The influence of immobilization on indices of stress reaction in rats and dogs

The experiment simulated the stress reaction, using markers of hidden functional organism reserves. These markers were immobilization, carbocholine and saline. The study was carried out on male rats weighing 180-240 g and dogs weighing 15-22 kg. Immobilization of the rats was performed once a day for 18 hours, fixing on the back by all the limbs on the operating table, the dogs were placed in a narrow cage of the wooden slats. Non-selective cholinomimetic carbocholine ("Reanal", Hungary) was administered intramuscularly to rats at a dose of 25 mg/kg, the dogs - 6 mg/kg. Physiologic saline was administered intraperitoneally to rats in a volume of 1 ml per 200 g body weight, dogs - intravenously in a volume of 1 ml per 10 kg bodyweight. Blood for laboratory tests was taken from an artery in rats during decapitation, in dogs - from the subcutaneous vein of the shin. The intensity of the stress-reaction is determined by such criteria as the level change of 11-oksicorticosteroids (11-OCS) in plasma, as well as the total content of leukocytes and the leukocytal formula in peripheral blood in dogs and rats. Statistical procedures were performed with the help of StatSoft STATISTICA 6.0 application package using the average values of the analyzed indicator (M), standard error of the mean (m), the criterion of Mann-Whitney (U-test) and Student's t-test (t). The differences were considered significant at p<0,05. As a result, we obtained the adaptive response of different types with a characteristic set of changes in blood parameters. Using a different interval of time between the injections of saline and carbochol, changes in the concentration of corticosterone in rats were obtained after immobilization, as well as neutrophilia (due to the segmented neutrophils), monocytopeniya and lymphopenia. In the animals, the most striking changes in blood were observed with the simultaneous combination of saline and carbochol. In dogs, the results were obtained which indicated the dependence of the blood and the direction of change after the action of immobilization on the baseline indicators. Thus, in animals with low baseline levels 11-OCS an increase in hormones in plasma after stress is more pronounced than in the group of animals which have higher level control 11-OCS. Changes of leukogram after immobilization consisted of a pronounced neutrophilia (due to the segmented forms in animals with initially high content of band neutrophils and due to the stab forms in animals with initially low level of their content), monocytosis and lymphopenia. Basophils were detected only in the first group of animals and their number increased after the immobilization. The number of eosinophils decreased in the group of dogs with initially high level of eosinophils and increased in animals that had low baseline level of eosinophils.After immobilization, in animals with a low baseline of stab neutrophils, eosinophils, monocytes and with initially high content of lymphocytes, the level of numerical values of eosinophils, monocytes and lymphocytes was higher and the content of stab neutrophils was lower than in the other group of dogs.

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