Involvement of L-type calcium channels in high extracellular calcium-induced increase in cytoplasmic calcium concentration in parathyroid cells isolated from the patients with secondary hyperparathyroidism.

• Project/Area Number: 21591063
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Kidney internal medicine
• Research Institution: Jikei University School of Medicine
• Principal Investigator: YOKOYAMA Keitaro 東京慈恵会医科大学, 医学部, 准教授 (70211654)
• Co-Investigator(Kenkyū-buntansha): OHKIDO Ichiro 東京慈恵会医科大学, 医学部, 助教 (40372966)
• Project Period (FY): 2009 – 2011
• Project Status: Completed (Fiscal Year 2011)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2011: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2010: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2009: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 二次性副甲状腺機能亢進症 / Ca^<2+>チャネル / 副甲状腺ホルモン / Klotho / モデルマウス / 遺伝子多型 / 心筋L型Ca^<2+>チャネル

Research Abstract

Patch-clamp and fluorescence measurements of cytoplasmic Ca2+concentration([Ca2+] i) were performed to directly detect extracellular Ca2+entry into cultured parathyroid cells from patients with secondary hyperparathyroidism. Cells loaded with fluo-3 AM or fluo-4 AM showed a transient increase in fluorescence(Ca2+transient) following 10 s exposure to 150 mM K+solution in the presence of mM external Ca2+. The Ca2+transient was completely inactivated after 30-40 s exposure to the high K+solution, was reduced by dihydropyridine antagonists, and enhanced by FPL-64176, an L-type Ca2+-channel agonist.

Research Products

• [Journal Article] Serum solubleα-Klotho in hemodialysis patients (2012)
  • Author(s): Yokoyama K, Imura A, Ohkido I, Maruyama Y, Yamazaki Y, Hasegawa H, Urae J, Sekino H, Nabeshima Y, Hosoya T
  • Journal Title: Clin Nephrol Volume: (in press)
• [Journal Article] Serum soluble α-Klotho in hemodialysis patients (2012)
  • Author(s): Yokoyama K, Imura A, Ohkido I, Nabeshima Y, Hosoya T
  • Journal Title: Clin Nephrol Volume: (in press)
  • Peer Reviewed
• [Journal Article] Alpha-Klotho(α-Kl) expressions remained in the parathyroid glands of patients with secondary hyperparathyroidism (2010)
  • Author(s): Ohkido I, Yokoyama K, Kagami S, Hosoya T
  • Journal Title: Nephrol Dial Transplant
• [Journal Article] L-type voltage-dependent calcium channel alpha subunit 1C is a novel candidate gene associated with secondary hyperparathyroidism : an application of haplotype-based analysis for multiple linked single-nucleotide polymorphisms. (2010)
  • Author(s): Yokoyama K, Urashima M, Ohkido I, Kono T, Yoshida T, Muramatsu M, Niu T, Hosoya T
  • Journal Title: Nephron Clin Pract Volume: 115(4)
• [Journal Article] The hypothesis that bone turnover influenced FGF23 secretion (2010)
  • Author(s): Ohkido I, Yokoyama K, Kagami S, Hosoya T
  • Journal Title: Kidney Int Volume: 77(8) Pages: 743-743
• [Journal Article] Should the targeted value of the phosphate be reviewed lower to normal range from the viewpoint of vascular calcification (2010)
  • Author(s): Yokoyama K, Yoshida H, Maruyama Y, Ozaki A, Yamamoto H, Hosoya T
  • Journal Title: Kidney Int. Volume: 77(10) Pages: 928-928
• [Journal Article] Alpha-Klotho (α-K1) expressions remained in the parathyroid glands of patients with secondary hyperparathyroidism. (2010)
  • Author(s): Ohkido I, Yokoyama K, Kagami S, Hosoya T.
  • Journal Title: Nephrol Dial Transplant. Volume: 25 Pages: 1008-1009
  • Peer Reviewed
• [Journal Article] L-type voltage-dependent calcium channel alpha subunit 1C is a novel candidate gene associated with secondary hyperparat hyroidisln : an application of haplotype-based analysis for multiple linked single-nucleotide polymorphisms (2010)
  • Author(s): Keitaro Yokoyama
  • Journal Title: Nephron Clin Pract. (In press)
  • Peer Reviewed
• [Journal Article] Dihydropyridine-and voltage-sensitive calcium entry in human parathyroid cells (2009)
  • Author(s): Yokoyoma K, Matsuba D, Adachi-Akahane S, Takeyama H, Tabei I, Suzuki A, Shibasaki T, Iida R, Ohkido I, Hosoya T, Suda N
  • Journal Title: Experimental Physiology Volume: 94(7) Pages: 847-855
• [Journal Article] Dihydropyridine- and voltage-sensitive Ca^<2+> entry in human parathyroid cells. (2009)
  • Author(s): Keitaro Yokoyama
  • Journal Title: Exp Physiol. 94 Pages: 847-855
  • Peer Reviewed
• [Presentation] Decrease of serum sphingosine-1-phosphate levels in hemodialysis patients with secondary hyperparathyroidism treated with Cinacalcet (2011)
  • Author(s): Yokoyama K, Ohkido I, Iwamoto T, Ishida M, Hosoya T
  • Place of Presentation: Philadelphia
  • Year and Date: 2011-12-12
• [Presentation] Mice fed adenine-containing diet is optimal model of tubulointerstitial damage with renal dysfunction (2011)
  • Author(s): Yamamoto I, Yokoyama K, Ohkido I et. al
  • Organizer: 44th Annual Meeting of American Society of Nephrology
  • Place of Presentation: Philadelphia
  • Year and Date: 2011-12-10
• [Presentation] Vitamin D analogues with TGF-β signal inhibition property ameliorates renal fibrotic lesions in UUO mice (2009)
  • Author(s): YokoyamaK, Ohkido I, Ito I, Murayama A, Yanagisawa J, Hosoya T
  • Organizer: 42th Annual Meeting of American Society of Nephrology
  • Place of Presentation: San Diego, California
  • Year and Date: 2009-10-31