Dietary Zinc Deficiency Induces Ca_v3.2-Dependent Nociceptive Hypersensitivity in Mice

Ca_v3.2 channels belong to the T-type calcium channel (T-channel) family, i.e., low voltage-activated calcium channels, and are abundantly expressed in the nociceptors, playing a principal role in the development of pathological pain. The channel activity of Ca_v3.2 is suppressed by zinc under physiological conditions. We thus tested whether dietary zinc deficiency would cause Ca_v3.2-dependent nociceptive hypersensitivity in mice. In the mice fed with zinc deficient diet for 2 weeks, plasma zinc levels declined by more than half, and mechanical allodynia developed. The dietary zinc deficiency-induced allodynia was restored by T-channel inhibitors or by Ca_v3.2 gene silencing. These data demonstrate that zinc deficiency induces Ca_v3.2-dependent nociceptive hypersensitivity in mice, thereby suggesting that pain experienced by patients with diseases accompanied by zinc deficiency (e.g., chronic kidney disease) might involve the increased Ca_v3.2 activity.