摘要
我国夏季气候炎热，影响人们的生活工作。许多高温生理的现象和本质、机体热适应机理、提高耐热能力的关键、高温慢性的胡害作用等方面的问题仍有待阐明，其中生产环境高温对机体损害机理与防治措施的研究，仍为当前国内外学者研究的热点。本题着重在热损害机理及防治措施方面进行研究。
This Paper reports on the mechanismof heat injuries and pretective measuresfor working in hot environments. 1, It isconsidered unnecessary to separate sunstrokefrom heat stroke, thus heat apoplexy can beclassified into heat stroke (including sunstro-ke), heat-cramp and heat-exhaustion, whichis resulted from disorders in vascular constri-ction-dilitation regulation. The principles fortreatment and employment prohibition aresuggested; 2, It is concluded that inhibitionof stomach movement by heat is caused bythe action of sympathetic nerves on α-andβ-adenotropic receptors in stomach muscles,and such, inhibitions can be relieved by α-orβ-receptor blockage agents or beverage withsimilar effects; 3, Heat stress may causehypoxic damage to cells, reducton of SODactivity, decrease in the synthesis of PGI2,change in hemorrheology and disorder in lipidmetabolism, which enhances atherosclerosisby β-VLDL. Therefore, low lipid food forheat exposed workers are suggested; 4, Heatinduces the synthesis of a new group ofproteins (HSPs), with a molecular weight of70 kD (70 kD family), isoelectric point of 5～7. The amount of HSPs synthesis is relatedto the intensity, and duration of heat expo-sure. During 1 hour exposure to lethaltemperature (43℃, a transient increase inHSPs synthesis followed by a sharp decreasein HSPs synthesis, decrease in surviving cellsand increase in cellular permeability occured.Some irreversible changes, such as swellingand degranulation of endoplasmic riticulum,loss of mitochondria ridge and nucleonuscould be observed under electron-microscope,indicating the system for protein synthesisand the related stress responses were damagedby heat. Such damages took place inmembrane proteins. However, when cellsacclimatized to heat after be pretreated with37℃ were exposed to lethal temperature(43℃); their HSPs Synthesis increased andremained at high level for a longer time,their survival rate increased from 4% to 83%,and their LD prolonged (24 min to 40 min).Incorporation of H-glutamic acid in HSPscould also be found. At the same time,permeability of cellular membrane and lipidperoxidation were markedly lower than onnon-pretreated cells. Less severe damagecould also be proved by electron-microscopy.Further experiments were also carried out topurify HSPs and analyze their amino acid se-quences, which makes it possible to apply HSPsfor the health monitoring of heat-exposedworkers or improving heat tolerance of theworkers by adding some amino acids necessaryfor HSPs synthesis into beverage or food forsuch workers; 5, Standard for comprehensi-vely evaluating hot workihg environments andthe necessary methods and instrument arestudied or suggested.
出处
《中国工业医学杂志》
CAS
1991年第2期34-36,共3页
Chinese Journal of Industrial Medicine
