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Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 1,153 records · Page 64Linked to original sources
PubMed1982

[Studies on steroidogenesis in the oocyte].

The steroid hormone has an important role in the early stages of reproduction. There has been abundant histochemical evidence that oocytes contain steroid hormones and are able to synthesize these hormones. But there have been few methods of analyzing one oocyte biochemically because it is too small and light. In order to study steroidogenesis in the oocyte, a microassay method sensitive enough to analyze the enzyme activities in one oocyte was developed using enzymatic cyling for amplifying the reaction product to 10,000-fold. An oil-well technique and a microtube method were applied in the assay for achieving the reaction in a medium as small as 1.0 to 5.0 microliters under a stereomicroscope. Immature Wistar rats were superovulated by PMS-hCG administration. Oocytes were collected by puncturing the follicle and flushing the tube. They were freeze-dried after washing to remove cumulus cells. The dry weight of one oocyte was 51.2 +/- 6.2 ng in a quartz fiber fishpole balance. The activity of 3 beta hydroxysteroid dehydrogenase (3 beta HSD) (picomol/oocyte/hr, substrate:pregnenolone) in the PMS-treated oocyte was 2.66 +/- 0.59, which corresponds to 3 times the activity of the ovarian homogenate as control, indicating the high capacity of oocytes to produce progesterone. The activity increased significantly (P less than 0.01) by hCG administration up to 4.17 +/- 0.29 after ovulation, suggesting that gonadotropin regulates steroidogenesis in the oocyte. The activities of G6PD and 6PGD were 8.41 +/- 1.09 picomol/oocyte/min and 3.85 +/- 2.02 picomol/oocyte/hr, respectively. The high activity of G6PD (more than 10 times that of the ovarian homogenate) suggests that the pentose phosphate shunt concerned with steroidogenesis is active in the oocyte. HCG decreased the activities of both G6PD and 6PGD. The present results show that steroidogenesis in the oocyte is very active under the control of gonadotropin, suggesting that steroid hormones may play an important role in oocyte maturation, ovulation and fertilization.

3-Hydroxysteroid Dehydrogenases↗
PubMed1982

[Characterization of the three calcium binding proteins in the human placenta (author's transl)].

Calcium binding protein (CaBP) has been reported to be involved in absorbing calcium in the duodenum. There is some evidence to show that active transport of calcium ions occurs from mother to fetus in the human placenta. The presence of CaBP in the human placenta was examined according to Taylor and Wasserman's method, extracting the vitamin D-dependent CaBP in the duodenum, and the character of CaBP was then studied. 38,000 X g supernatant of the villous homogenate of the human placenta was heated at 60 degrees C for 5 mins to neutralize the calcium binding activity resulting from the blood. The fractions containing CaBP were separated and partially purified on Sephadex G-100 and DEAE cellulose columns. The CaBP fractions were further purified by preparative agar electrophoresis. The Chelex-100-resin method was used for the detection of calcium binding activity in the eluates and for calculation of Kd values and of calcium binding sites. The molecular weights were determined by electrophoresis of SDS-polyacrylamide gel. Three CaBPs were found in the human placenta. The molecular weight, Kd (micro M) and the binding activity (Ca mol/CaBP mol) of the three placental CaBPs were CaBP-Peak I: 82,000, 0.64, 0.52; Peak II: 12,000, 0.67, 1.10; Peak III: 8,500, 0.75, 2.08, respectively. The tyrosine residue of CaBP has been shown to act as an important binding site in that removal of calcium ions from CaBP generates a blue-shifted phenomenon in the ultraviolet difference spectrum between 270 and 300 nm. However no difference spectrum was observed with the placental CaBPs. This result was further confirmed by amino acid analysis which showed that none of the placental CaBPs contained tyrosine, tryptophan, half-cystine and proline, which are usually found in most proteins. The circular dichronism (CD) spectrum of CaBP-Peak I in the far ultraviolet range showed two negative bands at 222 and 207 nm (alpha-helix structure), and removal of calcium ions caused no difference spectrum. CD spectra of CaBP Peak II and III in the far ultraviolet range revealed random coil structures in the presence and absence of bound calcium ions. These findings indicate that the calcium binding mechanism of the placental CaBPs should be different from that of the others. In this study, three kinds of human placental CaBP newly isolated were characterized according to molecular weights, Kd values and binding activities and clarified as having an amino acid composition quite different from the CaBPs already reported.

Amino Acids↗
PubMed1982

Noradrenergic axon terminals in the substantia gelatinosa of the rat spinal cord: an electron-microscopic study using glyoxylic acid-potassium permanganate fixation.

The noradrenergic terminals in the substantia gelatinosa of the dorsal horn of the cervical spinal cord of the rat were investigated by means of the histofluorescence technique and electron-microscopic cytochemistry using the glyoxylic acid-KMnO4 fixation technique. In accordance with the topographical distribution of fluorescent catecholaminergic fibers, noradrenergic terminals containing small granular vesicles were frequently observed electron microscopically in the outer layer of the substantial gelatinosa. These terminals were most frequently found to appose (without showing typical synaptic features, small-caliber dendrites, spine apparatus, and rarely, large caliber dendrites. Only in a few cases, the noradrenergic terminals exhibited typical synaptic contacts with dendritic elements of small size. In addition, noradrenergic terminals apposed non-noradrenergic terminals containing small agranular vesicles. In rats bearing surgical lesions of the dorsal roots, no noradrenergic terminal were found in contact with the degenerated axon terminals in the substantia gelatinosa. These findings suggest that the noradrenergic afferents to the substantia gelatinosa may exert their influence on sensory transmission via dorsal horn cells.

Animals↗
PubMed1982

alpha-Adrenoceptors mediating the positive inotropic effect of phenylephrine in the right ventricular muscle of the monkey (Macaca fuscata).

The property of adrenoceptors mediating the positive inotropic effect (PIE) in the ventricular muscle of the Japanese monkey (Macaca fuscata) was investigated by the use of phenylephrine (PE) and adrenoceptor antagonists. The intrinsic activity (0.6) and the pD2-value (5.41) for PE were comparable to those in other mammalian species. The beta-adrenoceptor antagonist, pindolol (3 x 10(-8) mol/l) shifted only the upper part of the concentration-response curve (CRC) for PE to the right; the pD2-value for PE was not significantly affected by pindolol. On the other hand, phentolamine (10(-6) mol/l) shifted the lower part of the CRC for PE more than the upper part. In the presence of both pindolol and phentolamine the curve was shifted to the right in a parallel manner. The time required for twitch relaxation was negatively correlated to the degree of PIE of PE in the presence of phentolamine but not pindolol. These results indicate that both beta- and alpha-adrenoceptors mediate the positive inotropic action in the ventricular muscle of the Japanese monkey and that in contrast to the action via beta-adrenoceptors the action via alpha-adrenoceptors is not accompanied by the "relaxant effect".

Animals↗
PubMed1982

Maltose as an energy substrate during surgery: comparison of maltose with glucose.

To evaluate the usefulness of maltose as an energy substrate to be administered during surgery, five per cent maltose in lactated Ringer's solution and five per cent glucose in lactated Ringer's solution were administered to 10 cases each, at a rate of 5 ml . kg-1 hour (0.25 g . kg-1 hour as sugar) for two hours from the start of oral surgery, and their metabolic effects were compared. The maltose group showed a smaller increase in blood sugar level than the glucose group immediately after the completion of infusion. The mean plasma concentration of maltose reached a maximum of 121.6 mg/dl, and it remained at 12.3 mg/dl at four hours, indicating that the retention time of maltose in blood was longer than that of glucose. The mean recovery of sugar from four-hour urine samples was 3.26 per cent in the maltose group and 0.06 per cent in the glucose group respectively, showing greater urinary excretion by the maltose group. Plasma insulin was elevated less after maltose than after glucose infusion. The elevation following maltose infusion was considered not to be due to the administration of maltose per se, but to glucose produced from the maltose in the body. The anti-ketogenic effect of maltose was comparable to and tended to last longer than that of glucose. From overall assessment it was concluded that maltose exerts essentially the same metabolic effects as glucose when used under these conditions.

Adolescent↗
PubMed1982

Abortifacient effect and uterine cervix-dilating action of 16, 16-dimethyl trans delta 2 PGE1 methyl ester (ONO 802) in the form of a vaginal suppository (a randomized, double-blind, controlled study in the second trimester of pregnancy).

A newly synthesized 16, 16-dimethyl trans delta 2 PGE1 methyl ester (ONO 802) was clinically applied in the form of a vaginal suppository for therapeutic abortion of second trimester pregnancies. Its effects were studied in a double-blind test comparing it with an inactive placebo suppository. The study was conducted at 12 Japanese university hospitals. The number of patients was 125 in total, i.e. 63 receiving ONO 802 vaginal suppository (containing 1.0 mg ONO 802) and 62 receiving inactive placebo suppository. ONO 802 was more effective than placebo with a success rate of 87% (complete (71%) and incomplete (16%) abortions). The onset of uterine contractions was observed in 154.3+/-18.1 min. and the onset of uterine bleeding in 323.6+/-41.0 min. The expulsion of the fetus and placenta was observed in 955.4+/-97.0 and 961.6+/-97.0 min., respectively. The cervix dilating effect of ONO 802 was observed in 63.5% of the patients at 3 hours after the start of administration. Nausea, vomiting, abdominal cramps, diarrhea and pyrexia were noticed. However, all these side effects were transient and mild, requiring no treatment. No abnormality was observed in the puerperal course, duration of uterine bleeding or onset of subsequent menstruation following the therapeutic abortion. Therefore, the present study demonstrated that ONO 802 vaginal suppository was an effective and valuable drug for therapeutic abortion of second trimester pregnancies.

Abortifacient Agents↗
PubMed1982

Purification of RNA associated and unassociated forms of 1,4-alpha-glucan branching enzyme from rat liver.

Two molecular forms (BE-I and -II) of 1,4-alpha-glucan branching enzyme were purified from rat liver by affinity chromatography on glycogen-adipoyldihydrazide-Sepharose 4B and glycogen-ethylenediamine-Sepharose 4B, respectively, after hydrophobic chromatography on hexylamine-Sepharose 4B, as single proteins with the same molecular weight of 82,000 on SDS-polyacrylamide gel electrophoresis. By comparing their UV spectra and by RNA detection on polyacrylamide gels after electrophoresis, BE-I and -II were identified to be RNA associated and unassociated forms, respectively. The molecular weights of BE-I and -II estimated by Sephadex G-200 gel filtration were 91,000 and 98,000, respectively, indicating that both forms consist of a monomer. As Be-II had about half the specific activity of BE-I, the RNA component was not essential for the activity of the rat liver branching enzyme, and it was also dissociable from the protein component (BE-II) on polyacrylamide gel electrophoresis at pH 7.3, whereby BE-II showed a heterogeneity of at least three microspecies as revealed by protein staining as well as by activity staining of the gels. Using the antibody against BE-I, BE-I and -II were indistinguishable on immunodiffusion, and the activity inhibition rate of BE-II by the antibody was almost the same as that of BE-I if their specific activities are considered, indicating that the RNA component may have no effect on the enzyme-antibody reaction. Immunochemically no isoenzyme was detected for this enzyme in rat tissues.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1982

Photoinhibition of Reaction Centers of Photosystems I and II in Intact Bryopsis Chloroplasts under Anaerobic Conditions.

Illumination of intact Bryopsis corticulans chloroplasts under anaerobic conditions induced a decline of chlorophyll fluorescence and photoinhibition of Photosystems I and II. The time course of the light-induced decline of chlorophyll fluorescence and the decreases of activities of reactions sensitized by Photosystems I and II were compared. Photosystem I activity decreased in parallel with the disappearance of active P700. The time course of the destruction of the reaction center of Photosystem II was similar to that of photoinhibition of 2,6-dichlorophenolindophenol-Hill reaction.It appears that the initial events in photoinhibition are the destruction of the reaction centers of Photosystems I and II and that the reaction centers that are inhibited become quenchers of chlorophyll fluorescence.Effects of inhibitors of electron transfer and of an electron donor to Photosystem I showed that photoinhibition was related to Photosystem I activity.

Journal Article↗
PubMed1982

Mechanism of photoactivation of electron transport in intact bryopsis chloroplasts.

The mechanism of photoactivation of photosystem I electron transport was studied in intact Bryopsis corticulans chloroplasts. The evidence from chemical and photochemical studies suggests that photoactivation is a consequence of a reduction of an electron transport component, presumably ferredoxin-NADP(+) reductase. O(2) does not act as a mediator of the process but rather acts as an electron acceptor after photoactivation has occurred. We suggest that the initial function of the chloroplasts in a transition from dark to light is to initiate pseudocyclic electron flow.

Journal Article↗
PubMed1982

A biochemical study on glycosaminoglycans (mucopolysaccharides) in emphysematous and in aged lungs.

Quantitation of glycosaminoglycans (GAGs) in the lungs from different age groups indicated that the amount of GAGs was lower in the group 70 yr of age and older compared with that in the groups 30 to 39 and 40 to 49 yr of age, respectively (p less than 0.05). There was no difference in the relative ratio of individual GAG species (hyaluronic acid: chondroitin sulfate (A(C): dermatan sulfate: heparan sulfate) of the lung among the groups 40 to 49, 50 to 59, 60 to 69, and 70 or more yr of age. Hence, it was suggested that senescence of the lung was associated with a uniform decrease of all the GAG species in the lung. On the contrary, emphysematous lungs were characterized by a decrease in relative percentage of hyaluronic acid in comparison with control lungs (p less than 0.01).

Adolescent↗
PubMed1982

Evidence for host-mediated antitumor activity in the treatment of experimental tumor with a hot water extract from BCG.

Studies were undertaken for the evaluation of the mechanism responsible for antitumor effects of hot water extract (HWE) of BCG on murine ascites tumor cells. a) The viability of tumor cells has remained unchanged after incubation of tumor cells in the medium containing HWE. b) There was no difference in survival time between mice which had received tumor cells treated as in (a) and the control mice. c) Silica, carragheenan and cortisone acetate reduced the antitumor effect of HWE in ddY mice and C3H/He mice which had been inoculated with Sarcoma 180 cells or MH134 cells. d) The growth of tumor cells was retarded when they were inoculated subcutaneously together with peritoneal cells from HWE-injected mice. These results indicate the participation of host-mediated antitumor activity when neoplasms were treated with HWE.

Animals↗
PubMed1982

Effects of nicorandil and its congeners on musculature and vasculature of the dog trachea in situ.

In anesthetized dogs, the tracheal vascular bed in situ was perfused with arterial blood through the cannulated cranial thyroid arteries. The effects of nicorandil, a coronary vasodilator, and its congeners (SG-212, GS-209 and SG-103; in which the nitroxy group of nicorandil was substituted for other groups) on the tracheal musculature and vasculature were examined. All drugs were injected intra-arterially. Nicorandil (10-300 micrograms), SG-212 (100 micrograms-3 mg), SG-209 (100 micrograms-3 mg) and SG-103 (100 micrograms-3 mg) all produced a decrease in tracheal tone elevated by neostigmine (tracheal dilatation) and an increase in tracheal blood flow (tracheal vasodilatation). Relative potencies of these effects were in the descending order: nicorandil greater than SG-212 = SG-209 = SG=103 in producing tracheal vasodilatation. These results suggest that nicorandil would also be a potential bronchodilator and that the nitrate site in nicorandil plays a role in potentiating the pharmacological activity of congeners of nicorandil.

Animals↗