induced glycogenolysis and 45Ca released correlated very well. All the the effects of verapamil were reproduced by another calcium channel blocker, diltiazem, suggesting that these effects are common to a variety of calcium channel blockers. These results indicate that the process of calcium influx and the function of phosphorylase per se are not directly involved in the inhibitory action of the blocker. Although it is possible that verapamil interferes with binding of the alpha -adrenergic agonist to the plasma membrane, the good correlation between the inhibitory effects of verapamil on basal 45Ca released and on phenylephrine-induced release of 45Ca suggests another mechanism, involving calcium ions. The blocker appears to inhibit the glycogen phosphorylase activity induced by phenylephrine via a cell-membrane mechanism in which calcium ion flux changes are intimately involved.

Animals↗

["Hormone receptor diseases" in Japan: A nation-wide survey for testicular feminization syndrome, pseudohypoparathyroidism, nephrogenic diabetes insipidus, Bartter's syndrome and congenital adrenocortical unresponsiveness to ACTH (author's transl)].

A nation-wide survey for five "hormone receptor diseases" was carried out. For the first survey, an inquiry was sent to all hospitals in Japan having more than 200 beds, in order to determine how many patients there were between 1968-1977. A further detailed survey was carried out on patients who were reported in the first survey. The approximate numbers of patients in Japan estimated from these surveys are the following: testicular feminization syndrome (TFS), 390; pseudohypoparathyroidism (PHP), 220, nephrogenic diabetes insipidus (NDI), 280; Bartter's syndrome, 90; congenital adrenocortical unresponsiveness to ACTH (CAUA), 18. In 73 cases of TFS, partial virilization was observed in 23% (the incomplete form). Testes were found in all cases and the epididymis in 84%, whereas none of the patients had seminal vesicles. PHP consisted of 38 Type-I cases, 6 Type-II cases and 25 unclassified cases. There were 27 males and 42 females. Skeletal anomalies were found in two-thirds of the patients. Grades of hypocalcemia and soft tissue calcification were more prominent in Type I. After treatment, none of the Type-I patients showed normal urinary cyclic AMP response to parathormone, although urinary phosphate response was normalized in one and markedly improved in 4. In 78 patients with NDI, there were 67 males and 11 females. The age of the onset of NDI ranged from 0 to over 50, but 22 out of 29 cases of hereditary NDI had the onset at age 0. There seemed to be at least two subtypes; one beginning in the neonatal period or early childhood, and the other having the onset in late childhood or adult. The important initial symptoms were fever and anorexia in the early onset type. Growth retardation was remarkable in early childhood. Diuretics were effective in most of the cases. There were 22 male and 12 female patients with Bartter's syndrome. Indomethacin was effective in 9 out of 10 patients studied.

Adolescent↗

Actomyosin extracted from bovine aortic intima.

Actomyosin extracted from bovine aortic intima with a KCl-ATP medium of low ionic strength, but not with a KCl medium of high ionic strength, exhibited Ca2+ sensitivity. Aortic medial actomyosin extracted with a medium of high ionic strength retained the Ca2+ sensitivity. These differences in extractability suggest that actomyosin of the aortic intima is different from that of the aortic media.

Actomyosin↗

Diurnal changes in calcium and phosphate metabolism in rats.

Diurnal changes in the metabolism of calcium and phosphate were studied in fasted conscious rats by use of a perfusion balance study method. On a light dark 12:12 h schedule and on a constant iv load of calcium among other nutrients, the animals exhibited a diurnal rhythm in which urinary excretion of calcium was low in the night and high in the day. This was accompanied by a reciprocal change in phosphate balance (high excretion in the night, and low in the day). The diurnal change was abolished by adrenalectomy. Thyroparathyroidectomy alone did not prevent the diurnal change. It was abolished, however, when thyroparathyroidectomy was followed by a constant infusion of parathyroid hormone (0.8 U/h). These data indicate the presence of a diurnal rhythm of calcium and phosphate metabolism in rats and the involvement of parathyroid and adrenal hormones in the genesis of the rhythms.

Animals↗

Enhancement by thyroid hormone of free and bound RNA polymerase IB activities in rat liver nucleoli.

After having defined reliable assay conditions for free and template-bound RNA polymerase I activities, we examined in detail the effect of thyroid hormone in vivo on nucleolar RNA polymerase I in rat liver. The enzyme activity decreased markedly in the hypothyroid state produced by either thyroidectomy, hypophysectomy or by administration of propylthiouracil (PTU). One large dose (25 microgram/100 g body weight) of T3 given intraperitoneally caused a rapid recovery of the enzyme activity within 24 h either in the presence or absence of the pituitary. The enzyme activity of both free and chromatin-bound enzyme changed in parallel throughout. A similar recovery was noted after daily subcutaneous injections of a physiological dose (1 microgram/100 g body weight) of T3 for about 3 weeks. Analyses of subfractions of the enzyme indicated that only IB-type enzyme (the enzyme fraction containing the whole set of subunits) changed in response to thyroid hormone action, also irrespective of the presence or absence of the pituitary. The possibility that thyroid hormone is a major physiological regulator of the synthesis of RNA polymerase I in rat liver is discussed.

Animals↗

High-fiber diet in the control of diabetes in rats.

The effects of high-fiber diet on the metabolic states in streptozotocin-induced diabetic rats were investigated. The animals were divided into three groups: group A fed on a diet containing 5% of fiber (bagasse), group B paired-fed on a control diet and group C fed on a control diet ad libitum. The body weight gain was greater and the fasting blood sugar level was lower in A than B and C. The plasma triglyceride level was lowest in A, while no significant difference in the serum total cholesterol level was observed between A and B. Plasma glucagon levels were decreased in A and increased significantly in B and C. Plasma insulin levels were not changed in these groups. These results support the theory that a high-fiber diet is an effective therapeutic regimen for the control of metabolic derangement in diabetics.

Animals↗

A case of primary hyperparathyroidism with low serum alkaline phosphatase levels.

A 23-year-old man with primary hyperparathyroidism which was typical except for reduced alkaline phosphatase activity is reported. Histological examination of surgical specimens revealed chief cell hyperplasia of the parathyroid glands. Systemic abnormalities of alkaline phosphatase were demonstrated, i.e., marked reduction of all isoenzymes and undetectable osseous enzyme in the serum, abnormal distribution of the enzyme in hepatocytes and diminished enzyme activities in leukocytes. In addition, diminished bone remodeling activity was revealed in a biopsy specimen of the rib. The association of hypophosphatasia is highly unlikely, because of normal urinary excretion of phosphoethanolamine, lack of osteomalacia, and no indication of an hereditary factor. The causal relationship between low remodeling activity and abnormalities in alkaline phosphatase was suggested.

Adult↗

A decreased response of cyclic adenosine monophosphate concentrations to glucagon in liver slices from streptozotocin-induced diabetic rats.

Responses to glucagon from the adenylate cyclasecyclic adenosine monophosphate (cAMP) system in liver slices from control and streptozotocin-induced diabetic rats were compared. Tissue cAMP levels were similar in the basal state but responded poorly to glucagon (20 pg/ml-2 microgram/ml) in diabetic rats. Insulin treatment of diabetic rats in vivo led to a reversal of the glucagon stimulation towards the values in the control rats. The basal and glucagon-stimulated activities of adenylate cyclase in crude membrane fractions were similar in both groups. Plasma immunoreactive glucagon levels in diabetic rats were approximately three times higher than those in normal rats. Liver slices obtained from normal rats, which were injected with glucagon (0.2 mg, i.m.) 45 min previously, also showed an impaired responsiveness to glucagon of tissue cAMP levels, while no significant difference in adenylate cyclase activity was observed between the normal and glucagon-treated rats. These results suggest that the responsiveness of liver slices from the streptozotocin-induced diabetic rat has been modified by the preceding hyperglucagonemia. The reason for the observed differences between slices and crude membranes is not known.

Animals↗

Salmon calcitonin-induced stimulation of 1 alpha,25-dihydroxycholecalciferol synthesis in rats involving a mechanism independent of adenosine 3':5'-cyclic monophosphate.

The effect of natural salmon calcitonin on accumulation in plasma of 1 alpha,25-dihydroxy-[3H]cholecalciferol from 25-hydroxy[3H]cholecalciferol in vivo was investigated in vitamin D-deficient thyroparathyroidectomized rats into which graded doses of the hormone were continuously infused by use of a balance study system. A dose-dependent increase in plasma concentrations of 1 alpha,25-dihydroxy[3H]cholecalciferol was observed with calcitonin infusion for 6--30h at a rate greater than 20 M.R.C. m-units/h. Infusion of parathyrin or cyclic AMP produced a similar stimulation [Horiuchi, Suda, Takahashi, Shimazawa & Ogata (1977) Endocrinoly 101, 969--974], but the maximal effect of calcitonin was additive to that of either parathyrin or cyclic AMP. Furthermore concurrent infusion of theophylline (0.5 mumol/h) did not potentiate the effect of submaximal doses (3 and 20 M.R.C. m-units/h) of calcitonin. Plasma concentrations of calcium showed a decrease with calcitonin infusion for 30h, but those of Pi remained unchanged. These results strongly suggest that the rat kidney is endowed with a calcitonin-sensitive 1 alpha-hydroxylase system that is separate from the parathyrin/cyclic AMP system and is independent of changes in plasma Pi.

Animals↗