Medicine/8.Morphology
Ulyanov V.O.
The influence of chronic stress on the uterine contractile activity
An g-irradiation
in small doses and socio-economic terms negatively influence on the reproductive
system. They increase the amount of cases of uterine contractile activity violations.
The mechanisms of influence of radiation and stress on uterine contractile
activity are not investigated enough.
Research purpose: to investigate the
influence of g-irradiation and chronic emotionally pain stress on contractile activity
of uterus in an experiment.
Experimental researches are conducted on the
adult female of rats of Vistar line. Animals were subdivided in two groups. In
the first group of animals was the chronic emotionally pain stress designed. In
the second group the chronic emotionally pain stress after g-irradiation in a
total dose 1,0 Gy was designed. Adult intact unpregnant females made the group
of comparison.
Animals were taken from an experiment on the
third, tenth and seventeenth days of chronic stress model. It conforms to the
stages of alarm, stage of resistance and exhaustion of chronic stress. In a myometrium the activity of
acetylcholinesterase was investigated.
Contractile activity of uterus was researched in vitro on the isolated
preparations of the myometrium smooth muscles. The duration of contraction,
duration of intervals between contractions, maximal amplitude of contraction,
frequency of contractions per 10 minutes of observation were analyzed.
It is revealed as a result of the conducted
researches, that contractile activity of uterus does not change on the stage of
alarm and stage of resistance of chronic stress. Duration of myometrium contraction a diminishes on
21,4%, an interval between contractions increases on 20,2%, amplitude
diminishes on 27,6% on the stage of exhaustion of chronic stress. Frequency of contractions
does not change.
The duration of contractions, interval
between them and amplitude of contractions change on the stage of alarm of
chronic stress in the second group of observation. On the stage of resistance of chronic stress the duration and amplitude of contraction
approach the indexes of the first group. But duration of interval between contractions
remains greater on 30,5%, and frequency of contractions is less on 13,9% than
in the first experimental group.
It is revealed as a result of the conducted
researches, that the animals of the first group on the stage of alarm of
chronic stress did not have changes of activity of acetylcholinesterase in a
myometrium. Activity of acetylcholinesterase grew on the stage
of resistance of chronic stress on 23%,
comparatively with intact animals. It is the sign of violation of synaptic
transmission of nervous impulse. On the stage of exhaustion there was
oppressing activity of acetylcholinesterase. It is the sign of exhaustion of
the acetylcholine-acetylcholinesterase system. The changes of activity of
enzyme were accompanied with disorders of contractile activity a myometrium.
In the
second experimental group the activity of acetylcholinesterase changed already
on the stage of alarm of chronic stress. It was accompanied in the disorders of
contractile activity of uterus. On the stage of
resistance the activity of
acetylcholinesterase remained stable. On the stage of exhaustion the oppressing
its activity on 33,5% comparatively with intact animals and on 16,6%
comparatively with the first experimental group found out. The changes of
activity of acetylcholinesterase on the stage of exhaustion of chronic stress
in the second experimental group conforms to the maximal disorders of
contractile activity of the myometrium.
Conclusions.
Chronic
emotionally pain stress causes disorders of contractile activity of uterus.
Duration of contraction a myometrium diminishes, intervals between contractions
increase and amplitude of contractions
goes down.
The design of chronic emotionally pain stress
after total g-irradiation deepens the disorders of contractile activity of uterus.
An g-radiation and chronic stress violate the activity
of acetylcholinesterase in a myometrium. It causes the violation of contractile
activity of the uterus.