A new harvesting method prolongs survival of cardiac xenografts from guinea pig to rat.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
K Shiota
Publications and source records attributed to K Shiota.
Glycosphingolipid composition of rat placenta: changes associated with stage of pregnancy.
The composition of glycolipids and their changes in the placenta were investigated in the normal pregnant rat. Total lipid fractions extracted from the placenta between days 12 and 20 of pregnancy (day 0 = oestrus) were subjected to glycolipid analysis using DEAE-Sephadex chromatography, silica-gel HPLC, silica-gel TLC, TLC/immunostaining, matrix-assisted secondary-ion mass spectrometry in the negative-ion mode and 1H NMR. Glycolipids identified in the rat placenta were: gangliosides GM3 (NeuAcLacCer and NeuGcLacCer) and GD3 (NeuAcNeuAcLacCer, NeuAcNeuGcLacCer and NeuGcNeuAcLacCer), and neutral glycolipids ceramide monosaccharide (CMH) (GlcCer), ceramide disaccharide (CDH) (LacCer), ceramide trisaccharide (CTH) (Gb3Cer) and ceramide tetrasaccharide (CQH) (Gb4Cer). The content of neutral glycolipids was higher than that of gangliosides throughout pregnancy. Of the neutral glycolipids, CMH and CTH predominated and the level of CDH was low at mid-pregnancy. During late pregnancy, CMH and CTH decreased and CDH increased markedly. CQH remained at a low level throughout pregnancy. Of the gangliosides, GM3 was predominant on days 12-16 and then decreased, whereas GD3, which was low on day 12, increased slightly on day 16 and maintained the same level thereafter. Immunohistochemical studies indicated that these changes in the expression of major gangliosides from GM3 to GD3 occurred in labyrinthine trophoblasts. Thus expression of these glycolipids appears to change markedly during pregnancy.
Animals↗
Programmed cell death in the interdigital tissue of the fetal mouse limb is apoptosis with DNA fragmentation.
BACKGROUND: Programmed cell death is an essential event during mammalian morphogenesis which eliminates unnecessary cells to accomplish histogenesis and organogenesis. Cell death in interdigital spaces of the developing limb is a classical example of morphogenetic cell death. We investigated whether classical programmed cell death in the interdigital tissue of the developing limb in mice is apoptosis with fragmentation of nuclear DNA and also examined sequentially the occurrence of programmed cell death and cell proliferation in the developing limb of mouse fetuses to analyze their interrelation. METHODS: We examined the occurrence of apoptotic cell death in the developing limbs of mouse fetuses by using Nile blue sulphate staining, agarose gel electrophoresis for detecting DNA laddering, and a cytochemical labeling of DNA fragmentation. We also labeled proliferating cells using BrdU/anti-BrdU immunohistochemistry and examined the interrelation between apoptotic programmed cell death and cell proliferation. RESULTS: DNA ladders, a biochemical evidence of apoptosis, were detected in DNA extracts from the interdigital tissue of day 13 mouse fetuses by agarose gel electrophoresis. Programmed cell death and DNA fragmentation were detected by Nile blue staining and cytochemical labeling of DNA fragmentation, respectively, in the interdigital mesoderm and in the regions of presumptive joints of the digit. BrdU/anti-BrdU immunohistochemistry for identifying proliferating S-phase cells revealed that interdigital mesenchymal cells cease DNA synthesis before programmed cell death and DNA fragmentation begin. CONCLUSIONS: We confirmed that both cytological apoptotic alterations and fragmentation of nuclear DNA occur in the interdigital tissue and presumptive joint areas of fetal mouse limbs, and they appear to play a significant role in the separation of digits as well as the formation of joint cavities.
Animals↗
Effects of ethanol on the pancreas of disulfiram-treated rats.
To study the effects of ethanol on disulfiram-treated rats, we administered ethanol orally at a does of 2000 mg/kg, twice daily for 5 days. The administration of ethanol or disulfiram alone produced no recognizable changes in pancreatic acinar cells. Ethanol administration, in disulfiram-treated rats resulted in a decrease in the content of zymogen granules in acinar cells, and the appearance of intraplasmic vacuolization. Electron microscopically, these vacuoles appeared on the basal side of nuclei. In addition, similar vacuoles appeared in liver cells, and these vacuolizations seemed to show lipid inclusions. However, ethanol administration to disulfiram-treated rats did not cause inflammatory changes or edema in the pancreas. A comparison of blood ethanol levels in rats receiving ethanol alone and disulfiram plus ethanol showed no significant difference, but acetaldehyde levels in rats receiving ethanol plus disulfiram rats were significantly higher than those in rats receiving ethanol alone. These findings suggested that acetaldehyde caused a decrease of zymogen granules and the presence of lipid inclusions in pancreatic acinar cells.
Acetaldehyde↗
Effects of methamphetamine on rat embryos cultured in vitro.
Wistar rat embryos were explanted on day 10.5 of gestation and exposed in vitro to methamphetamine (MAMP) at a concentration of 0.1, 0.2, 0.4, 0.6, or 0.8 mM for 24 h, and the direct teratogenic effects of the drug on rat embryos were examined. The viability of cultured embryos was not affected by the MAMP treatment. The yolk sac diameter was reduced at MAMP concentrations of 0.6 and 0.8 mM. The crown-rump length and the somite number of the embryos decreased significantly and dependently on the MAMP concentrations at 0.4-0.8 mM. The protein content was also significantly reduced at 0.4-0.8 mM. The developmental score was decreased in a concentration-dependent manner. The frequency of malformed embryos significantly increased at 0.6 and 0.8 mM. The malformations induced in treated embryos included microcephaly, neural tube defects, incomplete rotation of the body axis, and tortuous spinal cord. Abnormal histological changes such as derangement and necrosis in the neuroepithelial tissue were observed in embryos exposed to high concentration of the drug. Our results revealed the direct embryotoxic and teratogenic effects of MAMP in the rat.
Abnormalities, Drug-Induced↗
Disruption of the mouse RBP-J kappa gene results in early embryonic death.
The RBP-J kappa protein is a transcription factor that recognizes the sequence C(T)GTGGGGA. The RBP-J kappa gene is highly conserved in a wide variety of species and the Drosophila homologue has been shown to be identical to Suppressor of Hairless [Su(H)] which plays important roles in the development of the peripheral nervous system. To explore the function of the RBP-J kappa gene in mouse embryogenesis, a mutation was introduced into the functional RBP-J kappa gene in embryonic stem (ES) cells by homologous recombination. Null mutant ES cells survived but null mutant mice showed embryonic lethality before 10.5 days of gestation. The mutant mice showed severe growth retardation as early as 8.5 days of gestation. Developmental abnormalities, including incomplete turning of the body axis, microencephaly, abnormal placental development, anterior neuropore opening and defective somitogenesis, were observed in the mutant mice at 9.5 days of gestation. RBP-J kappa mutant embryos expressed a posterior mesodermal marker FGFR1. Their irregularly shaped somites expressed a somite marker gene Mox 1 but failed to express myogenin. The RBP-J kappa gene was revealed to be essential for postimplantation development of mice.
Animals↗
[A case report of heterochronic double cancer of the liver with type C liver cirrhosis].
Explore the source record for details and available documents.
Adenoma, Bile Duct↗
Cytochemical identification of programmed cell death in the fusing fetal mouse palate by specific labelling of DNA fragmentation.
The process of palate fusion was examined in 13- and 14-day-old mouse fetuses by using in situ staining for nuclear DNA fragmentation (TUNEL method) and immunofluorescent staining for keratin, with special reference to the disruption of the midline epithelial seam. TUNEL-positive cells were found in the disappearing midline seam and the oral and nasal epithelial triangles at some late stages of palate fusion, but not in the palatal shelves prior to contact or in the intact midline epithelial seam. It seems that DNA fragmentation or apoptosis is required for the midline epithelial seam to disrupt, but may not be necessary for initial contact of palatal shelves or for the epithelial fusion of opposing palatal shelves. A similar sign of apoptotic cell death was observed in the disappearing epithelial seam between the fusing nasal septum and dorsal palate. We have demonstrated that apoptotic programmed cell death does occur at some stages of palate fusion, although the present results do not exclude the possibility of epithelial-mesenchymal transformation and the oral and nasal migration of midline epithelial cells.
Animals↗
Expression of epidermal growth factor receptor after partial pancreatectomy in adult rats: an immunohistochemical study.
The expression and localization of epidermal growth factor (EGF) were investigated immunohistochemically using an anti-EGF receptor antibody in the pancreas of partial pancreatectomized and sham-operated adult rats. In the sham-operated pancreas, immunoreactive products against EGF receptor were only slightly positive in the pancreatic acinar cells. In the partial pancreatectomized pancreas on the fifth day after operation, EGF receptor immunoreactivity was intensely positive in the acinar cells, in some cells lining the intercalated ducts and some basal cells of the acinus, but it was not detected in the pancreas when exogenous EGF was given to the rat after partial pancreatectomy for three days. The present results suggest that EGF receptor is expressed in the regenerating pancreatic tissue, and EGF could be involved in the mechanism of pancreatic regeneration in rats.
Animals↗
Immunohistochemical study on epidermal growth factor (EGF) receptor during carcinogenesis in the rat liver.
The expression and localization of epidermal growth factor (EGF) receptor were investigated immunohistochemically using anti-EGF receptor antibody in the normal rat liver and 3'-methyl-4-dimethylaminoazobenzen (3'-Me-DAB) induced tumors in rats. In 8 weeks after 3'-Me-DAB treatment, multiple nodules of cholangiocarcinoma were found in the rat liver, and atypical nodules of hepatocytes were also found 14 weeks later. Immunoreactive products against EGF receptor were only slightly positive in the normal liver, the nodule of cholangiocarcinoma, and atypical nodule of hepatocytes. It was noted that EGF receptor immunoreactivity was more intense in non-cancerous tissue adjacent to tumorous nodules than in the cancerous tissue. The present finding suggests that the expression of EGF receptor may be associated with regenerating as well as carcinogenetic processes in the rat liver.
Adenoma, Bile Duct↗
Splenic macrophages enhance prolactin-induced progestin secretion from mature rat granulosa cells in vitro.
The effect of splenic macrophages on in vitro progestin secretion (the sum of the progesterone and 4-pregnen-20 alpha-ol-3-one concentrations in the medium) from mature rat granulosa cells was examined by means of co-culture techniques. When splenic macrophages (3.0 x 10(5) cells/ml) obtained from adult female rats on the evening of proestrus (1800 h) were added to granulosa cells (1.5 x 10(5) cells/ml) and co-cultured for 96 h in the absence of prolactin (PRL), progestin secretion from granulosa cells did not change. However, co-culture of granulosa cells with the macrophages in the presence of PRL (2 micrograms/ml) significantly enhanced progestin secretion after 48 h of culture. This stimulatory effect on progestin secretion was observed only when the number of macrophages added was more than twice the number of granulosa cells. On the other hand, splenic macrophages obtained on the evening of diestrus had no effect on progestin secretion from granulosa cells even in the presence of PRL. These results suggest that splenic macrophages can enhance PRL action so as to stimulate progestin secretion from granulosa cells and that this function of splenic macrophages varies during the estrous cycle.
Animals↗
The induction of neural tube defects by maternal hyperthermia: a comparison of the guinea-pig and human.
In our recent studies on the effects of maternal hyperthermia on the embryonic guinea-pig, we have demonstrated two 'teratogenic windows' at embryonic days 13 and 21 (E13 and E21). E13 encompasses the period of the closure of the neural groove and anterior neuropore, and E21 the commencement of the cortical plate. The approximate equivalent developmental times in the human are E23-E25 and E49-E56 respectively. In the guinea-pig, maternal hyperthermia at E13 results in a high incidence of neural tube defects (NTD), many open, and associated with other defects such as microphthalmia, and scoliosis or kyphosis. The NTD were most common in the developing hindbrain and all demonstrated considerable infoldings of neural tissue, rosettes of neuroepithelial cells, outpocketings of neural tissue and large cystic cavities beneath the defect. In human examples from the Kyoto Human Embryo Collection, 16 had verified hyperthermic insults at E23-E25 and all had NTD which showed similar deformities to the guinea-pig. Most embryos with such gross defects are aborted in the early fetal period in both species.
Animals↗
Biochemical analysis of the bone of SHC rats with spontaneous hypercholesterolemia and renal dysfunction.
Spontaneously hypercholesterolemic (SHC) rats exhibit severe abnormalities in renal function and bone metabolism at old ages, in addition to hypercholesterolemia. SHC rats were also found to show endocrine abnormalities such as hyperthyroidism from young ages. In this study, biochemical and microdensitometric analyses were carried out using femurs to characterize further the abnormality in bone metabolism: whether biochemical markers of the bone may be affected by these abnormalities. At 6 weeks of age, the ashed weight and calcium content of the dried femurs were slightly lower in SHC rats than in age-matched Sprague-Dawley (SD) rats. None of the markers of microdensitometric analysis was changed. At 24 weeks of age, the ashed weight of dried femurs and the density of the marrow region of femurs were lower in the SHC rats. The results indicate that SHC rats exhibit severe abnormality in bone metabolism leading to biochemical changes in the bone at old ages whereas changes in bone markers were minimal at young ages before the onset of severe renal dysfunction.
Animals↗
Paracrine effect of folliculo-stellate cells on the growth factor-like action of activin A in anterior pituitary cultures.
Several studies have shown that pituitary folliculo-stellate (FS) cells exhibit local functions within the pituitary gland. On the other hand, we have shown previously that activin A increases the number of FSH-producing gonadotropes in cultured rat anterior pituitary cells. In this study, we investigated whether FS cells exert an influence on the action of activin A. FS cells were prepared by culturing the dispersed rat anterior pituitary cells in media containing 15% fetal calf serum and 6 mM glutamine for 15 days. Most cells had the morphological characteristics of FS cells and S-100 protein immunoreactivity, a specific marker of FS cells. The number of FSH cells, which was higher in activin A-treated than in control cultures, was reduced to the control level by incubation with activin A plus conditioned media from FS cell-enriched cultures (FSCM). This inhibitory effect of FSCM was neutralized by a follistatin antibody, but not by anti-S-100 protein or anti-basic fibroblast growth factor. Furthermore, follistatin suppressed activin A stimulated increases in the number of FSH cells in a similar inhibitory pattern to that of FSCM. Meanwhile, the number of FSH cells was not affected by FSCM or follistatin in the absence of activin A. These results suggest that FS cells are involved in the regulation of the function and/or the morphogenesis of the FSH cell-lineage by affecting the action of activin A, and that this paracrine effect of FS cells is mediated by follistatin.
Activins↗
Translation of rat ovarian mRNA to two 20 alpha-hydroxysteroid dehydrogenase isozymes in Xenopus oocytes.
20 alpha-Hydroxysteroid dehydrogenase (20 alpha-HSD) in rat luteal tissue catalyzes the conversion of progesterone into a biologically inactive steroid, 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OHP) and depletes the output of progesterone into the circulation. An increase in 20 alpha-HSD activity in luteal tissue is therefore a prerequisite for the regression of functional corpora lutea in rats. We have reported that ovarian 20 alpha-HSD is composed of two isoforms (HSD1 and HSD2). In this study, among batches of ovaries collected randomly during the estrous cycle, we selected two batches (batches A and B): the cytosol preparation from batch A contained both HSD1 and HSD2 activities, whereas that from batch B contained only HSD1 activity. From these 2 batches, we extracted mRNA, and each mRNA preparation was subjected to translation in Xenopus oocytes. The translation products of batch A exhibited both HSD1 and HSD2 activities, and those of batch B only HSD1 activity in accordance with the enzymatic activities observed in the respective cytosolic preparations. The results are compatible with the presence of two distinct mRNAs coding HSD1 and HSD2, and if so their transcription will be regulated separately according to the functional state of the ovary.
20-Hydroxysteroid Dehydrogenases↗
Splenic macrophages enhance prolactin and luteinizing hormone action in rat luteal cell cultures.
We have reported that splenic macrophages play a role in the regulation of progestin secretion in rats. In this study, splenic macrophages were obtained from cycling rats at different estrous cycle stages and co-cultured with luteal cells from mid-pseudopregnant rats in the absence/presence of prolactin (PRL) or luteinizing hormone (LH). The effect of macrophages on the luteotropic action of PRL and LH was evaluated with 2 parameters, i.e. an increase in total progestin output (progesterone plus 20 alpha-hydroxyprgn-4-en-one [20 alpha-OHP]), and an increase in the progesterone to 20 alpha-OHP (P/20 alpha-OHP) secretion ratio. Splenic macrophages obtained from proestrous or metestrous rats enhanced the PRL action to increase the P/20 alpha-OHP secretion ratio, but those from estrous or diestrous donors did not. Only macrophages from proestrous donors enhanced the PRL action to increase the total progestin output. In contrast, the LH action increasing the P/20 alpha-OHP secretion ratio was enhanced by splenic macrophages regardless of the donors' estrous cycle stages. The LH action increasing the total progestin output was enhanced only by proestrous or metestrous macrophages. Therefore, if luteal cells are co-cultured with proestrous macrophages, the luteotropic actions of PRL and LH can be fully expressed. These results indicate that splenic macrophages directly act on luteal cells and enhance the luteotropic action of PRL and LH, and that this function of splenic macrophages is modified somehow according to the donors' estrous cycle stages.
Animals↗
Expression of activities of two 20 alpha-hydroxysteroid dehydrogenase isozymes in rat corpora lutea.
The rat ovary contains two isozymes of 20 alpha-hydroxysteroid dehydrogenase (HSD-1 and HSD-2). In this study, the expression of activity of each isozyme was investigated in ovaries that contained a single generation of corpora lutea during pseudopregnancy. This condition was induced by cervical stimulation in rats that had been rendered anovulatory by housing them in a continuously lit environment. The total activity of cytosolic 20 alpha-HSD was lower in the ovaries of these pseudopregnant rats than in ovaries containing multiple generations of corpora lutea. In normal pseudopregnancy, HSD-1 activity was low on days 5 and 9 and increased markedly on day 15, whereas HSD-2 was lower than HSD-1 and did not vary throughout pseudopregnancy. However, on days 5 and 9 of continuous-light pseudopregnancy, low activity of HSD-1 only was detected; by day 15, HSD-1 activity had increased sixfold and HSD-2 activity could be detected. Immunohistochemical methods using a specific antibody recognizing both HSD-1 and HSD-2 revealed that the number of 20 alpha-HSD-positive luteal cells increased by day 15. Thus, the increase in total enzyme activity and appearance of HSD-2 activity observed at late pseudopregnancy was accompanied by an increase in the number of 20 alpha-HSD-positive luteal cells.
20-Hydroxysteroid Dehydrogenases↗
Purification and characterization of rat ovarian 20 alpha-hydroxysteroid dehydrogenase.
To investigate the regulatory mechanism of 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) (EC 1.1.1.149) activity in ovarian tissue, the enzyme was purified from ovaries of normal mature female rats. Column chromatography of the cytosolic fraction from ovaries on DEAE-Toyopearl 650M revealed two peaks of the 20 alpha-HSD activity at different ionic strengths. These peaks were designated HSD1 and HSD2, respectively. Each of the active fractions was further purified to homogeneity by dye-affinity chromatography using Matrex Green A and AF Red-Toyopearl. Both the fractions appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (at Mr = 33,000 under reducing conditions). Under non-reducing conditions, similar values were obtained on gel-exclusion HPLC, indicating that the enzyme fractions were single-stranded, monomeric polypeptides. Homogeneous HSD1 and HSD2 were purified 361-fold and 509-fold, respectively, and differed in their substrate preference. The two enzyme fractions had Km values of 4.75 microM and 5.16 microM for 20 alpha-dihydroprogesterone, respectively, and showed almost the same RF values on reverse-phase HPLC and free-zone capillary electrophoresis. However, amino acid composition was slightly different, i.e. lysin content was higher in HSD1 than HSD2. Thus, it was clarified that two types of 20 alpha-HSD with very similar molecular structures are present in the rat ovary.
20-Hydroxysteroid Dehydrogenases↗