The aim of this study was to investigate the influence of metabolic cage housing on the Wistar rat physiological state and to analyze the correlation between the minerals in blood and urine. Thirty male rats were used in the experiment. Fifteen rats (control group) were housed individually in standard polycarbonate cages and fifteen rats (experimental group) in metabolic cages (Techniplast, Italy) for two weeks. Body weight, respiration rate, water and food consumptions were recorded for each animal at the beginning of the experiment. The same parameters, as well as blood and urine parameters of control and experimental animals were recorded during the experiment after 72 h, 168 h and 336 h of housing in standard cages and metabolic cages. Urine collection was measured only in the experimental group. Rats weight decreased from 3.84 % to 18.59 % (P<0.05), respiration rate from 18.65 % to 24.59 % (P<0.05) when rats were housed in metabolic cages. Consumption of food and water by the rat depended on how long the animal was kept in metabolic cage. Glucose concentration increased on average by 15.37 %, WBC count decreased by 5.83 % in the blood of rats housed in metabolic cages compared to the animals housed in standard cages. We did not observe significant changes of triglycerides concentration, red blood cells count and total protein between all rats. The positive moderate correlation of rat housing in a metabolic cage was between K blood and K urine, P blood and P urine, Na blood and K blood, between Na urine and P urine and significant negative moderate correlation was determined between K urine and P urine. These present study findings indicate that metabolism cage housing significantly affects rat’s physiological parameters and potentially may influence animal health and wellbeing.
Mobile phones (MP) and other electronic and communication devices that are used daily expose users to electromagnetic fields (EMF) and contribute to an increasing incidence of neurological disorders. Brain tissue is the closest organ to the MP as it operates, thus the influence of MP radiation on brain tissue is of particular concern, although research is still inconclusive. The present study investigated the possible effect of an EMF (1,350–1,375 megahertz (MHz)) from an MP on morphological and histopathological profiles in the mouse brain.
Material and methods
Healthy BALB/c mice were assigned to three equal groups (a control and two experimental groups, n = 10 each). Experimental mice were exposed to EMFs continuously for 72 h, those of experimental group I to a 1,350 MHz field at a specific absorption rate (SAR) of 4.0 W/kg, and group II to a 1,375 MHz field EMF at an SAR of 4.0 W/kg. Brain segmentation and histopathological analysis were applied to detect changes in the morphometric parameters of the brain lobes and identify pathological lesions, respectively.
Histopathology results revealed shrinkage of pyramidal neurons, presence of mild perivascular and perineural oedema, and some vacuolation of neurons and glial cells derived from mouse great hemispheres. The lesions also included reduction of Purkinje cells, vacuolisation of neurons and glial cells, and interstitial oedema in the cerebellum.
MP distance of 3 cm from the cage may induce appreciable morphological changes in mouse brain structures; therefore, more comprehensive research is essential for assessment of safe distance. These pronounced effects may interfere with the results of laboratory tests on murine experimental models in veterinary or biomedical research.