Dormicaum

All experimental procedures and protocols were approved by the Animal Care and Use Committee at the Tokyo Dental College, and they conformed to the National Institutes of Health Guide for the Care and Use of Laboratory Animals. Male (n = 21) and female (n = 19) Jcl:Wister rats (6–8 weeks of age) were purchased from CLEA Japan, Inc. (Tokyo, Japan), and 5 animals of each sex were assigned to each of the three groups (LPvHiHA, cLP or dLP), with 6 male and 4 female rats used as a quality control. The rats were anesthetized by intraperitoneal administration of a mixture of medetomidine hydrochloride (0.5 mg/kg, Domitor: Meiji Seika Kaisha, Tokyo, Japan), midazolam hydrochloride (2.0 mg/kg, Dormicaum: Astellas Pharma, Tokyo, Japan) and butorphenol (0.5 mg/kg, Vetorphale: Meiji Seika Kaisha), while ocular anesthesia was achieved with oxybuprocaine hydrochloride eye drops (0.4%, Benoxil: Santen Pharmaceutical Co., Ltd., Osaka, Japan).

Before being placed into water, the hairless rats were anesthetized with an intraperitoneal injection of a mixture of medetomidine hydrochloride (0.15 mg/kg Domitor, Zenoaq, Fukushima, Japan), midazolam hydrochloride (2.0 mg/kg; Dormicaum; Astellas Pharma, Tokyo, Japan), and butorphanol (2.5 mg/kg; Vetorphale; Meiji Seika Pharma Co., Ltd., Tokyo, Japan). Thereafter, the rats were tied onto a wooden stick with three cloth tapes (Battlewin, NICHIBAN, Tokyo, Japan, Figure 6). The rats were placed into a hot tap water-filled tank (EYELA NTT 2200, 30 cm × 45 cm × 15 cm) and the water was heated by a heater to maintain the water temperature at 42 °C for 15 min. During bathing, the respiratory status was observed. The rats underwent hydrotherapy thrice a week for 4 weeks. After 4 weeks of bathing, the PI models were constructed, and the PI wounds were observed at 1, 6, 12, 24, 36, and 72 h after pressure was released.

The construction of PI rat models followed the method proposed by Chen et al. [9 (link)]. The hairless rats were anesthetized with an intraperitoneal injection of a mixture of medetomidine hydrochloride (0.15 mg/kg; Domitor, Zenoaq, Fukushima, Japan), midazolam hydrochloride (2.0 mg/kg; Dormicaum; Astellas Pharma, Tokyo, Japan), and butorphanol (2.5 mg/kg; Vetorphale; Meiji Seika Pharma Co., Ltd., Tokyo, Japan). After that, the skin on the back of the rat was pinched up, and the skin was clamped with a 10 mm diameter circular neodymium magnet (Niroku Seisakusho Co., Ltd., Kobe, Japan) with a pressure of 440 mmHg for 3 h and 50 min. To prevent direct contact with the skin, the compression side of the skin with a magnet was attached with gauze. In addition, a commercially available oily magic pen was used to mark the head, tail, and back of the pressure injuries for positioning.