Toru Hasegawa
Okayama University
PhosphorylationBone morphogenetic protein 7Internal medicineDownregulation and upregulationObstetricsEndocrinologyEndogenyReceptorChemistryAldosteronePregnancyForskolinGlucocorticoidPolycystic ovaryBone morphogenetic proteinGlucocorticoid receptorHormoneMedicineCholesterol side-chain cleavage enzymeBiologyCell biology
12Publications
4H-index
54Citations
Publications 11
Newest
#1Chiaki Kashino (Okayama University)H-Index: 1
#2Toru Hasegawa (Okayama University)H-Index: 4
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 8 authors...
To elucidate the impact of glucocorticoids on ovarian steroidogenesis and its molecular mechanism by focusing on bone morphogenetic proteins (BMPs), we examined the effect of dexamethasone (Dex) on estradiol and progesterone synthesis by using primary culture of rat granulosa cells. It was revealed that Dex treatment dose-dependently decreased estradiol production but increased progesterone production induced by follicle-stimulating hormone (FSH) by granulosa cells. In accordance with the effect...
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#1Yasuhiro Nakano (Okayama University)H-Index: 3
#2Toru Hasegawa (Okayama University)H-Index: 4
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 9 authors...
Abstract Aldosterone (Aldo) is involved in various cardiovascular diseases such as hypertension and heart failure. Aldo levels are known to be increased in patients with polycystic ovary syndrome, and expression of the mineralocorticoid receptor (MR) has also been detected in the ovary. However, the effect of Aldo on reproductive function has yet to be elucidated. Here, we examined the effects of Aldo on follicular steroidogenesis using primary culture of rat granulosa cells by focusing on the o...
1 CitationsSource
#1Yasuhiro Nakano (Okayama University)H-Index: 3
#2Toru Hasegawa (Okayama University)H-Index: 4
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 7 authors...
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#1Satoko Nagao (Okayama University)H-Index: 3
#2Nahoko Iwata (Okayama University)H-Index: 5
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 6 authors...
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#1Satoko Nagao (Okayama University)H-Index: 3
#2Nahoko Iwata (Okayama University)H-Index: 5
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 10 authors...
: A functional link between clock gene expression and ovarian steroidogenesis was studied using human granulosa KGN cells. Similarities between changes in the mRNA and protein expression levels of Bmal1 and Clock and those of Per2 and Cry1 were found in KGN cells after treatment with forskolin. Among the interrelationships between the expression levels of clock and steroidogenic factors, Clock mRNA had a strongly positive correlation with P450arom and a negative correlation with 3βHSD. Knockdown...
3 CitationsSource
#1Chiaki Kashino (Okayama University)H-Index: 1
#2Sayoko Kotani (Okayama University)H-Index: 2
Last. Mikiya Nakatsuka (Okayama University)H-Index: 23
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Abstract In the present study, we studied the effects of metformin and its interactions with the actions of bone morphogenetic proteins (BMPs) on ovarian steroidogenesis. It was revealed that metformin treatment enhanced progesterone production by human granulosa KGN cells and rat primary granulosa cells induced by forskolin and FSH, respectively. In human granulosa cells, it was found that metformin treatment suppressed phosphorylation of Smad1/5/9 activated by BMP-15 compared with that induced...
4 CitationsSource
#1Shiho Fujita (Okayama University)H-Index: 4
#2Toru Hasegawa (Okayama University)H-Index: 4
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 10 authors...
Abstract The involvement of orexins in reproductive function has been gradually uncovered. However, the functional role of orexins in ovarian steroidogenesis remains unclear. In the present study, we investigated the effects of orexin A on ovarian steroidogenesis by using rat primary granulosa cells that express both OX1 and OX2 receptors for orexins. Treatment with orexin A enhanced progesterone, but not estradiol, biosynthesis induced by FSH, whereas it did not affect basal levels of progester...
12 CitationsSource
#1Yuki Nishiyama (Okayama University)H-Index: 6
#2Toru Hasegawa (Okayama University)H-Index: 4
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 9 authors...
Abstract The effects of incretins on ovarian steroidogenesis have not been clarified. In this study, we investigated the effects of incretins, including GIP and GLP-1, on ovarian steroidogenesis using rat primary granulosa cells. Treatment with incretins significantly suppressed progesterone synthesis in the presence of FSH, and the effect of GIP was more potent than that of GLP-1. In contrast, incretins had no significant effect on estrogen synthesis by rat granulosa cells. In accordance with t...
12 CitationsSource
#1Toru HasegawaH-Index: 4
#2Yasuhiko KamadaH-Index: 15
Last. Fumio Otsuka (Okayama University)H-Index: 35
view all 8 authors...
Abstract Excess androgen and insulin-like growth factor (IGF)-I in the ovarian follicle has been suggested to be involved in the pathophysiology of polycystic ovary syndrome (PCOS). Here we investigated the impact of androgen and IGF-I on the regulatory mechanism of ovarian steroidogenesis using rat primary granulosa cells. It was revealed that androgen treatment with dihydrotestosterone (DHT) amplified progesterone synthesis in the presence of FSH and IGF-I, whereas it had no significant effect...
20 CitationsSource