Intracellular calcium concentration in the inositol trisphosphate receptor type 1 knockout mouse

Matsuhiko Hayashi, Toshiaki Monkawa, Tadashi Yoshida, Hiroyuki Sasamura, Mineo Matsumoto, Takafumi Inoue, Katsuhiko Mikoshiba, Takao Saruta

研究成果: Article査読

10 被引用数 (Scopus)


Recently, mice with a disrupted inositol trisphosphate (IP3) receptor type 1 allele were produced by gene targeting. To examine the role of IP3 receptor type 1 in the regulation of intracellular calcium concentration ([Ca2+](i)) of glomerular cells, [Ca2+](i) was measured with fura 2- acetoxymethyl-ester in the superfused glomeruli from homozygous and wild-type mice. [Ca2+](i) was determined in calcium-free medium before and after the addition of 10-7 M endothelin-1 (ET- 1) and 10-6 M angiotensin II (AngII). The expression of mRNA of IP3 receptor isoforms and hormone receptors in the glomeruli from these animals also was measured by quantitative reverse transcription-PCR with specific primers for IP3 receptor isoforms (types 1, 2, and 3), AngII receptor type 1, and ET receptors (types A and B). In homozygous mutants, the shorter mRNA of IP3 receptor type 1, which lacks the first exon, is transcribed. Basal [Ca2+](i) and the responses to ET-1 and AngII in homozygous mutants (ET-1, 55 ± 7 nM to 73 ± 7 nM; AngII, 66 ± 6 to 91 ± 8 nM) were significantly lower than those in the wild-type mice (ET-1, 93 ± 13 nM to 162 ± 13 nM; AngII, 87 ± 7 to 147 ± 9 nM; P < 0.05 for both hormones) without significant changes in mRNA expression of hormone receptors. The results with quantitative reverse transcription-PCR also revealed that mRNA expression of the IP3 receptor gene family was not significantly different between the two groups. The present study clearly shows that IP3 receptor type 1 plays a major role in the regulation of [Ca2+](i) in the glomeruli and that lack of an isoform of IP3 receptor in the glomeruli does not induce expression of the other isoforms of the IP3 receptor.

ジャーナルJournal of the American Society of Nephrology
出版ステータスPublished - 1999 10月

ASJC Scopus subject areas

  • 医学一般


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