Matsuzaki Kentaro, Katakura Masanori, Hara Toshiko, Li Guanghua, Hashimoto Michio, Shido Osamu
Department of Environmental Physiology, Faculty of Medicine, Shimane University, 89-1 Enya-cho, Izumo, 693-8501, Japan.
Pflugers Arch. 2009 Aug;458(4):661-73. doi: 10.1007/s00424-009-0654-2. Epub 2009 Feb 28.
Male Wistar rats, initially maintained at an ambient temperature (T (a)) of 24 degrees C, were subjected to a constant high T (a) of 32 degrees C (HE) or were constantly kept at 24 degrees C (controls, CN). Bromodeoxyuridine (BrdU) was intraperitoneally injected daily for five consecutive days after commencing heat exposure. On the 6th, 13th, 23rd, 33rd, 43rd, and 53rd day of heat exposure, rats' brains were removed. Immunohistochemical analysis showed that the numbers of BrdU-positive cells in the hypothalamus of HE were significantly and consistently greater than those of CN. In HE, the number of BrdU-positive cells double-stained by a mature neuron marker increased abruptly after 33 days of heat exposure by about seven times. This was not the case in CN. The results suggest that heat exposure facilitates proliferation of neuronal progenitor cells in the hypothalamus and promotes differentiation to neurons, which might have certain relation to establishing long-term heat acclimation in rats.
雄性Wistar大鼠最初饲养在环境温度（Ta）为24℃的环境中，之后将其置于32℃的恒定高温环境（高温组，HE），或将其持续饲养在24℃（对照组，CN）。在开始热暴露后，连续5天每天腹腔注射溴脱氧尿苷（BrdU）。在热暴露的第6天、13天、23天、33天、43天和53天，取出大鼠的大脑。免疫组织化学分析表明，高温组下丘脑BrdU阳性细胞的数量显著且持续多于对照组。在高温组中，用成熟神经元标记物进行双重染色的BrdU阳性细胞数量在热暴露33天后突然增加了约7倍。对照组则并非如此。结果表明，热暴露促进了下丘脑神经元祖细胞的增殖并促进其向神经元分化，这可能与大鼠建立长期热适应有一定关系。
