【摘要】： 在航天失重（或“微重力”）環(huán)境停留可引起機體多個系統(tǒng)發(fā)生一 系列適應性改變和一些病理生理性變化。心血管失調（Cardiovascular deconditioning）及骨骼�。ㄌ貏e是抗重力�。┪s和肌力下降等均屬失重的 “不良影響”，不僅影響航天人員在空間的艙外活動能力，也可影響其返回再 入大氣層及著陸時的應急能力與安全。迄今已采用過的對抗措施有運動、企鵝 服、下體負壓（LBNP，Chibis服）、水鹽補充、抗荷服、營養(yǎng)、藥物及電流刺 激肌肉等。但基于運動的對抗措施尚存在效果局限、占時較長（2～4h/d）、消 耗物資與能源較多等缺點。為實現(xiàn)新世紀長時間“探險級”載人航天任務，采 用以人工重力為基礎的多系統(tǒng)對抗措施似是唯一出路。由短臂離心機實現(xiàn)的 “間斷性人工重力”（Intermittent artificial gravity, IAG）是設想中的 一種方案。但IAG最終可否用于航天實際，首先還必須闡明以下基本問題：① 間斷性人工重力對失重對心血管與骨骼肌等生理系統(tǒng)的不利影響是否具有全 面的對抗作用？②每晝夜所必需的最低有效G值、最短暴露時間、實施頻次， 究為多少合宜？③如何優(yōu)化間斷性人工重力方案及結合采取其他有關對抗措 施？ 為了回答第一個問題，我們以“尾部懸吊后肢卸荷大鼠模型”模擬失重 第四旱巨大學刃士學位論文 一 的生理影響，以叫5頭高位傾斜mUTL站立uTD）或離心機旋轉uM）？ 種方式模擬不同G值、不同作用方向的間斷性人工重力作用，并觀察其對后肢 骨骼肌萎縮與心肌收縮功能降低是否具有減輕／防止作用。實驗共分兩個部分： ①第一部分以肌肉的濕重，I、11型肌纖維橫截面積化SA）及 1型肌纖維比 例，以及毛細血管數(shù)／肌纖維數(shù)比值Co）為指標，觀察 HUT門 h川或。lh川＼ STD（lh／d、2 h／d或 4 h／d）或“N（l．5或 2．6－G；／lh／d）對 4周模擬夫 重大鼠后肢比目魚肌G L胖腸肌內與外側頭幾G與m）及趾長伸肌KI）l。） 的作用；蹈肌叩LA）與腔前肌門A）則僅從骨骼肌濕重變化進行了觀察。② 第二部分實驗以灌流乳頭肌的等長收縮與時程參數(shù)為指標，觀察釘D門卜小 2 h／d或 4 h川）對 4周模擬失重大鼠心肌收縮性能降低是否具有對抗作用。 同時還對三種模擬間斷性人工重力大鼠模型的一般狀況，特別是生長曲線／腎 上腺及睪丸濕重的變化進行了比較。 本工作的主要發(fā)現(xiàn)如下： 1 一般狀況 4周模擬實驗期間，模擬失重組GUS）體重增長與問步 ＄r 照組u）無顯著差別；但各種對抗措施對體重增長均有一定影響，尤以 SUS＋HUT（4 h／d）及“S＋CEN（2．6G／h．d）組為甚。模擬實驗 4周后，各鄉(xiāng) 大 鼠腎上腺濕重均與CON無顯著差別，表明大鼠所受到的一般性應激較�。坏� 組睪丸濕重均較CON顯著降低，且各組間無顯著差別。 2對抗后肢骨骼肌萎縮變化的效果 2．l 模擬失重4周后，除TA外，其余5種肌肉的濕重或相對重量均顯 著降低，其中以慢肌纖維為主的SOL及MG的萎縮程度明顯大于以快肌纖維為 主的 PLA及 EDL；各骨骼肌 1型肌纖維 CSA的減小最為顯著，11型肌纖維 C“ 除EDL外余均顯著減小。 2．2從肌肉重量變化看：每日不同時間的站立、何5”頭高位傾斜或離心 IV ／ 1 第四軍巨大學刃士學位論文 一 機轉動對SOL濕重的減輕變化均有隨作用時間延長而加大的顯著對抗效果；對 TA以外其余各骨骼肌，，只有相對重量的減輕變化顯示隨作用時間而加大的顯 著對抗效果。4 h川的站立或頭高位傾斜已可完全防止模擬失重大鼠各骨骼肌 相對重量的減輕變化。 2．3 從肌纖維變化看：2 h／d、4 h川的站立或＋45“頭高位傾＄1基本葉 防止各骨骼肌 1、11型肌纖維 CSA減小，I型肌纖維比例下降及 C八比值的變 化。 2．4 G值增大對抗效果反而
[Abstract]:Stopping in space weightlessness (or "microgravity") can cause multiple systems in the body to occur.
A series of adaptive changes and some pathophysiological changes. Cardiovascular disorders (Cardiovascular
Deconditioning) and skeletal muscle (especially the anti gravity muscle) atrophy and muscle strength decline are all weightlessness.
"Adverse effects" not only affect astronauts' ability to extravehicular activity in space, but also affect their return.
The ability to enter the atmosphere and to respond to landings. Safety measures have been adopted so far.
Clothes, LBNP (Chibis), water and salt supplement, anti G suit, nutrition, medicine and electric current.
Muscle resistance and so on. However, the motion based countermeasures still have limited effect, and occupy a longer time (2 ~ 4h/d).
There are many disadvantages, such as material and energy consumption. In order to achieve the "expedition stage" manned spaceflight mission in the new century, we have to take the task of "Exploring" manned space missions in the new century.
The multi system countermeasure based on artificial gravity seems to be the only way out. It is realized by a short arm centrifuge.
Intermittent artificial gravity (IAG) is conceived.
A scheme. But whether IAG can eventually be applied to aerospace reality, we must first clarify the following basic problems:
Does intermittent artificial gravity have all the negative effects of weightlessness on physiological systems such as cardiovascular and skeletal muscles?
2. The minimum effective G value, the shortest exposure time and the frequency of implementation necessary for each day and night.
How appropriate is it? Third, how to optimize the intermittent artificial gravity scheme and take other countermeasures.
Shi?
To answer the first question, we simulated weightlessness with the tail suspended rat model.
Fourth Yoshi University's Blade
One
Physiological effects, called 5 head tilt mUTL standing uTD) or centrifuge rotating uM?
The intermittent artificial gravity with different G values and different directions of action was simulated, and the hindlimb was observed.
Whether skeletal muscle atrophy and myocardial systolic function decrease can be alleviated or prevented. The experiment is divided into two parts.
(1) the wet weight of the muscle, the cross-sectional area of I, type 11 muscle fibers and the ratio of type 1 to muscle fiber were used in the first part of the SA.
For example, the ratio of capillaries / muscle fibers to Co was taken as an index, and HUT gate h Chuan or.Lh Chuan] was observed.
STD (LH / D, 2 h / D or 4 h / D) or N (l.5 or 2. 6 g / LH / D) for 4 weeks simulation husband.
Major hind leg soleus muscles G L fat intestines and lateral m G and m) and extensor digitorum longus extensor muscle L.
The effect of LA on the muscle and A of the anterior chamber muscle was observed only from the change of the wet weight of skeletal muscle.
In the second part, we measured the isometric and time parameters of papillary muscles, and observed the D.
2 h / D or 4 h Chuan) had antagonistic effect on the cardiac contractility of 4 week simulated weightlessness rats.
At the same time, the general situation of three simulated intermittent artificial gravity rat models, especially the growth curve / kidney, was also discussed.
The changes in wet weight of the upper glands and testicles were compared.
The main findings of this work are as follows:
1 general condition 4 week simulation period, simulated loss of reorganization GUS) weight gain and ask step R
There was no significant difference in group u, but all kinds of countermeasures had a certain effect on weight gain.
SUS + HUT (4 h / D) and "S + CEN (2.6G / H.D) group" were very simulated. After 4 weeks of simulation test, all the townships
There was no significant difference in wet weight between adrenal glands and CON, indicating that the general stress of rats was smaller.
The wet weight of testis was significantly lower than that of CON, and there was no significant difference between groups.
Effect of 2 antagonism on the changes of skeletal muscle atrophy in the hind limbs
After 2.l simulated weightlessness for 4 weeks, except for TA, the wet weight or relative weight of the other 5 muscles were obvious.
The SOL and MG atrophy of slow muscle fibers were significantly larger than those of fast muscle fibers.
The main PLA and EDL; the CSA of skeletal muscle 1 type muscle fibers decreased most significantly; type 11 muscle fiber C "
Except for EDL, all of them decreased significantly.
2.2 from the change of muscle weight: standing at different times of day, "5" head tilt or centrifugation.
IV
/
One
The Fourth Army's great university's Blade
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The effect of rotation on the wet weight of SOL increased significantly with the prolongation of the time.
The reduction in relative weight of all skeletal muscle other than TA showed a significant increase with time.
The antagonism effect of.4 h Chuan's standing or head tilt can completely prevent skeletal muscle in simulated weightlessness rats.
A reduction in relative weight.
2.3 from the change of muscle fiber: 2 h / D, 4 h Sichuan standing or + 45 "head high tilt $1 Basic leaf."
Prevent the decrease of 1,11 type muscle fiber CSA, the decrease of I type muscle fiber ratio and the change of C eight ratio.
Change.
2.4 G value increases antagonism
【學位授予單位】：第四軍醫(yī)大學
【學位級別】：碩士
【學位授予年份】：2001
【分類號】：R852.22

【引證文獻】

相關碩士學位論文 前1條

1 郭樹攀;冬眠陣與達烏爾黃鼠冬眠期抗廢用性肌萎縮機制的關系探討[D];西北大學;2010年

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