Аннотация:Pregnant women are considered to be the most vulnerable
part of society subjected to stress conditions. The effects
of acute stress occurring in the early stages of gestation in
the development of pregnancy are of particular interest, for
early gestational disturbances may interfere in the normal
development of pregnancy or result in perinatal pathology
including premature birth and even spontaneous abortion.
Premature birth is the major source of perinatal death
and disability. Furthermore the intrauterine health of the
baby is important for preventing certain adult diseases.
The aim of the present study was to evaluate the influence
of acute hypoxia (oxidative prenatal stress) on pregnancy
and offspring development.
White rats were subjected to acute hypobaric hypoxia
on the 9-10th day of pregnancy. The morphometric
characteristics of newborns were registered from P1 to
P60 period. The behavioral activity and the anxiety level
were investigated in 60-day-old rat pups using hole board
and elevated X-maze tests. The bioamines levels in brain
stem and cerebral cortex as well as morphometric analysis
of neuronal populations in CA1 and CA4 hippocampal
areas were determined using fluorescent and histological
methods, respectively.
Our studies indicated that low-resistant pregnant rats
(the first agonal inspiration was observed less than 5 rain
after the beginning of hypoxia) were at increased risk
for spontaneous abortion and for having a malformed
lower birth weight pups. And their offspring's Kettle index
remained significantly lower compared to control for at
least P60 period. Besides, prenatal hypoxia elicited many
disturbances which were manifested at and after birth.
60-day-old rats of both sexes demonstrated hypoactivity
and the decrease of orientative-training reactions whereas
young females were also less anxious. Thus acute
prenatal stress led to an increased level of emotional
and behavioral problems during development and in adult
age. Data obtained were in good agreement with observed
biochemical and histological changes: the general density
of neuronal populations in CA1 and CA4 hippocampal
areas was decreased in males and females, surviving
antenatal hypoxia. The total number of flee cells in both
areas did not change while the number of cells with
satellite glia decreased in both sexes. At the same time,
the number of morphologically changed cells in CA1
hippocampal area was significantly increased in males but
remained unchanged in females. The changes in bioamines
levels were also more expressed in males. Thus, NE and
DA levels were enhanced in both brain stem and cerebral
cortex in males whereas females demonstrated a significant
increase of brain stem DA level only.
Prenatal maternal stress affects pregnancy outcome
and results in early disturbances of brain functions with
changes in offspring's behavior.