A.N. Fedchenko, L.E. Belyaeva, S.S. Lazuko, I.V. Ligetskaya, E.I. Kovzova
Allostatic load on pregnant rats and the peculiarities of coronary vessels tone regulation of their puberal offsprings
Educational Establishment «Vitebsk State Order of Peoples’ Friendship Medical University», Vitebsk, Republic of Belarus
Abstract.
Objectives. To determine the influence of different stressors on pregnant rats, on coronary vessels autoregulation of their puberal offsprings for the subsequent search for the methods to correct possible disorders.
Material and methods. Experiments were conducted on 40 white mongrel Rattus Muridae weighing 200-250 g and their offsprings. The model of chronic unpredictable stress included: (1) food deprivation during one day with the provision of free access to water on the 2nd, the 9th and the 16th days of pregnancy; (2) upright immobilization of rats in the plastic box filled with water (t=23±2C°) up to the level of the neck during 20 minutes on the 4th and the 11th days of pregnancy; (3) the imitation of a predator presence (contact with Felis excrements during one day) on the 6th and the 13th days of pregnancy. Coronary vessels autoregulation of the 3-month offsprings (14 rats born of mothers belonging to the «stress» group and 26 rats born of mothers of the «control» group) was studied on the isolated by Langendorff method heart which was perfused with standard Krebs-Henseleit solution.
Results. In mature males, whose mothers experienced allostatic load during pregnancy, the volume velocity of coronary flow (VVCF) increased by 17%, while the autoregulation index (AI) of coronary vessels decreased by 50,0 and 38,2% only during the elevation of the perfusion pressure (PP) from 80 to 100 and from 100 to 120 mm Hg, respectively, compared with the values acquired in the male offsprings, whose mothers pregnancy was normal. AI of female offsprings, which were born of rats exposed to chronic unpredictable stress during their pregnancy, decreased by 34% only during the elevation of the PP from 40 to 60 mm Hg, and coronary dilating reserve (CDR) was lower by 9,8% when the PP equaled 40 mm Hg, compared with the values acquired in the group of females that did not experience the action of stressors in the prenatal period.
Conclusions. Allostatic load during pregnancy results in the decreased coronary vessels tone autoregulation of the isolated heart of rats’ mature offsprings which may interfere with the adaptive capabilities of the heart and the whole organism. The obtained data may be used while conducting further experiments aimed at the investigation of new ways for the prevention and correction of the sequelae of prenatal stress.
Key words: allostatic load, autoregulation of coronary vessels.
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