The aim of this study was to detect the correlation between the change in the ambient temperature and adaptation of the pronephros – the main haematopoietic organ in fish, which so far has not been subject of research. Compared with other teleosts and their number of blood cells in peripheral blood, tench (Tinca tinca L. 1758) showed the corresponding trend of changes in number of pronephros haematopoietic cells after exposure to increased water temperature. The number of all haematopoietic cell lines was changed during the conditions of thermal stress (P<0.01; P<0.05). The number of erythroblasts was significantly reduced due to shift of haemoglobin curve of dissociation to the right. Leukopoietic cells were increased significantly as a response of pronephros to stress and all endocrine mediators of the stress (cortisol, leukine, etc.). The number of prothrombocytes was slightly decreased due to mobilisation into peripheral blood as in the case of cell precursor of monocytes. Eosinophilic and basophilic granuloblasts were not found in tench pronephros. Correlation (R) between body mass and total length was 0.526. Sex-specific variation of haematopoietic cells number in the same group was not observed (P>0.05), but it was significant between males or females among different groups (P<0.01; P<0.05 respectively).

Abstract Glyphosate is a pesticide that influences many blood parameters if taken orally or subcutaneously. This pesticide causes important changes in the metabolic activity which can be measured by organospecific enzyme activity such as liver aminotransferases (AST and ALT), while glucose acts as a stress, energy and metabolism indicator after acute glyphosate exposure. In this research, glyphosate was applied subcutaneously to rats, administrated each 24 hours for a 15 days period. The concentration of the applied glyphosate was 2.8 g/kg. The experimental rats were 13 weeks old. The concentration of serum glucose, the activity of lactate dehydrogenase and liver transaminases (AST and ALT) were observed as indicators of metabolic changes after treatment. It was observed that glyphosate led to a statistically significant decrease of serum glucose level. Statistically significantly increased (p<0.05) AST, ALT and LDH activities are indicators of hepatocyte damage while LDH activity demonstrates damage of other tissues.

Studies based on biochemical and hematological parameters in fish are significant in monitoring of health and early detection of pathological conditions. This research obtained values of serum electrolytes and hematological parameters in crucian carp (n = 15) and common carp (n = 13). Significantly different values of K, Cl and Ca concentration were detected. In serum of common carp there were significantly higher concentration of K and Cl and lower concentration of Ca, compared to the crucian carp. Hematological parameters differ in these two species. In blood of common carp significantly lower PCV, hemoglobin concentration, RBC and MCV and notably higher MCHC and WBC were obtained, compared to crucian carp. This preliminary research is important in establishing referential range of biochemical and hematological parameters in cyprinid fishes.

The effect of fluoride on the calcium level in serum was analyzed in the laboratory rat Rattus norvegicus. The control group consisted of 10, and the experimental group of 15 animals. In the experimental group, fluoride at a concentration of 3 mg/100 g body weight of rats was intramuscularly injected into the musculus gluteus maximus. The concentration of calcium was measured by the CPC method. The average serum calcium concentration was 2.46 mmol/l, with female rats having higher values of serum calcium than male rats. Fluoride caused the reduction of calcium concentration in serum (p<0.05); the reduction was significantly expressed in female rats (p<0.000).