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Biomedical subjects

S Ueno

Publications and source records attributed to S Ueno.

At least 343 records · Page 19Linked to original sources
PubMed1988

Human recombinant mullerian inhibiting substance inhibition of rat oocyte meiosis is reversed by epidermal growth factor in vitro.

Mullerian inhibiting substance (MIS), a glycoprotein responsible for the regression of Mullerian duct in the male mammalian embryo, was recently localized not only in the fetal and newborn testis, but also in the older ovary throughout reproductive life. Bovine MIS purified from newborn testicular tissue inhibited spontaneous oocyte meiosis in vitro in the rat. These studies show that partially purified recombinant MIS produced from a human MIS genomic construct caused inhibition of oocyte meiosis, but when purified to homogeneity, the effect was lost. Addition of low concentrations of the detergent Nonidet P-40, used to maintain stability in the purified bovine preparations, however, restored the MIS inhibitory effect to the human preparation, which could, in turn, be blocked by a polyclonal antibody raised to human recombinant MIS; Nonidet P-40 itself caused no inhibition. Since we have shown that epidermal growth factor (EGF) and MIS are antagonistic in a number of other systems, we tested the effect of EGF on the ability of MIS to inhibit oocyte meiosis. EGF added to the medium at a dose that caused no effect on oocytes (25 ng/ml) blocked the MIS inhibitory action on spontaneous rat oocyte meiosis, while EGF had no effect on a known oocyte meiosis inhibitor, 3-isobutyl-1-methylxanthine. These data indicate that human recombinant MIS can inhibit oocyte meiosis in the ovary and that its regulatory effect can be modulated by EGF, which appears to be an antagonist of MIS.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Emesis induced by cancer chemotherapeutic agents in the Suncus murinus: a new experimental model.

Acute emetic responses to seven cancer chemotherapeutic agents (adriamycin, bleomycin, cisplatin, cyclophosphamide, 5-fluorouracil, methotrexate, mitomycin C) were studied in the Suncus murinus. Intravenous injection of the drugs caused vomiting with various latency. Cisplatin-induced emesis was prevented by the pretreatment with metoclopramide or chlorpromazine but not with domperidone. These results indicate that the Suncus murinus is a useful animal for testing emetic activities of cancer chemotherapeutics and antiemetic activities of prophylactic drugs.

Animals↗
PubMed1987

Suncus murinus: a new experimental model in emesis research.

Effects of various emetic and antiemetic drugs were studied using Suncus murinus for its potential use as an experimental model in emetic research. Subcutaneous injection of nicotine bitartrate (10-15 mg/kg), veratrine sulfate (0.5-1.0 mg/kg), emetine dihydrochloride (40-80 mg/kg) and oral administration of copper sulfate (20-100 mg/kg) caused dose-dependent emesis in suncus. The ED50 of nicotine, veratrine, emetine and copper sulfate were 7.9, 0.4, 47.6 and 21.4 mg/kg, respectively. However, subcutaneously injected apomorphine hydrochloride (0.1-100 mg/kg), digitoxin (0.5-1.0 mg/kg) and orally administered emetine dihydrochloride (10-80 mg/kg) did not induce the vomiting. Chlorpromazine and promethazine decreased the emetic effect of nicotine, veratrine and copper sulfate, but scopolamine hydrobromide was not effective. These results indicate that the Suncus murinus is sensitive to various emetic and antiemetic drugs and can be used as a new experimental animal model for the emesis. Emetic behavior of suncus was discussed in comparison with other animals.

Animals↗
PubMed1987

[Effects of dopamine and synthetic atrial natriuretic polypeptide on the release of norepinephrine and epinephrine from the adrenal medulla of rats].

We evaluated the effects of dopamine (DA) and synthetic atrial natriuretic polypeptide (ANP) on the release of catecholamines (CA) from the adrenal medulla. Adrenal glands of male Wistar rats were superfused with Ringer's solution saturated with 95%, O2, 5% CO2 by the use of a continuous flow incubation system, and norepinephrine (NE) and epinephrine (E) concentrations in the perfusate were continuously measured by high pressure liquid chromatography with fluorescent reaction. And the effects of DA and ANP on the CA release were evaluated. Next the effects of metoclopramide (MC), dopamine (D2) antagonist, and glucagon were added in the Ringer's solution, and the changes of NE and E in the perfusate were determined. Basal secretion of NE and E were 0.02-0.04 ng/mg.wet weight/min and 0.05-0.1 ng/mg.wet weight/min, respectively. DA remarkably decreased both NE and E release, and the suppressive effect was dependent on DA concentration in the perfusate. MC clearly raised NE and E release as well as glucagon. The increasing effect of MC was perfectly suppressed by 10(-4) M of DA. But the effect of glucagon was not blocked by the same dose of DA. Alpha rANP (10(-5)M) slightly decreased the releases of NE and E from adrenal medulla, and the magnitude of the effect of rANP was smaller than that of DA. MC significantly increased NE and E release even when the adrenal gland was superfused with Ringer's solution containing 10(-5)M of rANP. These data suggest that the release of CA from adrenal medulla may be regulated by DA, and that the receptors specifically binding to DA may exist in adrenal medulla as well as sympathetic presynaps. We concluded that DA (but not ANP) may play an important role in controlling (suppressing) the activity of sympathoadrenomedullary system.

Adrenal Medulla↗
PubMed1987

Radiotherapy of spontaneous carotid-cavernous sinus fistulas.

Between 1984 and 1986, 7 patients with spontaneous carotid-cavernous fistulas (CCF) were treated by radiotherapy delivering 3,000 cGy (200 cGy, 5 times per week) to the sellar region. Improvements of clinical signs and symptoms were seen in all patients within 6 months of treatment. During a follow-up period of 7 to 35 months, 6 patients remained in good clinical condition and only one patient developed a recurrence. As an adverse effect, one patient developed early menopause, but no other side-effects or complications were seen. Radiotherapy should be considered in patients with spontaneous CCF, when CCF are seen in middle-high aged patients and progressive without relief of symptoms.

Adult↗
PubMed1987

Distribution of alpha-(gamma-aminobutyryl)-hypusine.

The distribution of alpha-(gamma-aminobutyryl)-hypusine was examined in several organs of the rabbit and in the brain of the rat, rabbit, dog, ox, and monkey. The peptide occurred only in the brains, but appeared to be absent from dog brain. Concentrations were higher in the cerebral hemispheres than in other portions of the brain. No significant difference between white and gray matter was observed.

Animals↗