Naoki Miyakoshi
Taisho Pharmaceutical Co.
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Publication
Featured researches published by Naoki Miyakoshi.
Journal of Pharmacology and Experimental Therapeutics | 2016
Kazumi Koga; Mitsukane Yoshinaga; Yoshikatsu Uematsu; Yuji Nagai; Naoki Miyakoshi; Yoko Shimoda; Masayuki Fujinaga; Takafumi Minamimoto; Ming-Rong Zhang; Makoto Higuchi; Norikazu Ohtake; Tetsuya Suhara; Shigeyuki Chaki
A novel pyridopyrimidin-4-one derivative, N-tert-butyl-2-[2-(3-methoxyphenyl)-6-[3-(morpholin-4-yl)propoxy]-4-oxopyrido[2,3-d]pyrimidin-3(4H)-yl]acetamide (TASP0434299), was characterized as a radioligand candidate for arginine vasopressin 1B (V1B) receptor. TASP0434299 exhibited high binding affinities for human and rat V1B receptors with IC50 values of 0.526 and 0.641 nM, respectively, and potent antagonistic activity at the human V1B receptor with an IC50 value of 0.639 nM without apparent binding affinities for other molecules at 1 μM. [3H]TASP0434299 bound to membranes expressing the human V1B receptor as well as those prepared from the rat anterior pituitary in a saturable manner. The binding of [3H]TASP0434299 to the membranes was dose-dependently displaced by several ligands for the V1B receptor. In addition, the intravenous administration of [3H]TASP0434299 to rats produced a saturable radioactive accumulation in the anterior pituitary where the V1B receptor is enriched, and it was dose-dependently blocked by the oral administration of 2-[2-(3-chloro-4-fluorophenyl)-6-[3-(morpholin-4-yl)propoxy]-4-oxopyrido[2,3-d]pyrimidin-3(4H)-yl]-N-isopropylacetamide hydrochloride, a V1B receptor antagonist, indicating that [3H]TASP0434299 can be used as an in vivo radiotracer to measure the occupancy of the V1B receptor. Finally, the intravenous administration of [11C]TASP0434299 provided positron emission tomographic images of the V1B receptor in the pituitary in an anesthetized monkey, and the signal was blocked by pretreatment with an excess of unlabeled TASP0434299. These results indicate that radiolabeled TASP0434299 is the first radioligand to be capable of quantifying the V1B receptor selectively in both in vitro and in vivo studies and will provide a clinical biomarker for determining the occupancy of the V1B receptor during drug development or for monitoring the levels of the V1B receptor in diseased conditions.
Archive | 2009
Kosuke Kanuma; Naoki Miyakoshi; Madoka Kawamura; Tsuyoshi Shibata
Archive | 2013
Takashi Hashihayata; Norikazu Otake; Naoki Miyakoshi; Kazunari Sakagami
Archive | 2011
Takeshi Kuwada; Mitsukane Yoshinaga; Tomoko Ishizaka; Daisuke Wakasugi; Shin-Ichi Shirokawa; Nobutaka Hattori; Youichi Shimazaki; Naoki Miyakoshi
Archive | 2017
Kazunari Sakagami; Naoki Miyakoshi; Norikazu Otake; Takashi Hashihayata
Archive | 2017
Daisuke Wakasugi; Mitsukane Yoshinaga; Naoki Miyakoshi; Nobutaka Hattori; Shin-Ichi Shirokawa; Takeshi Kuwada; Tomoko Ishizaka; Youichi Shimazaki
Archive | 2011
Takeshi Kuwada; Mitsukane Yoshinaga; Tomoko Ishizaka; Daisuke Wakasugi; Shin-Ichi Shirokawa; Nobutaka Hattori; Youichi Shimazaki; Naoki Miyakoshi
Archive | 2011
Kosuke Kanuma; 幸祐 鹿沼; Hideaki Amada; 天田 英明; Naoki Miyakoshi; 直樹 宮腰; Tomoko Tamita; 智子 民田; Shuhei Kashiwa; 修平 柏
Archive | 2011
Takeshi Kuwada; Mitsukane Yoshinaga; Tomoko Ishizaka; Daisuke Wakasugi; Shin-Ichi Shirokawa; Nobutaka Hattori; Youichi Shimazaki; Naoki Miyakoshi
Archive | 2011
Takeshi Kuwada; Mitsukane Yoshinaga; Tomoko Ishizaka; Daisuke Wakasugi; Shin-Ichi Shirokawa; Nobutaka Hattori; Youichi Shimazaki; Naoki Miyakoshi