Publications (2)12.16 Total impact
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Article: Mice lacking Ca(v)2.3 (alpha1E) calcium channel exhibit hyperglycemia.
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ABSTRACT: To investigate the functional role of Ca(v)2.3 channel in glucose homeostasis, we performed in vivo glucose tolerance and insulin tolerance tests together with stress-induced glucose release tests using mice deficient in Ca(v)2.3 channel (Ca(v)2.3-/-). The Ca(v)2.3-/- mice were significantly heavier than wild-type mice. In glucose tolerance and insulin tolerance tests, Ca(v)2.3-/- mice showed a significantly higher blood glucose level compared to wild-type mice. However, stress-induced blood glucose changes in Ca(v)2.3-/- mice were similar to those in wild-type mice. These results suggest that Ca(v)2.3 channel plays a role in glucose homeostasis by reducing insulin sensitivity and that Ca(v)2.3-/- mice exhibit symptoms resembling non-insulin-dependent diabetes mellitus.Biochemical and Biophysical Research Communications 01/2002; 289(4):791-5. · 2.48 Impact Factor -
Article: Altered pain responses in mice lacking alpha 1E subunit of the voltage-dependent Ca2+ channel.
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ABSTRACT: alpha(1) subunit of the voltage-dependent Ca(2+) channel is essential for channel function and determines the functional specificity of various channel types. alpha(1E) subunit was originally identified as a neuron-specific one, but the physiological function of the Ca(2+) channel containing this subunit (alpha(1E) Ca(2+) channel) was not clear compared with other types of Ca(2+) channels because of the limited availability of specific blockers. To clarify the physiological roles of the alpha(1E) Ca(2+) channel, we have generated alpha(1E) mutant (alpha(1E)-/-) mice by gene targeting. The lacZ gene was inserted in-frame and used as a marker for alpha(1E) subunit expression. alpha(1E)-/- mice showed reduced spontaneous locomotor activities and signs of timidness, but other general behaviors were apparently normal. As involvement of alpha(1E) in pain transmission was suggested by localization analyses with 5-bromo-4-chloro-3-indolyl beta-d-galactopyranoside staining, we conducted several pain-related behavioral tests using the mutant mice. Although alpha(1E)+/- and alpha(1E)-/- mice exhibited normal pain behaviors against acute mechanical, thermal, and chemical stimuli, they both showed reduced responses to somatic inflammatory pain. alpha(1E)+/- mice showed reduced response to visceral inflammatory pain, whereas alpha(1E)-/- mice showed apparently normal response compared with that of wild-type mice. Furthermore, alpha(1E)-/- mice that had been presensitized with a visceral noxious conditioning stimulus showed increased responses to a somatic inflammatory pain, in marked contrast with the wild-type mice in which long-lasting effects of descending antinociceptive pathway were predominant. These results suggest that the alpha(1E) Ca(2 +) channel controls pain behaviors by both spinal and supraspinal mechanisms.Proceedings of the National Academy of Sciences 06/2000; 97(11):6132-7. · 9.68 Impact Factor
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Institutions
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2002
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Tokyo Medical and Dental University
- Department of Pharmacology and Neurobiology
Tokyo, Tokyo-to, Japan
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