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S Sakamoto

Publications and source records attributed to S Sakamoto.

At least 811 records · Page 45Linked to original sources
PubMed1981

[Effects of adrenaline, noradrenaline and pilocarpine on the oxygen uptake in rat submandibular gland (author's transl)].

This investigation was undertaken to clarify the oxygen uptake caused by adrenaline, noradrenaline and pilocarpine in rat submandibular gland. 1. Adrenaline (55 microM), noradrenaline (55 microM) and pilocarpine (10 microM) significantly stimulated the oxygen uptake. 2. When Na+ in Ringer solution was substituted by Li+ or choline, the stimulation by adrenaline, noradrenaline and pilocarpine was blocked. However, when Na+ (50%) was contained in the Li+ -Ringer solution, the response by these agents were observed. 3. When K+ in the Ringer solution was removed, the stimulation by adrenaline and noradrenaline was observed, but that by pilocarpine was not. 4. Adrenaline-, noradrenaline- and pilocarpine-induced oxygen uptake was not observed when Ca2+-deficient tissue was incubated in Ca2+-free Ringer solution. When the normal tissue was incubated in Ca2+-free Ringer solution, the stimulation by adrenaline and noradrenaline was observed, but that by pilocarpine was diminished. 5. The oxygen uptake of Ca2+-deficient tissue due to adrenaline and noradrenaline was recovered by the addition of 3 or 5 mM Ca2+ to the Ca2+-free Ringer solution, while the response of pilocarpine was recovered by the addition of 5 mM Ca2+. 6. The stimulation by adrenaline, noradrenaline and pilocarpine was considerably blocked by the addition of 2.5 or 5 mM La3+ to the Ringer solution. 7. The stimulation by adrenaline and noradrenaline was significantly blocked by the addition of 5 mM procaine. On the other hand, the stimulation by pilocarpine was blocked by 0.5 or 5 mM procaine. These results suggest that the increase in the oxygen uptake seen with adrenaline, noradrenaline and pilocarpine is dependent on the presence of Na+ and Ca2+.

Animals↗
PubMed1980

Prostaglandin F2 alpha metabolites in plasma and urine during pseudopregnancy in the rabbit.

Two prostaglandin (PG) F2 alpha metabolites, 13,14-dihydro-15-keto PGF2 alpha (dhkPGF2 alpha) in blood and 5 alpha, 7 alpha-dihydroxy-11-keto tetranorprostane 1,16-dioic acid (PGF2 alpha UM) in urine, were measured in the pseudopregnant rabbit by radioimmunoassay. During pseudopregnancy, marked increases in the two PGF2 alpha metabolites were demonstrated at about the time of luteal regression. Hysterectomy and intrauterine administration of indomethacin prolonged the life span of corpora lutea in the pseudopregnant rabbit by 8 and 5 days, respectively, with no elevation of PGF2 alpha UM excretion. The findings indicate that PGF2 alpha is a uterine luteolysin in the pseudopregnant rabbit, as in other animal species.

Animals↗
PubMed1980

[The effects of estradiol on uterine estrogen receptor and thymidine kinase in immature and spayed-adult rats (author's transl)].

Uterine estrogen receptor (ER) and thymidine kinase (TK) activity were investigated in response to an injection of estradiol (E2) (1.43microgram/100g body weight) in SD-strain immature female rats aged 21 days and spayed-adult rats aged 104 days (14 days after castration). In immature rats, uterine cytosol ER decreased abruptly after the injection of E2 and increased gradually from 4 hours later. On the other hand, nuclear ER increased rapidly and shaped a peak 1 hour after the injection of E2 and decreased gradually afterward. Uterine TK activity began to increase rapidly from 18 hours and shaped a peak 24 hours after the injection of E2 and was reduced to the same level as the controls 48 hours later. No differences in behavior of uterine cytosol and nuclear ER after the injection of E2 between immature and spayed-adult rats were noticed. Although uterine TK activity in immature rats was stimulated 30 times 24 hours after the injection of E2, that of spayed-adult rats increased by only twice. Uterine TK was separated into 3 fractions (A, B and C) by means of a DEAE-cellulose column chromatography. In immature rats, 95% of the great TK activity induced by E2 was involved in fraction A, which was not inhibited by dCTP. In contrast, uterine TK isozymes in spayed-adult rats were at fraction B and C, whose activities were inhibited by dCTP, without relation to the administration of E2. The molecular weight of fraction A was estimated to be approximately 125,000 and that of B was 100,000 by the method of gel filtration on a Sepharose CL-6B column. No differences in uterine ER levels between immature and spayed-adult rats were found, but E2-induced different TK isozymes seem to depend on the stage of uterine growth.

Animals↗
PubMed1980

Differences in the induction of thymidine kinase isozymes in estrogen-treated immature and adult rats.

Thymidine kinase activity in immature and castrated adult rat uterus has been examined in response to estrogen treatment. Following estrogen administration, it was found that immature uterine thymidine kinase activity was increased 30-fold after 24 h, but almost no effect was produced on castrated or non-castrated adult uterus. Uterine thymidine kinase activity was separated into three peaks (peak 1, 2 and 3) by means of DEAE-cellulose column chromatography. In response to estrogen, the thymidine kinase isozymes differed in adult and immature uteri. In immature uteri, marked and selective increase of the activity was found in peak I, whereas in adult only a slight increase in peak 2 activity was observed. The thymidine kinase activity in peak 1 and peak 2 were found to have different enzymatic properties and molecular weight, as determined by gel filtration of 125 000 for peak 1 and 100 000 for peak 2. From these results, it is suggested that estrogen induces specific thymidine kinase isozyme in immature uterus and that the isozyme may be involved in DNA synthesis. Such a induction mechanism seems to be lost during the development.

Animals↗
PubMed1980

Studies on the purification and characterization of human urinary plasminogen and plasmin.

A new method is described for the preparation of highly purified human plasminogen and plasmin with specific activity of 32 CTA units per mg of protein. With this method, the purification of the urinary plasminogen + plasmin antigenic materials from patients with chronic glomerulonephritis, disseminated intravascular coagulation syndrome and severe toxemia of pregnancy was performed, and the resulting highly purified proenzyme and enzyme were analyzed by immunoelectrophoresis, separative agar electrophoresis, gel filtration and SDS-gel electrophoresis. Our findings indicated that urinary plasmin reflects more closely the extent of intraglomerular fibrinolysis, while urinary plasminogen reflects non-selective proteinuria in patients with chronic glomerulonephritis or severe toxemia of pregnancy.

Animals↗
PubMed1980

Efficient induction of collagen arthritis by the use of a synthetic muramyl dipeptide.

We developed an efficient method for production of experimental polyarthritis. Native collagen (type II) from human costal cartilage was emulsified with incomplete Freund's adjuvant (IFA) containing the synthetic adjuvant N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP), and injected into one hind footpad of the PVG/c rat. This method reproducibly induced severe arthritis with high incidence, whereas the collagen alone in IFA produced mild arthritis with low incidence. MDP alone in IFA was shown to be minimally arthritogenic under identical conditions.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1980

Characterization of gangliosides in human leucocytes.

Lipids extracted from leucocyte pellets with chloroform-methanol were applied to a DEAE-Sephadex column an the gangliosides were eluted with 0.2M sodium acetate in methanol. The eluate was desalted by Sephadex G-50 column chromatography. The purified ganglioside was spotted on the high-performance than-layer plate. The plate was developed and sprayed with resorcinol reagents and heated. Seventeen bands of gangliosides were demonstrated in normal human leucocytes. The composition of these gangliosides was different in the various kinds of leucocytes. Amounts of GM3 ganglioside were apparently greater in normal lymphocytes and leukaemic cells than in granulocytes. Among the acute-leukaemic cells, some kinds of complex gangliosides were much more abundant in myelogenous cells than in lymphocytic cells. These changes in ganglioside composition are suggested as new biochemical markers for leukaemic cells.

Chromatography, Thin Layer↗
PubMed1980

Simple pelvic arteriography using a disposable elastic vein needle.

A new method for pelvic arteriography using a disposable elastic vein needle is presented. The technique is carried out by percutaneous transfemoral artery puncture and contrast medium is injected by a power air-driven injector which makes bilateral pelvic arteriography possible. Neither a radioopaque long catheter nor a guide wire are necessary in the present method. No major complications have been observed in a series of 162 cases. The present method is advantageous due to its simplicity and safety compared with ordinary Seldinger's method which is not always free of complications.

Angiography↗
PubMed1980

Evidence that proteases are involved in superoxide production by human polymorphonuclear leukocytes and monocytes.

The possible participation of proteases in superoxide (O2-) production by human polymorphonuclear leukocytes (PMN) and monocytes was explores using various protease inhibitors and substrates. Protease inhibitors of serine proteases and synthetic inhibitors that modify the active site of serine proteases. Substrates used were synthetic substrates of the chymotrypsin type as well as trypsin type of protease. All these inhibitors and substrates inhibited O2- oroduction by human PMN and monocytes induced by cytochalasin E and concanavalin A, though PMN were more sensitive to these inhibitors and substrates than monocytes. Inhibition appeared rapidly even when the inhibitors were added at the same time as the stimulants, during the "induction time of O2-production" or at the time of maximum O2- production, whereas much greater inhibition was observed when the cells were preincubated with the inhibitors. These observations suggest that enzymatically active serine proteases are essential for these phagocytic cells to initiate and maintain the O2- production in response to the stimuli. The inhibitory effect of the inhibitor and substrate for chymotrypsin type protease was greater than that of those substances for trypsin-type protease. Macromolecular inhibitors also inhibited the O2- production. These findings suggest that the serine proteases involved in the O2- production by human PMN and monocytes are similar to chymotrypsin rather than trypsin, and are possibly located at the cell surface membrane.

Adult↗