Ddy mice

Eight-week-old male ddY mice were obtained from Japan SLC, Inc. (Tokyo, Japan), housed together in the same room and given unlimited food and water. The housing environment maintained a temperature of 23 ± 1 °C, humidity of 55 ± 5% and a regular light/dark cycle (light: 9:00–21:00, dark; 21:00–9:00). All experimental procedures using animals were approved by the Committee on Animal Experiments at Tohoku University (2020PhA-7; 17 December 2019). All experiments were carried out under the guidance of the National Institutes of Health Guide for the Care and Use of Laboratory Animals (NIH Publications No. 8023, revised 1978). All reasonable efforts were made to minimize animal stress and the number of animals used. One week later, surgery was performed on the mice, as previously described [34 (link),57 (link)]. Fourteen days after surgery, the animals were treated with the reagents described in the following section.

Animal experiments were conducted in strict accordance with the Guidelines for the Care and Use of Laboratory Animals of Kanazawa University. The animal experimental protocols were approved by the Committee on Animal Experimentation of Kanazawa University. The animals were housed with free access to food and water at 23ºC with a 12-h alternating light/dark schedule unless otherwise specified.
6-week-old male ddY mice (Japan SLC Inc., Hamamatsu, Japan) were used for all animal experiments. In the Zn-InsP6 administration group, Zn-InsP6 suspension (30 mg/0.5 mL) in 5% glucose aqueous solution was orally administrated into mice. In the InsP6 administration group, InsP6 solution (20 mg/0.5 mL) in 5% glucose was orally administrated into mice. In the control group, 0.5 mL of 5% glucose was orally administrated into mice. Then, just after the administration of Zn-InsP6, InsP6, or 5% glucose, a saline solution of [²²³Ra]RaCl₂ (9.25 kBq/100 µL) was orally administrated. Mice were sacrificed at 48 h post-administration of [²²³Ra]RaCl₂. The tissues of interest were removed and weighed, and radioactivity counts were determined. Fasting was carried out from 12 h pre-administration to 24 h post-administration to exclude the effects of diet.

The comet assay was performed using male ddY mice obtained from Japan SLC (Shizuoka, Japan). The bone marrow micronucleus assay was also conducted in these animals. The gene mutation assay was performed with male Muta™ mice, supplied by Covance Research Products (PA, USA). The peripheral blood micronucleus assay was also conducted in these animals. All animals were housed in a room maintained at 20–24 °C and 55–65% humidity with a 12 h light-dark cycle, fed commercial pellets (Oriental Yeast Industries Co., Tokyo, Japan) and given tap water ad libitum. Animal experiments were performed in accordance with the recommendations of the ethics committee of the institution. Dose (100, 200 mg/kg) were set based on the reported mouse LD₅₀ of DMAs (250-1070 mg/kg) [19 (link)].

Four-week-old male ddY mice were purchased from Japan SLC Co. Ltd. (Shizuoka, Japan) and kept in conventional conditions in a temperature- and humidity-controlled room with a 12–12 h light–dark cycle (light period, 08:00–20:00; temperature, 23 ± 1 °C; relative humidity, 55 ± 5%). Mice were fed a normal diet (CE-2; Clea Co. Ltd., Tokyo, Japan) and water ad libitum. All experimental protocols were approved by the University of Shizuoka Laboratory Animal Care Advisory Committee (approval no. 195241) and were in accordance with the guidelines of the US National Institutes of Health for the care and use of laboratory animals.

Four-week-old ddY mice (male) were obtained from Japan SLC, Inc. (Shizuoka, Japan) for the pharmacokinetic investigation of the intranasal administration. Mice weighing 25–35 g were used for the experiments after being pre-fed as previously reported [28 (link)].

Four- to 5-week old male ddy mice were purchased from Japan SLC Inc. (Shizuoka, Japan). Mice were anaesthetized deeply using isoflurane. They were sacrificed by dislocating the cervical spine. The Animal Care and Use Committee of Tohoku University Graduate School of Medicine approved our protocol for the use of animals. As we previously described, [13 (link), 15 (link), 16 (link), 22 (link), 23 (link)], we separated thymocytes from mouse thymus and resuspended them in external solution containing 145 mM NaCl, 4.0 mM KCl, 1.0 mM CaCl₂, 2.0 mM MgCl₂, 5.0 mM Hepes, and 0.01% bovine serum albumin, adjusted with pH 7.2 by titrating NaOH. We kept the isolated cells at room temperature (22-24°C) to use in 4 hours.