An investigation into the effect of hypokinesia on the ribonucleic acid (RNA) content, the nucleotide composition, and dynamics of protein content in the motoneuron of the rat spinal cord anterior horns is described. Methodology and findings are presented. The study results showed that the nucleotide composition of the total cellular RNA at all the studied periods of hypokinesia remained unchanged and is characteristic for the cytoplasmic, high polymer ribosomal RNA. This means that with a change in the functional state of the neuron the newly formed RNA of the nerve cell has the same composition of bases as the original RNA that belongs to the ribosomal type

Gorbunova, A. V.

English

NASA Technical Reports Server

NASA TECHNICAL MEMORANDUM NASA TH-76190
 
EFFECT OF RESTRICTED MOBILITY ON RNA CONTENT
 
AND NUCLEOTIDE COMPOSITION AND ON PROTEIN CON-

TENT IN MOTONEURONS OF SPINAL CORD ANTERIOR HORNS
 
A. V. Gorbunova.
 
Translation of "Vliyaniye ogranicheniya podvizhnosti na soderzhaniye
 
i nukleotidnyy sostav RNK i n soderzhaniye belka v motoneuronakh
 
perednykh rogov spinnogo mozga", Doklady AkademiA Nauk SSSR., Vol. 199,
 
976
No. 4, 1971, pp. - 979
 
(NASA-TM-76190), EFFECT OF RESTRICTED N80-29025 
MOILITY. ON RNA CONTENT AND NUCLEOTIDE 
d OPOSITION AND ON PROTEIN CONTENT IN RNO 
" 
 Unclas
MOTONEURONS OF SPINAL CORD ANTERIOR HORNS 

(National ,Aeonautics and Space .. ... G3/522-898
 
L 

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION '
 
WASHINGTON, D. C. 20546 JUNE 1980 .O
 
https://ntrs.nasa.gov/search.jsp?R=19800020524 2020-03-21T17:46:42+00:00Z
STANOAPD TITLE PAGE 
1. Rcort No. f2. Govornnont Accossion No. 3. R ,cipent':Cotalo 9 N. NASA TM-761901
 
4. Tul and Subrir. k 5. Repot Dote
 
t JUNE 1980
EFFECT OF RESTRICTED MOBILITY ON RNA CONTENT AND 

NUCLEOTIDE COMPOSITION AND ON PROTEIN CONTENT IN 6. PefomIng o0rganixokon Cod,
 
MflTflgu~NETg fly CPTflAT, CfRn AxTU.PTAPT N.-P 1 
7. Author(s) a. Powfoiming Orgonriation R ,pot110 . 
A. V. Gorbun6va 
 10. Work Unit Ho. 
11. Contract ar Giant N4o. 
9. Peforr.n , No.* cd Add,ost NASw- 3198Ogn.alion 
SC ITPA.N 13. Typo of Roport .nd Period Covrd 
Box 5456
 
ATranslation
 
i2 S orng A N.,o odnAddrss2n oncy 
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aional Aeronautics and Space Administration
 
Wasnington, D.C. 20546 14. Sponaoing Agency Cao
 
15. Luppbornontory Notes 
Translation of "Vliyaniye ogranicheniya podvizhnosti na soderzhaniye i 
nukleotidnyy sostav RNK i n soderihaniye belka v motoneuronakh perednykh 
rogov spinnogo mozga", Doklady Akademii Nauk SSSR, Vol. 199, No. 4, 
1971, pp 976-979
 
This article describes an investigation into the effect of hypokinesia
 
on the RNA content, the nucleotide composition and dynamics of protein
 
content in the motoneuron of the rat spinal cord anterior horns. Method­
jology and findings are presented. The smiiay reults sh&wedthat U11eJ
 
nucleotide composition of the total cellular RNA at all the studied
 
periods of hypokinesia remained unchanged (table 2) and is characteristic
 
for the cytoplasmic, high polymer ribosomal RNA. This means that with a
 
change in the functional state of the neuron the newly formed RNA of the
 
nerve cell has the same composition of bases as the original RNA that
 
belongs to the ribosomal type.
 
One figure, 2 tables, 12 references are included in the five pages.
 
17. Key Words (Sclected by Author(s)) 18. oltributlon Statoment 
Unclassified - Unlimited
 
19. Socunty Cassif. ( this rprt) 23. Soti'ty Cletoif. (of this PofLo) 21. No. of Polo P "ifo"f 

Unclaaified Uncles31fied 7 
i 
UDC 591.18 
EFFECT OF RESTRICTED NOBIITY ON RNA CONTENT 
AND NUCIEOTIDE COMPOSITION AND ON PROTEIN 
CONTENT IN MOTONEUONS OF SPINAL CORD ANTERIOR 
HORNS 
A By
 
A. V. Goibunova* 
Reduced motot activity always leads to a change in the functioning of many /976"* 
physiological systems in the organism of man and animals [1-3]. The propxio­
ceptive and interoceptive impulses coming from these systems to the central 
nervous system axe an indispensable condition for the normal functioning of the 
nerve tissue, and consequently, the normal occurrence of its metabolism. 
A large amount of data has been accumulated that indicates that the prolonged 
stay of the human organism in a state of hypokinesia results in a number of func­
tional disorders in the nervous system E4,5]. There is information on a disruption 
in the cellular metabolism of the nervous system duxing restricted mobility [?,6]. 
Since the link between the functional activity of the cell and the metabolism of
 
of RNA and lzotein in it [7,8] has been noted repeatedly in the literature itcwas 
important to investigate the effect of hypokinesia on the RNA content and nucleotide 
composition, as well as on the dynamics of protein content in the motoneuron of 
the rat spinal cord anterior horns. 
The experiments were conducted on 35 mongrel albino male rats weighing 260­
300 g. The animals were placed in individual, special small-sized cages. Such 
Institute of Medical and Biological Problems, -USSR Ministry of Public Health 
Numbers in margin indicate pagination in original foreign text. 
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Figure 1. 	 Change in RNTA Content (a) and Protein Content (b) in lMotoneurons of 
Spinal Cord Anterior Horns of Rat at Different Periods of Hypokinesia 
1--control; 2--experiment 
cages sharply restricted the movements of the animal, however, without complete /977 
immobilization. Conditions were created under which even the prolonged stay of 
the animals in the cages did not lead to the development of chafings, bedsores
 
and disorder in the integrity of the integument. Thirty-five rats kept under 
vivarium conditions served as the control. The spinal cord at the level of the
 
intumescentia lumbalis was taken for study from the experimental and control 
animals at 	the same time on the 1st, 3rd, 5th, 7th, 10th, 14th and 30th day of the
 
experiment. Fragments of the spinal cord 2-3 mm in size were fixed in Cainua's 
solution for 1 hour and poured into paraffin. The motoneurons of the spinal cord 
anterior horns were isolated from sections 60 p thick with the help of a Fonbryun
 
micromanipulator under control of a MBI-3 microscope. The RNA content and nucleo­
tide iomposition in the isolated cells were determined according to the Edstrom 
method [9]. The RNA content in an individual cells was computed by the Slagel and 
Edstrom method [10]. Every average amount of RNA content in the cell was 
determined from the results of analyzing 50-60 cells taken f om 4-5 animals. 
Groups of 4-5 neurons were used for electrophoretic separation of nucleotides. 
The dry cellular weight was determined by the method of interferometry [8] 
on sections 7 p thick. Since under conditions of a fixed prepaxation the content 
of dense substances is protein for more than 80% of the dry weight, the method 
2
 
TABLE j.* CHANGE IN PROTEIN CONTENT IN NOTONEURONS OF RAT SPINAL CORD ANTERIOR 
HORNS WITH RESTRICTED MOBILITY, 4gg 
_ Experiment Control 
1st day 1706+69 1721+71 
3rd day 111?41 1733t58 
D 0.01 -
5th day 180o+68 1 2133+85 
D . 0.05 
7th day 1960+78 200871 
14th day 1966T95 1971+84 
30th day 1 98;F126 1996+-138 
Data for three animals and 90 measurements 
of intexferometry has become popular as a means of determining the total cellular 
protein. 
All the numerical material was processed by the method of variational 
statistics according to Student-Fisher. 
Changes in the RNA content were noted already on the first day after the 
beginning of the experiment, which lasted up to the 5th day tibclusively. At 
later periods,-aall the way up to Ahe 30th day of restricted mobility, no changes 
were observed in the BNA content in the motone~ons, (fig. l, a). 
Analysis of the changes in the protein content in the motoneuron cytoplasm 
indicated that hypokinesia was accompanied by a considerable reduction in the 
protein content in the nerve cell cytoplasm on the 3rd and 5th day of the experi­
ment; no reliable changes were noted in the protein content in the remaining 
periods (fig. l,b, table 1). 
Analysis of the behavior of the an{als during the experiment demonstrated 
that in the experiments with hypokinesia two phases were noted in the motor 
activity. The first phase lasts 1-5 days and is characterized by a striving by 
the animal to free itself of the unaccustomed conditions, which in our experimental 
conditions was accompanied by an increase in the motor activity. Further the 
animals seemingly become accustomed to the new conditions of existence. The
 
high motor activity of the animals in the period of the first to fifth days of 
the experiment, apparently, can be appraised as the cause of the reduction in the 
RNA content in the motoneurons of the spinal cord, and can be qualified as the 
3 
"cytochemical equivalent of high functional stress and even overexcitation of 
these structures" [I]. This is the more likely since there -<is. published infor­
mation on the link between the function acti-zv-y- of the cell and the RNA content 
in it [7,8,11]. Further, by the seventh day of the experiment, the animals adapt /978 
to the conditions of hypokinesia, i.e., a state occurs in which catabolism and 
anabolism of RNA are well balanced with each other on a new level corresponding 
to hypokinesia; as a consequence of this no changes are observed in the RNA content.
 
TABLE 2. NUCLEOTIDE COF0SITION OF RNA IN XOTONEURONS OF BAT SPINAL CORD AT 
DIFFERENT PERIODS OF HYPOKINESIA 
No. of No. of Oelative content of purine and pyrmidine bases, 
animals analysesnolax ratios in % 
Control .. ......
 
1st day 1 3 30 21,9:0,96 37,4±0,966 22,8+1,01 17,9±0,94 ,

30th day ,3 - 30 21,53±I,07 36,9-0,96 22,8±0,73 18,7±0,75

ist dayn 3 30 21,6±-0,92 37,4;L1,09 22,7-1, ,0832+1,15
1sd day / 3 30 21,35±0,99 37,1±1, 22,8+0,954 18,7±=,84
3rd day 3 30 21,26+1,0 37,2+ 131 23,2±t,11 "18',4+0 911
Oth day 3 30 22,06±-1,03 36,2+0 92 23,2+0,88 18,6±0,887

14th day 3 30 21,9±0,79 36,6±0,883 23,02±0,94 18,9±0,79

14th day 30 21,3.0,94 37,1±0,87 23,2±0,85 18,2-'0,78
30th day 
Protein metabolism in the nerve cell is characterized by the same features as 
RNA metabolism, and namely its functional lability. Here both the biochemical 
and the cytochemical studies show that with excitation of the nerve cells intensi­
fied protein synthesis occurs in them; with the onset of overexcitation and 
exhaustion of the nervous system a breakdown of protein molecUles begins to 
dominate, as a result of which the protein content is reduced [11, 12]. The 
reduction in the total cytoplasmic protein in the motoneurons df the spinal 
cord anterior horns obtained under conditions of hypokinesia on the 3.5 day of the 
experiment, apparently, can be explained by the occurring fatigue of the neurons 
induced by the high motor activity in this'period. 
Changes in the RNA content under conditions of our experiments were accompanied 
by analogous~ehanges-4!n ,the,,l.otein content that were somewhat lagging in time, 
which confirms the link between RNA and protein synthesis in the cell, 
Since the detected shifts in the RNA content during hy-pokinesia are apparently 
a reflection of the qualitative changes in the RNA molecules, we undertook a 
4 
study of the qualitative nucleotide composition off.the total cellular RNA at all
 
the studied periods of hypokinesia. The study results showed that the nucleotide
 
composition of the total cellular RNA at all the studied periods of hyyokinesia
 
remained unchanged (tab'le 2) and is-: characteristic for the cytoplasmic, high­
polymer ribosomal RNA. This means that with a change in the functional state of 
the neuron the newly formed RNA of the nerve cell has the same .composition of bases 
as the original RNA that belongs to the ribosomal type.
 
The author is deeply grateful to V. Ya. Brodskiy and N. V. Nechayeva for 
help in working on the interference microscope and assistance rendexed during work 
on the microscope and in processing the obtained data.
 
References
 
1. Katkovskiy, B. S. Kosmich. biol. i med 1, 5, 67 (1967). 

2. Portugalov,; Gazenko, 0. G.; et al., Kosmich. biol. i med., 1, 6, 18 (1967). 
3. Fedorov, I. V.; Milov, Yu. I.; et al., Kosmich. biol. i med., 2,1,?? (1968).
 
4. 	 Gerd, M. A. in Aviats. i kosmich. med ["Aviation and Space Medicine"], 
Moscow, 1963, p.T1-2-6-. 
5. Krupina, TJ N.; Tizul, A. Ya.; et al., Kosmich. biol. i med., 1,5,61 (1967). 
6. Brumberg, V. A.; Pevzner, L. Z. Tsitologiya, 10, 11, 1452(1968).
 
7. Pevzner, 1. Z. Ukr. biokhim. zhurn., 35, 3,448 (1963). 
8. Brodskiy, V. Ya., Trofika kletki ["Cellular Trophism"], Moscow, 1966. 
9. Edstrom, J. in Methods in Cell Physiology, 1, 1964, p. 417. 
10. Slagel, L; and Edstrom, J. J. Cell. Biol., 34, 395 (1967),
 
11. 	Hyden, H. Acta Physiol. Scand., 6, Suppl. 17 (1943). 
12. 	 Palladin, A. V. III Vsesoyuzn. konfer. p biokhimii nervno sisteny ["Third 
All-Union Conf. on Biochemistry of the Nervous System"j, Yerevan, 1963. 
5
 
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Effect of restricted mobility on RNA content and nucleotide composition and on protein content in motoneurons of spinal cord anterior horns

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