Effect of dimethyl sulfoxide on cooling rates of unrestrained rats

A total of 170 adult rats were exposed to 1°C, 15°C, and 25°C environments following ip injections of 3 to 6 g per kg of DMSO in saline. Shaved subjects receiving 3 g per kg of DMSO in a 1°C environment cooled to a body temperature of 10°C within 239 min; subjects receiving 6 g per kg of DMSO cooled to 10°C in 175 min. Shaved saline controls required 412 min to reach the same temperatures. Unshaved rats in a 1°C environment which were treated with 6 g per kg of DMSO cooled to 10°C within 383 min. Unshaved saline controls failed to become hypothermic. Shaved subjects injected with 6 g per kg of DMSO in an environment of 15°C gave a mixed response, a few maintaining normothermia, some cooling a few degrees and then rewarming, and 50% cooling to environmental temperatures. All controls remained normothermic. At an environmental temperature of 25°C, DMSO-treated animals dropped 3.6°C and then rewarmed. Control subjects remained normothermic. Each DMSO-treated group, therefore, manifested a significant disturbance of temperature regulation

An apparatus for the pulsating perfusion of whole organs

An organ perfusion system is presented which is simple in design, economical in construction, and easily adaptable to various laboratory requirements. The principle of operation is based on two perfusate-containing flexible plastic bags immersed in liquid upon which air impinges at controllable pressures and rates. Media from one of the bags is transmitted to the organ. The other bag receives media from the organ chamber by gravity and returns it during a pulse of over-riding pressures to the pressurized portion of the circulatory system. One-way valves prevent backflow. The system has been used to established working principles which have been proved in part by the independent maintenance of a rhythmic although somewhat diminished auricular-ventricular contractions of whole monkey hearts for a period just under 10 hrs at normo- and hypothermic temperatures. Adequate morphological preservation was observed when the hearts were sacrificed for histological study