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Link protein (LP), an extracellular matrix protein in cartilage, stabilizes aggregates of hyaluronic acid (HA) and proteoglycans, including aggrecan and inter-alpha-trypsin inhibitor (ITI). We have shown previously that cartilage LP is present in the maturing rat and mouse ovary. In the present study, we have employed immunohistochemistry to examine the anatomical distribution of cartilage LP in the human ovary. The expression of cartilage LP was selectively detected in the cells within the granulosa compartment of the preovulatory dominant follicle. The HA-positive granulosa-lutein cells were found to be a cartilage LP-positive subpopulation. We subsequently studied the in vitro expression of cartilage LP in cultured human granulosa-lutein cells obtained at oocyte retrieval for in vitro fertilization. Analysis of cultured cells by enzyme-linked immunoaffinity assay, Western blotting and immunofluorescence microscopy revealed that gonadotropin stimulates cartilage LP production. Time-course studies indicated that the cartilage LP production was induced as early as with gonadotropin stimulation for 2 h, and the effect was sustained up to 8 h. Western blot analysis further revealed the presence of the macroaggregates composed of HA, ITI and cartilage LP in the gonadotropin-stimulated granulosa-lutein cell extracts. Collectively, the present results raise the possibility that cartilage LP forms extracellular structures that may have a regulatory function in the developing follicle in the human ovary.
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Abstract
It has been surmised that GH exerts feedback action on the hypothalamus and thereby regulates its own secretion. Our previous studies suggested that GH acts on somatostatin neurons in the hypothalamic periventricular nucleus (PeV) and neuropeptide Y (NPY) neurons in the hypothalamic arcuate nucleus (ARC). However, there remains uncertainty whether GH acts directly or indirectly through the generation of IGFs on the hypothalamus to regulate its own secretion. To examine this, rat GH (rGH) or human IGF-I was injected directly into a defined area of the hypothalamus, and the blood GH profile was observed in conscious male rats. In the rats given 0·5 μg rGH into the ARC or PeV bilaterally, GH secretion was inhibited, and the inhibition lasted for 12 h. During the period of inhibition, the duration and amplitude of GH pulses were significantly decreased and the episodic secretion of GH appeared irregularly compared with the vehicle-injected control rats. In control rats given the vehicle or those given rGH into the lateral hypothalamus, the blood GH profile did not change and pulsatile GH secretion was produced every 3 h. When 0·1 μg IGF-I was injected into the ARC or PeV bilaterally, the blood GH secretory pattern was not affected. Together with the results of our previous studies showing that c-fos gene expression was induced by systemic administration of GH and that GH receptor mRNA was contained in somatostatin neurons in the PeV and NPY neurons in the ARC, the data of the present study indicate that GH, but not IGF-I, acts on the cells in the ARC and the PeV or in their vicinity to inhibit its own secretion, presumably by activating the somatostatin and NPY neurons.
Journal of Endocrinology (1997) 153, 283–290
Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Department of Molecular Gerontology, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan
Translational Research Center, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
Department of Internal Medicine, Social Insurance Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi 273-8556, Japan
Department of Internal Medicine, Matsudo Municipal Hospital, 4005 Kamihongo, Matsudo 271-8511, Japan
Laboratory for Developmental Genetics, Riken Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
Department of Molecular Embryology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
Department of Diabetes and Metabolic Disease, Asahi General Hospital, I-1136, Asahi 289-2511, Japan
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Several mutations of the tyrosine kinase domain of insulin receptor (IR) have been clinically reported to lead insulin resistance and insulin hypersecretion in humans. However, it has not been completely clarified how insulin resistance and pancreatic β-cell function affect each other under the expression of mutant IR. We investigated the response of pancreatic β-cells in mice carrying a mutation (P1195L) in the tyrosine kinase domain of IR β-subunit. Homozygous (Ir P1195L/P1195L) mice showed severe ketoacidosis and died within 2 days after birth, and heterozygous (Ir P1195L/wt) mice showed normal levels of plasma glucose, but high levels of plasma insulin in the fasted state and after glucose loading, and a reduced response of plasma glucose lowering effect to exogenously administered insulin compared with wild type (Ir wt/wt) mice. There were no differences in the insulin receptor substrate (IRS)-2 expression and its phosphorylation levels in the liver between Ir P1195L/wt and Ir wt/wt mice, both before and after insulin injection. This result may indicate that IRS-2 signaling is not changed in Ir P1195L/wt mice. The β-cell mass increased due to the increased numbers of β-cells in Ir P1195L/wt mice. More proliferative β-cells were observed in Ir P1195L/wt mice, but the number of apoptotic β-cells was almost the same as that in Ir wt/wt mice, even after streptozotocin treatment. These data suggest that, in Ir P1195L/wt mice, normal levels of plasma glucose were maintained due to high levels of plasma insulin resulting from increased numbers of β-cells, which in turn was due to increased β-cell proliferation rather than decreased β-cell apoptosis.
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Chorioamnionitis has been shown to be one of the most important factors in inducing preterm delivery. The present study was undertaken to examine the effects of chorioamnionitis on placental endocrine functions. Preterm placentas with histologic chorioamnionitis produced smaller amounts of human chorionic gonadotropin (hCG) and human placental lactogen (hPL) than those without chorioamnionitis (P < 0.001). To examine the mechanism involved in the suppression of placental endocrine functions induced by chorioamnionitis, we initially confirmed the expression of lipopolysaccharide (LPS) receptor, i.e. the CD14 molecule, on trophoblasts by Northern blot analysis and immunohistochemistry. We then stimulated purified trophoblasts with LPS, which is the major agent which induces inflammatory responses in the host via the LPS receptor. The trophoblasts stimulated with LPS produced reduced amounts of hCG, hPL, and progesterone in a time- and dose-dependent fashion in spite of the induced manganese-superoxide dismutase (SOD) synthesis. Stimulation of trophoblasts with hypoxanthine and xanthine oxidase resulted in suppressed hCG production, while the simultaneous addition of SOD into the culture medium reversed the suppression of hCG production. LPS in the placenta with chorioamnionitis might directly stimulate trophoblasts through the LPS receptor (CD14), thus reducing placental endocrine functions. Superoxide anions which exogenously act on trophoblasts might be generated by simultaneous stimulation of neutrophils and monocytes at the feto-maternal interface by LPS, and additively reduce placental endocrine functions.
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ABSTRACT
High concentrations of a novel pituitary protein (7B2) have been shown to be present in the PC12 rat phaeochromocytoma cell line by radioimmunoassay. 7B2-like immunoreactivity (IR-7B2) was released from PC12 cells into the incubation medium in response to stimulation by a depolarizing concentration of K+, and this K+-evoked release was inhibited by Co2+, The major IR-7B2 in PC12 cell and medium appeared to be identical to that in porcine pituitary gland as judged by both gel permeation chromatography and by reverse-phase high performance liquid chromatography (HPLC). Gel permeation chromatography of extracts of cell and medium revealed two IR-7B2 peaks, the earlier eluting at a elution coefficient (K av) of 0·30 and the later at a K av of 0·54. In medium, over 90% of the IR-7B2 eluted as the earlier peak. Fractionation of extracts of cell and medium on reverse-phase HPLC showed three main IR-7B2 peaks eluting at 43, 44·5 and 46% acetonitrile/water with 0·1% trifluoroacetic acid. The findings suggest that IR-7B2 might be released by calcium-mediated exocytosis.
J. Endocr. (1986) 108, 151–155
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An accelerated polyol pathway in diabetes contributes to the development of diabetic complications. To elucidate diabetic nephropathy involving also renal tubular damage, we measured urinary sorbitol concentration concomitantly with urinary N-acetyl-D-glucosaminidase (NAG) excretion in WBN-kob diabetic rats.Twenty-four-hour urinary sorbitol concentrations increased in the diabetic rats in parallel with whole blood sorbitol concentrations. An increase in 24-h urinary NAG excretion coincided with the elevated urinary sorbitol levels in the diabetic rats. The administration of epalrestat, an aldose reductase inhibitor, reduced the increased whole blood and urinary sorbitol concentrations and urinary NAG excretion concomitantly with renal aldose reductase inhibition in the diabetic rats.These results indicate that diabetic nephropathy involves distorted cell function of renal tubules, and that treatment with epalrestat may prevent at least the progress of the nephropathy.
