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Biomedical subjects

S Tojo

Publications and source records attributed to S Tojo.

At least 127 records · Page 7Linked to original sources
PubMed1980

Inhibitory effect of progesterone on follicular growth and induced superovulation in the rat.

We investigated the effect of exogenous progesterone on follicular growth and pregnant mares' serum gonadotropin and human chorionic gonadotropin (PMS-HCG) induced superovulation in intact and hypophysectomized immature rats. Although the administration of progesterone during PMS-HCG injections had no effect on superovulation, the administration of progesterone beginning 3 days before PMS injection inhibited superovulation in both intact and hypophysectomized rats. In order to study the mechanism of inhibition of superovulation by pretreatment with progesterone, an autoradiographic study using tritiated thymidine was done in hypophysectomized rats just before PMS injection. The labelling indices of granulosa cells were significantly decreased by the administration of progesterone (p < 0.001). Treatment with progesterone resulted in an increase of the follicles in early stages of atresia with pycnotic nuclei in granulosa cells surrounding apparently normal oocytes. Ovarian histology and serum and ovarian tissue concentrations of estradiol were then examined in hypophysectomized rats 20 h after HCG injection. Large Graafian follicles and corpora lutea were rarely seen in rats previously given progesterone, whereas many large Graafian follicles and corpora lutea were observed in the control rats. The concentrations of estradiol in the progesterone-pretreated rats were significantly reduced in serum (p < 0.02) and slightly reduced in ovarian tissues when compared with controls.

Animals↗
PubMed1980

[Effect of human chorionic somatomammotropin on release of glucose by perfused rat liver (author's transl)].

The biological action of hCS was studied in non-recirculating perfusion system of the pregnant rat liver. A modified method of Mortimore and of Millor for the liver perfusion was used. The perfusate was prepared with Krebs-Ringer bicarbonate buffer with the addition of BSA (2%), glucose (10 mM) and human erythrocytes (Ht. 12%). The results were as follows. 1) The biological condition of the liver remained good during 90 minutes of perfusion as judged by its gross appearance, O2 consumption, CO2 production, bile secretion and the levels of transaminase, K+, pH in effluent and the microscopic observation after the perfusion. 2) An addition of hCS (20 micrograms/ml) to the perfused pregnant liver resulted in a momentary increase of glucose, FFA and K+ concentration in the effluent. 3) The elevation of the glucose level was also observed after the repeated administration of hCS. This release of glucose from perfused liver after hCS administration took, place more rapidly with the progress of the pregnancy. 4) The elevation of glucose level was maintained longer by the continuous administration of hCS (10 micrograms/ml). 5) Hepatic glycogen decreased after the continuous administration of hCS, but it increased in the control group. The level of cyclic-AMP in the perfused liver rose after the continuous administration of hCS.

Animals↗
PubMed1980

[Renin and aldosterone during pregnancy (author's transl)].

Systematical determination of renin activity (PRA) and aldosterone concentration (PA) in blood of normal and hypertensive pregnant women was done. At the same time, reactive change of PRA and PA to NaCl loading was studied, and the authors gained the following conclusions: 1) In normal pregnant women a significant increase was observed respectively in PRA and PA in comparison with those observed in non-pregnant status (PRA: P less than 0.05, PA: P less than 0.02). A peak (11.85 ng/ml/hr) was formed in PRA at the 32nd week of pregnancy, while in PA an increase lasted until the start of labour, attaining a level of 563.3 pg/ml (mean value). 2) PRA and PA in toxemia of pregnancy were obviously lower in comparison with normal pregnancy in the corresponding period. Analysis by the two dimensional cordinate system in which PA value was represented by axis of abscissas and PRA value by axis of ordinate disclosed that hypertensive toxemia of pregnancy tended to be distributed among patients with low PRA while non-hypertensive toxemia of pregnancy was distributed among patients with low PA. 3) In non-pregnant women and those in the first trimester, no noticeable change was displayed by NaCl load either in PRA or in PA, but the reactivity became obvious along with advancement of pregnancy and a high reactivity was shown by pregnant women who were positive in the so-called roll-over test. Also when women whose blood pressure rose to 140/90 mmHg or above after NaCl loading were classified as those positive in NaCl loading test, all the normal pregnant women were negative, but among the patients with hypertensive pregnancy, a positive reaction was represented in half of them in spite of the treatment. The above signifies that the PRA and PA were different in their behaviors in the third trimester, and in the value of PA, participation of aldosterone deriving from fetus was suggested. Analysis of PRA and PA by the two dimensional cordinate system and analysis of the behavioral reaction in NaCl loading test were supposed to be clinically useful for classification of the clinico-pathological types of toxemia of pregnancy.

Adult↗
PubMed1979

Immunohistochemical interaction on antisera to HCG and its subunits with chorionic tissue of early gestation.

Immunohistochemical localization of hCG and its subunits in chorionic tissue of early gestation was carried out. Antibodies to purified hCG and its subunits were obtained by using these agents for immunization according to the small doses method. The antibody titers and specificities were examined by B/T and standard curves in homologous radioimmunoassay system. The tissue preparations were stained both by a direct and by an indirect method utilizing these antisera and observing the specimens under a fluorescent microscope. The results were as follows. 1) With the anti-hCG staining, fluorescence was observed in the syncytiotrophoblasts as reported previously while the cytotrophoblast were stained slightly. 2) with the anti-hCG-beta staining, the fluorescence was almost identical with that of hCG and showed a more distinct pattern. 3) with the anti-hCG-alpha staining, the fluorescence was found both in the syncytio- and cytotrophoblasts concurrently. Fluorescence of the latter cells was recognized as due to free alpha-subunit because cytotrophoblast was scarcely stained with anti-hCG and anti-hCG-beta.

Chorionic Gonadotropin↗
PubMed1979

The clinical evaluation of the simultaneous measurements of human chorionic gonadotropin (hCG) and its alpha-subunit in sera of patients with trophoblastic diseases.

The concentrations of human chorionic gonadotropin (hCG) and its free immunoreactive alpha-subunit (hCG-alpha) in the sera of patients with trophoblastic diseases were measured by hCG and hCG-alpha radioimmunoassay (RIA), respectively. In the sera of 12 women with hydatidiform mole large amounts of hCG and considerably high level of hCG-alpha were detected in all cases. After the evacuation of mole the serum level of these glycoproteins decreased, the leve of hCG-alpha declined more rapidly than hcg. in the sera of patients with destructive mole the concentration of hCG-alpha was usually lower than that of hCG. After hysterectomy and chemotherapy the levels of hCG-alpha declined practically paralleling that of hCG. However, when hCG had decreased to undetectable level, hCG-alpha could no longer be detected in all cases. Although in the serum of patient with choriocarcinoma involving the uterus and lungs the concentration of hCG-alpha was almost as high as that of hCG, the secretory pattern of hCG and hCG-alpha might not be closely related. The changes in the serum level of free hCG-alpha as well as that of hCG parelled the clinical course of the patients examined in this study. The present results suggest that measurements of the serum free hCG-alpha may be a useful parameter to follow the clinical course and to evaluate the efficacy of treatments of trophoblastic diseases.

Adult↗
PubMed1979

Diagnostic evaluation of progesterone. Challenge test in amenorrheic patients.

Forty-one amenorrheic patients were grouped on the basis of presence or absence of withdrawal uterine bleeding following the intramuscular administration of progesterone. Ovarian volume, ovarian morphology with particular reference to presence or absence of follicles and state of follicular development, and steroidogenic function were investigated in each group. Most of amenorrheic patients with progesterone-induced uterine bleeding had relatively large ovaries with follicles of high developmental stage (tertiary-Graafian follicle) and responded to exogenously administered HMG and HCG with a rise in the 24-hour urinary excretion of total estrogens. In contrast, most of amenorrheic patients without progesterone-induced uterine bleeding had relatively small ovaries without follicles or with follicles of low developmental stage (primordial-secondary follicle) and did not respond to exogenous HMG and HCG. The results of the present study suggest that presence or absence of progesterone-induced uterine bleeding is closely correlated with the volume, morphology and steroidogenic function of the ovary in amenornorrheic patients. Thus, pathologic amenorrhea could be divided into two groups by utilizing the progesterone challenge test and this clinical categorization might be useful for the diagnosis and treatment of amenorrheic patients.

3-Hydroxysteroid Dehydrogenases↗