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K Morishige

Publications and source records attributed to K Morishige.

51 records · Page 3Linked to original sources

Ovariectomy increases the level of estrogen receptor mRNA and estrogen receptor binding sites in female rat adipose tissue.

The roles of estrogen in the changes in estrogen receptor (ER) mRNA and ER binding sites in rat adipose tissue were studied in female rats. To elucidate the mechanism(s) behind ovariectomy (OVX)-induced obesity, the levels of ER mRNA and ER binding sites in adipose tissue were analyzed three weeks after OVX using Northern blot analysis of ER mRNA and the [3H]E2 binding assay, respectively. OVX induced an increase in body weight, and replacement of estradiol (E2) prevented that increase. Significant increases in the amounts of ER mRNA and in [3H]E2-specific binding were observed after OVX, and E2 replacement reduced both of those increases. These results suggest that E2 may regulate rat obesity directly through ER in adipose tissues.

Adipose Tissue↗

Involvement of epidermal growth factor in inducing obesity in ovariectomized mice.

Ovariectomy (Ovx) of mice significantly increases the epidermal growth factor (EGF) concentration in the submandibular gland. To elucidate the role of this elevated EGF in obesity of Ovx mice, we examined the effects of sialoadenectomy (Sx) and anti-EGF rabbit antiserum administration on the body weight (BW) gain and carcass fat deposition in Ovx animals. Studies were performed in four groups of mice consisting of control, Ovx, Ovx+Sx, and Ovx+anti-EGF groups. Ovx increased the BW gain compared with the control animals, whereas Sx and anti-EGF significantly reduced it. Although the relative weights (weight ratio to BW) of the liver and kidney were not significantly changed by Ovx, Sx, or anti-EGF treatment of Ovx mice, the relative weights of mesenteric, parametrial, and subcutaneous fat tissues were increased in Ovx mice, and this increase was significantly reduced by Sx or anti-EGF administration. Ovx induced adipocyte hypertrophy, and this effect was eliminated by Sx and anti-EGF. Moreover, acyl-CoA synthetase mRNA level was increased by Ovx, and this increase was reduced by Sx and anti-EGF in mesenteric fat tissue. These findings suggest that elevation of EGF may play a role in the induction of obesity in Ovx mice.

Acetate-CoA Ligase↗

Intraventricular administration of histidyl-proline-diketopiperazine [Cyclo(His-Pro)] suppresses prolactin secretion and synthesis: a possible role of Cyclo(His-Pro) as dopamine uptake blocker in rat hypothalamus.

Histidyl-proline-diketopiperazine [Cyclo (His-Pro) (CHP)] was discovered to be one of the metabolites of TRH. To understand the specific role of CHP in rat hypothalamic dopamine neurons, we examined the in vivo effects of intraventricular (icv) infusion of CHP on the release and synthesis of PRL in the rat pituitary and the 3,4-dihydroxyphenylacetic acid (DOPAC)/dopamine ratio in the rat hypothalamus. We also examined the in vitro effects of CHP on the release of [3H]dopamine from dispersed tuberoinfundibular dopamine neurons, [3H]dopamine reuptake in hypothalamic membrane fractions, and PRL release from rat pituitary cultured cells. Female rats were treated by icv infusion of 1 microM CHP daily for 1, 3, and 7 days, using Alzet osmotic pumps. After 1 day of treatment, the serum PRL concentration was significantly decreased. Northern blot analysis of the total RNA isolated from the pituitary glands of control animals using 32P-labeled PRL cDNA as a probe indicated the presence of PRL gene transcript, 1.0 kilobase in size, and its amount was decreased by CHP treatment. CHP did not affect [3H]dopamine release from dispersed tuberoinfundibular dopaminergic neurons at any concentration up to 1 microM. CHP did not inhibit PRL release from cultured pituitary cells at low concentrations (1-100 nM), but it stimulated PRL release at high concentrations (1 and 10 microM). We also examined the concentrations of dopamine and DOPAC in the rat hypothalamus when CHP was administered icv for 1 or 7 days. There was a significant decrease in the DOPAC/dopamine ratio after CHP treatment for 1 day. Furthermore, CHP caused dose-dependent inhibition of [3H]dopamine uptake by the rat hypothalamus similar to other dopamine uptake blockers, such as benztropine and GBR12909. These data suggest that icv administration of CHP might decrease both PRL secretion and accumulation of PRL gene transcripts in the pituitary by decreasing the DOPAC/dopamine ratio and inhibiting dopamine reuptake in the rat hypothalamus.

3,4-Dihydroxyphenylacetic Acid↗

Menstrual stage-specific expression of epidermal growth factor and transforming growth factor-alpha in human oviduct epithelium and their role in early embryogenesis.

We studied the expression of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha in human oviduct epithelium at various menstrual stages. Immunohistochemical stainings using anti-EGF and anti-TGF alpha antibodies showed a specific staining in ampullary oviduct epithelium at late follicular and luteal stages, but the stainings were very weak at early follicular stage. Quantitative reverse transcription and polymerase chain reaction, using beta-actin messenger RNA as an internal standard, revealed the menstrual stage-specific expression of EGF and TGF alpha gene transcripts: relative amounts of EGF and TGF alpha messenger RNA to those of beta-actin were 1.5 +/- 1.9% (mean +/- SD) and 1.4 +/- 0.6% (n = 3) at early follicular, 16.5 +/- 4.9% and 12.6 +/- 2.6% (n = 3) at late follicular, and 18.9 +/- 2.2% and 13.8 +/- 3.2% (n = 3) at luteal stages, respectively. The expression of these growth factors was in proportion to the increase in serum estradiol but not to progesterone levels. To clarify the biological significance of these growth factors, mouse two-cell embryos were cocultured with human oviduct epithelial cells with or without blocking the action of these growth factors. Cocultures significantly promoted blastocyst formation, but this promotive effect of the oviduct epithelial cells was completely abolished by the addition of anti-EGF and/or anti-TGF alpha monoclonal neutralizing antibodies to the coculture system. All these results showed that EGF and TGF alpha were synthesized and expressed in human oviduct epithelium specifically to menstrual stages, and that these growth factors may be involved in early embryonic development.

Actins↗

Intraventricular administration of thyrotrophin-releasing hormone (TRH) suppresses prolactin secretion and synthesis: a possible involvement of dopamine release by TRH from rat hypothalamus.

The administration of thyrotrophin-releasing hormone (TRH) causes a variety of dopamine-related biological events. To understand the specific role of TRH on rat hypothalamic dopamine neurones, we examined the in-vivo effects of intraventricular (i.c.v.) infusion of TRH on the release and synthesis of prolactin in the rat pituitary gland and on the changes in binding of [3H]MeTRH and dopamine turnover rates in rat hypothalamus. We have also examined the in-vitro effects of TRH on the release of [3H]dopamine from dispersed tuberoinfundibular dopamine neurones. Female rats were treated with i.c.v. infusions of 1 mumol TRH/1 daily for 1, 3 and 7 days using Alzet osmotic pumps. Following 7 days of treatment the serum prolactin concentrations were significantly decreased. A reduction in hypothalamic TRH-binding sites (Bmax) was also apparent but the dissociation constant (Kd) was unaffected. Northern blot analysis of total RNA isolated from the pituitary glands of control animals using 32P-labelled prolactin cDNA as a probe indicated the presence of three species of prolactin gene transcripts of approximately 3.7, 2.0 and 1.0 kb in size, and these were decreased by TRH treatment. We examined the turnover rate of dopamine in the rat hypothalamus when TRH was administered i.c.v. for 7 days. There was a significant increase in 3,4-dihydroxyphenylacetic acid/dopamine ratio with TRH treatment. Moreover, exposure to TRH stimulated [3H]dopamine release from rat tuberoinfundibular neurones in a time- and dose-dependent manner. Dopamine receptor antagonists such as SCH23390 and (-)sulpiride, and other neuropeptides such as vasoactive intestinal peptide and oxytocin did not affect TRH-stimulated [3H]dopamine release.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dihydroxyphenylacetic Acid↗

Involvement of transforming growth factor alpha/epidermal growth factor receptor autocrine growth mechanism in an ovarian cancer cell line in vitro.

Although transforming growth factor (TGF) alpha and epidermal growth factor (EGF) receptor (EGFR) autocrine mechanism is widely demonstrated in many kinds of cancers, its biological significances still remain circumstantial. We critically assessed the significance of this mechanism on the growth of an ovarian cancer cell line. Northern blot analysis in polyadenylated RNA isolated from cells by using 32P-labeled pre-TGF alpha, EGRF, and prepro-EGF complementary DNAs as probes revealed that pre-TGF alpha and EGFR but not prepro-EGF gene transcripts were expressed in the cell. TGF alpha and EGFR but not EGF proteins were observed by immunocytochemical stainings, using monoclonal antibodies against human TGF alpha, EGFR, and EGF, respectively. This cell line possessed a class of high affinity EGF receptor by 125I-EGF binding studies; Kd being 2.9 x 10(-10) M and Bmax to be 7.7 x 10(4) sites/cell. As much as 1.12 +/- 0.14 ng (SD; n = 3)/10(7) cells/24 h of TGF alpha was secreted in the conditioned media. These results suggested the expression of a TGF alpha/EGFR autocrine mechanism in this cell line. We, therefore, assessed the biological significance of this mechanism on the growth of this cell line in serum-free monolayer cell cultures. Although 0.1, 1.0, and 10 nM concentrations of TGF alpha did not show significant growth promotion, monoclonal antibodies against TGF alpha and EGFR but not EGF significantly inhibited cell growth. All these data suggested the biological importance of a TGF alpha/EGFR autocrine mechanism on the growth of this cell line in vitro.

Antibodies, Monoclonal↗

Importance of transforming growth factor alpha/epidermal growth factor receptor autocrine growth mechanism in an ovarian cancer cell line in vivo.

We have elucidated the importance of a transforming growth factor (TGF) alpha and epidermal growth factor receptor autocrine mechanism on the growth of a human ovarian serous cystadenocarcinoma-derived cell line (SHIN-3) in vitro. In this study, we studied the biological significance of this autocrine mechanism in vivo using female athymic nude (nu/nu) mice. We measured the mouse plasma epidermal growth factor and TGF alpha levels by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Plasma epidermal growth factor concentrations were remarkably decreased by sialoadenectomy (Sx): 410 +/- 65 (SE) pg/ml (n = 10) in intact animals; and undetectable in Sx mice (n = 5). Plasma TGF alpha levels were 90 and 40 pg/ml in intact and in Sx animals, respectively. Ten million SHIN-3 cells inoculated into nu/nu mice formed tumors in 100% of mice, and tumors grew progressively. Implantabilities and tumor growth rates of inoculated cells were not affected by Sx and even by Sx and anti-mouse epidermal growth factor antibody treatment. However, anti-TGF alpha monoclonal antibody (mAb) administered to SHIN-3 cell-inoculated Sx animals drastically reduced the tumor growth. Although 10(7) SHIN-3 cells formed tumors in this group, tumor growth was significantly inhibited by 10 micrograms of anti-TGF alpha mAb given 3 times a week, and growth inhibitions were more by 20 micrograms of anti-TGF alpha mAb. Moreover, as aggressive tumor growth as that in Sx animals was resumed by the cessation of anti-TGF alpha mAb treatments. All these data suggested the biological importance of a TGF alpha/epidermal growth factor receptor autocrine mechanism on the growth of this cell line in vivo.

Animals↗

Evidence for the involvement of transforming growth factor alpha and epidermal growth factor receptor autocrine growth mechanism in primary human ovarian cancers in vitro.

We examined 35 primary human ovarian adenocarcinomas for the presence of epidermal growth factor (EGF) receptor (EGFR) in plasma membranes from cancer tissues by using 125I-EGF as a ligand. Specific 125I-EGF bindings were observed in 20 (57%) of these 35 cases. Scatchard analysis showed a class of high affinity EGF receptor: Kd 5.0 +/- 1.0 x 10(-10) M; Bmax, 83.3 +/- 12.1 fmol/mg protein (mean +/- SE, n = 20). Northern analysis in polyadenylated RNA from 15 EGFR(+) cancers using pretransforming growth factor alpha (pre-TGF alpha), prepro-EGF complementary DNA, and pE7, a complementary DNA clone of human EGFR, as probes revealed that pre-TGF alpha and EGFR mRNAs but not prepro-EGF mRNA were expressed in all cases examined. Immunocytochemical studies using monoclonal antibodies (mAbs) against TGF alpha, EGF, and EGFR showed that TGF alpha and EGFR but not EGF proteins were present on ovarian cancer cells in all cases. These data suggested a possible TGF alpha/EGFR autocrine mechanism in EGFR(+) ovarian cancers. We, therefore, examined the biological significance of this autocrine mechanism by using primary monolayer cell cultures. In primary cultures from EGFR (+) cancers, TGF alpha added to the culture medium stimulated the [3H]thymidine incorporation dose dependently. Moreover, the addition of mAbs against TGF alpha and EGFR but not EGF inhibited [3H]thymidine incorporation dose dependently in EGFR(+) cancer cells. On the other hand, in primary cultures from EGFR(-) cancers, TGF alpha and anti-TGF alpha, -EGFR, and -EGF mAbs did not show any effects on [3H]thymidine incorporation. All these results suggested the possible crucial role of a TGF alpha/EGFR autocrine growth mechanism in primary human ovarian cancers which express EGFR.

Adenocarcinoma↗

Epidermal growth factor attenuates cell proliferation by down-regulating the transforming growth factor-beta receptor in the osteoblastic cell line MC3T3-E1.

We investigated the role of transforming growth factor beta 1 (TGF-beta 1) in growth regulation of the murine osteoblastic cell line, MC3T3-E1. We detected TGF-beta activity in the conditioned medium of MC3T3-E1 cells and its activity was increased by acid treatment of the bioassay system using CC1 64 cells. Northern blot analysis revealed the expression of TGF-beta 1 precursor messenger ribonucleic acid (mRNA). MC3T3-E1 cells possessed a single class of high affinity TGF-beta 1 receptor (2.8 x 10(4) sites per cell, Kd = 196 pM). Cross-linking studies revealed three specific TGF-beta receptors with molecular masses of 65, 95 and 280 kDa. Both TGF-beta and epidermal growth factor (EGF) stimulated [3H]-thymidine incorporation into cells. EGF decreased the number of TGF-beta receptor dose-dependently, and pretreatment of cells with 10 nM EGF attenuated cell growth by TGF-beta. All these data suggested that TGF-beta might be an autocrine growth factor in murine osteoblastic MC3T3-E1 cells and that EGF might modulate the growth of cells by down-regulating the TGF-beta receptor level.

Animals↗

Decrease in epidermal growth factor receptor and its messenger ribonucleic acid levels in intrauterine growth-retarded and diabetes mellitus-complicated pregnancies.

We measured the amounts of epidermal growth factor receptor (EGFR) in plasma membranes from human placentas at term delivery in three groups: appropriate for gestational age (AGA), intrauterine growth-retarded (IUGR), and diabetes mellitus-complicated (DM) pregnancies. At the same time, EGFR mRNA levels were examined in three groups by dot and Northern blot analyses. Binding studies were performed using 125I-labeled human EGF as a ligand, and two classes (high and low) of binding sites were found in all specimens. Although dissociation constants (Kd) were not significantly different among three groups, the number of binding sites was significantly decreased in IUGR and DM placentas compared to that in the AGA group. Total cellular RNA was isolated from a part of the placentas used for binding studies using the guanidinium CsCl method, denatured, and dot blotted onto nitrocellulose filter. Poly(A)+ RNA was selected from the total RNA, electrophoresed in 1% agarose gel, and transferred onto nitrocellulose filters. Then, hybridization with 32P-labeled pE7 (a cDNA of EGFR), autoradiography, and densitometry were performed. The amounts of mRNA hybridized with pE7 were reduced in IUGR and DM placentas compared to that in the AGA group. The molecular sizes of EGFR mRNA were 10 and 5.6 kilobases in all three groups. These results suggest possible physiological actions of EGF on adequate feto-placental growth and development in human pregnancy.

Diabetes Mellitus↗

Invention of anti-Leishmania drugs on the basis of the nucleoside structures.

3'-Deoxy-3'-fluoroinosine is a potent inhibitor for the growth of the promastigote form of Leishmania tropica and Leishmania donovani. In culture, the EC50 values of 3'-deoxy-3'-fluoroinosine are 2.3 x 10(-7) and 1.0 x 10(-6) M for the promastigotes of L. tropica and L. donovani, respectively. It is less toxic towards mouse mammary tumor FM3A cells: the EC50 value is 2.0 x 10(-4) M. 3'-Deoxy-3'-fluoroinosine is metabolized by Leishmania promastigotes to give 3'-deoxy-3'-fluoroadenosine-5'-triphosphate. This metabolic conversion provides a mechanism for the parasite-selective toxicity of 3'-deoxy-3'-fluoroinosine.

Animals↗

The use of serum TA-4 in monitoring patients with malignant transformation of ovarian mature cystic teratoma.

The development of cancer in mature cystic teratomas of the ovary is rare and sometimes difficult to detect because of sampling errors. Six cases of squamous cell carcinoma arising in ovarian mature cystic teratomas were studied, five of which showed an elevated level of a squamous cell carcinoma-associated antigen, TA-4, in the sera obtained preoperatively; the preoperative determination was not performed in the sixth case. However, no elevated TA-4 level was detected in the sera of 28 patients with mature cystic teratomas of the ovary. Moreover, serial determination of the serum TA-4 level showed a good correlation between the clinical course and the serum TA-4 level. Interestingly, an abnormal TA-4 level preceded the clinical detection of recurrence by 2 months in two patients. Thus, determination of the serum TA-4 concentration may be useful for diagnosing and monitoring patients with squamous cell carcinoma arising in mature cystic teratomas of the ovary.

Adult↗

Anti-parasite activity of nucleoside analogues: the metabolism of carbocyclic inosine in promastigotes of Leishmania tropica and Leishmania donovani and its activity against amastigotes of Leishmania donovani in vitro.

Carbocyclic inosine is a potent inhibitor for the growth of the promastigote form of Leishmania tropica and Leishmania donovani. In culture, the EC50 values of carbocyclic inosine are 8.3 X 10(-8) and 1.3 X 10(-7) M for the promastigotes of L. tropica and L. donovani, respectively. On the other hand, it is less toxic towards mouse mammary tumor FM3A cells: the EC50 value is 2.7 X 10(-4)M. Carbocyclic inosine is metabolized by Leishmania promastigotes to give carbocyclic adenosine-5'-triphosphate(aristeromycin-5'-triphosphate) and carbocyclic guanosine-5'-triphosphate. This metabolic conversion provides a mechanism for the parasite-selective toxicity of carbocyclic inosine. Carbocyclic inosine was found to be active against L. donovani amastigotes in an in vivo-like cultivation in vitro.

Animals↗