摘要
健康家兔24只,分成4组,每组6只。1组为热应激组;2～4组为热习服组,分别热习服6天、11天和16天。热习服各组每天热暴露至肛温(Tr)41.5℃。用放射免疫法测定了各组末次热暴露前和Tr 41.5℃、42.5℃时家兔血浆、脑脊液(CSF)和视前区——下丘脑前区(POAH)环腺苷酸(cAMP)含量。各组末次热暴露耐热时间较首次延长26%～45%。热前血浆cAMP含量较第1组分别增高23%、53%和76%;Tr 41.5℃时增幅由第1组的160%分别降为76%、39%和19%,Tr 42.5℃时则由254%分别降为180%、118%和88%,而其绝对含量较第1组降低不明显(p>0.05)。CSF中cAMP含量变化类似血浆,但含量值均较第1组明显升高,第3、4组Tr 42.5℃时较41.5℃时反有降低趋势(p>0.05),第4组Tr 42.5℃时较第1组仅增高10%(p>0.05)。POAH中cAMP含量变化与CSF中相反,负相关非常显著(p<0.01),第4组Tr 42.5℃时,与第1组几无差别。以上表明,第3、4组热习服后耐热时间显著延长,血浆、CSF和POAH中cAMP含量的变化反映了热应激植物性反应的减弱,以16天组(第4组)最好;CSF中cAMP与POAH中cAMP的代谢有密切关系。
Healthy adult rabbits were divided into four groups: heat stress group; 6-day heat acclimatizaed group; 11-day group; 16-day group. The acclimatization groups were exposed to heat once daily until their rectal temperature raised to 41.5°C. The cAMP contents were measured by radio-immunoassy method in plasma, cerebrospinal fluid (CSF) and preoptic area-hypothalamus (POAH) from six rabbits of each group before heat and during Tr 41.5°C and 42.5°C at the last heat exposure. The duration of heat tolerance to the last heat exposure of group 2 to 4 rabbits prolonged by 26~45% as compared with that to the first exposure. Before heat, the cAMP content in plasma of rabbits in groups 2,3 and 4 rose by 23% , 53% and 76% respectively as compared with that of rabbits in group 1. At Tr 41. 5°C, the rise of cAMP content in plasma dropped from 166% in rabbits of group 1 to 76% , 39% and 19% in rabbits of group 2, 3 and 4 respectively. At Tr 42. 5°C , they dropped from 254% to 180%, 118% and 88% respectively. However, the value of cAMP content in plasma of group 4 rabbits decreased less than that of group 1 (p>0.05). The changes of cAMP content in CSF were similar to those in plasma, but the value of content in the acclimatization groups were higher obviously when compared with that in group 1. At Tr 42. 5°C, they tended to be lower (p>0.05) in group 3 and 4 as compared with those at Tr 41.5 °C , and were only 10% higher in group 4 than in group 1 (p>0.05). The content of cAMP in POAH changed in the opposite direction as compared with that in CSF. There were very obvious negative correlations among CSF and POAH cAMP contents (p<0.01). At Tr 42. 5°C > there was almost no difference between groups 4 and 1. The above data showed that after heat acclimatization (groups 3 and 4) , the duration of heat tolerance prolonged significantly;the changes of cAMP content in plasma, CSF amd POAH reflect the alleviation of the autonomic nervous reaction on heat stress, especially in the 16-day acclimatization group (group 4).The source of cAMP in CSF was related closely to its metabolism in POAH.
出处
《航天医学与医学工程》
CAS
CSCD
1992年第4期250-255,共6页
Space Medicine & Medical Engineering
关键词
热习服
热应激
自主神经系统
heat acclimatization, heat stress, autonomic nervous system, adenosine 3'5' cyclic phosphate
