The aim of the study was to evaluate the effect of β-endorphin on oxygen activity of polimorphonuclear neutrophils and to investigate the total antioxidant status of blood serum in rats subjected to chronic treatment with methimazole. The study was carried out on 15 male Wistar rats weighing 270-290 g, divided into two groups. The animals from experimental group were administered a 0.05% drinking water solution of methimazole. The oxygen activity of peripheral blood neutrophils was examined using a modified RBA test. The extra-receptor effect of β-endorphin on the respiratory burst of neutrophils was evaluated. The incubation of neutrophils in the presence of phorbol myristate acetate (PMA) in the control group caused a nearly threefold increase in the oxygen activity of the cells compared to the control. Slightly higher values were obtained after addition of β-endorphin at the concentration of 10-6. Lower concentrations of this opioid (10-8 and 10-10) also stimulated oxygen activity but at a lower level than PMA. Naloxone did not affect the oxygen activity only when using β-endorphin in the concentration of 10-6. Naloxone and β-endorphin in the concentrations of 10-8 and 10-10 evoked a linear decrease in the oxygen activity of neutrophils, below the values obtained for PMA. The obtained results suggest that methimazole significantly modulates the generation of reactive oxygen species under the influence of β-endorphin, which stimulates the respiratory burst via the receptor pathway and inhibits it via the extra-cellular pathway. Methimazole also stimulates the anti-free radical defence.
The paper assesses the treatment of cutaneous fungal infection in young beef cattle caused by Trichophyton verrucosum using orally administered zinc sulphate for 28 d at 2 g per animal per day and subcutaneous application of 2.5 mg/kg levamisole administered three times every 7 d. The study was conducted on animals at the age of 110 to 122 d, which were divided into two experimental groups: group I (animals suffering from ringworm with low levels of zinc in serum) and group II (animals suffering from ringworm with normal levels of zinc in serum). The remaining animals (control group) were divided into three subgroups: K (clinically healthy animals, which had normal serum levels of zinc), KI (animals infected with ringworm and showing a reduced level of zinc), and KII (animals suffering from ringworm with normal serum zinc levels). During the study the following parameters were investigated: clinical signs of fungal infection, zinc content in serum, percentage of phagocytic cells, and phagocytic index. The symptoms of the disease were observed only in group II on day 56. In group I, an increase in the percentage of phagocytic cells was observed, as compared to the original values, on days 7, 21, and 56 and a fall in this parameter was noted on days 14 and 28. In group II, there was a decrease on day 14 and an increase in comparison to the original values, followed by a gradual fall till day 56 of the experiment. In group I, phagocytic index remained on a stable level till day 56 and in group II until day 28, and subsequently began to increase gradually. It was found that oral supplementation of zinc sulphate combined with nonspecific immunostimulation may be applied in fighting skin fungal infection in cattle, and that zinc and levamisole may exhibit synergism affecting the evolution of nonspecific immunity.
Introduction: Thyroid hormones affect protein turnover, and in the case of hypothyroidism a decrease in protein synthesis and reduced release of certain amino acids from skeletal muscles are observed. Changes in the amino acid system of skeletal muscles may be responsible for the occurrence of muscle disorders. Material and Methods: The study measured the content of selected amino acids in the gastrocnemius muscle of Wistar rats during experimental hypothyroidism induced by oral administration of methimazole at a concentration of 0.05% in drinking water for 90 d. The rats were divided into four groups: E1 (n = 6) - experimental males, E2 (n = 6) - experimental females, C1 (n = 6) - control males, and C2 (n = 6) control females. Results: A statistically significant reduction occurred in leucine, isoleucine, and 1-methylhistidine levels in males, and 1-methylhistidine in females, in comparison to the control groups. Conclusion: The hypothyroidism-induced changes in amino acid content may be responsible for the occurrence of skeletal muscle function disorders.
The aim of the study was to evaluate the effect of regular physical exercise on cortisol concentration and oxygen-dependent bactericidal activity of neutrophils in peripheral blood in recreational and competitive sport horses (racehorses - Ra, trotters - T, jumping horses - J, driving horses - D). The study was conducted on 55 clinically healthy horses. Blood samples were collected from the external jugular vein three times: before exercise, immediately after exercise, and after 30-min rest. Blood samples were subjected to haematological examination, cortisol concentration was determined by radioimmunoassay (RIA) and neutrophil oxygen metabolism of neutrophils was determined using a chemiluminescence method. The analysis showed that cortisol concentration was significantly higher (P<0.05) post-exercise only in the blood of sport horses. This finding, along with a significant correlation (P<0.00005) with the heart and respiratory rates, suggests that the magnitude of cortisol secretion is associated with the intensity and duration of exercise. The relatively small post-exercise increase in cortisol concentration during different exercises of horses resulted in a transient increase of chemiluminescence activity of neutrophils, mainly in D (P<0.00001) and J horses (P<0.01). In the studied groups analysis of the correlation between cortisol concentration and other parameters showed significant correlation only in the case of the CL total in T (P<0.02) and D horses (P<0.004). It is therefore apparent that in a limited concentration, this hormone may stimulate the activity of these cells, although the effect of other neurohormonal factors cannot be excluded. This result confirms that regular and moderate training loads have a beneficial effect on the immunological status of horses.
The objective of the study was to assess ratio of oxidation to antioxidation in the blood of horses in selected equine diseases. The study was conducted on 47 Polish half-breed horses (36 mares, six stallions, and five geldings) aged 2 to 16 years. Nineteen mares were diagnosed with endometritis, seven horses with symptoms of colic, and six with upper respiratory tract infection. The remaining clinically healthy horses (n=15) served as control. The following parameters were measured: oxygen metabolism in neutrophils using a chemiluminescence (CL) method, total antioxidant status (TAS) of blood plasma, as well as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activity in whole blood. The results demonstrate increased CL of neutrophils in mares with endometritis, as well as in horses with symptoms of colic. This finding was associated with decreased values of SOD, GPx, and TAS (chiefly in mares with endometritis), which suggests oxidative stress. These results underscore the importance of a broader use of oxidant/antioxidant status assessment in studies of the pathogenesis and pathomechanisms of equine diseases.
Introduction: Thyroid hormones play a major role in the regulation of testicular maturation and growth and in the control of Sertoli and Leydig cell functions in adulthood. When naturally occurring, hypothyroidism causes male hypogonadotropic hypogonadism and Sertoli cell function disorders, but when iatrogenic and methimazole-induced its influence on the pituitary-testicular axis function with respect to Sertoli cells is poorly known.
Material and Methods: Male adult Wistar rats (n = 14) were divided into two groups: E – taking methimazole orally for 60 days, and C – control animals. After 60 d, the concentrations in serum of testosterone, follicle-stimulating and luteinising hormones, and inhibins A and B were measured. Testicles were examined morphologically: the apoptotic Sertoli cell percentage (ASC%) and number of these cells functional per tubular mm2 (FSCN/Tmm2) were calculated.
Results: In group E, inhibin A was higher while inhibin B was lower than in group C. ASC% was higher and FSCN/Tmm2 lower in group E than in group C.
Conclusion: A specific modulation of Sertoli cell function in the course of methimazole-induced hypothyroidism leads to a simultaneous concentration increase in inhibin A and decrease in B. Inhibin A might share responsibility for pituitary-testicular axis dysfunction and hypogonadotropic hypogonadism in this model of hypothyroidism.
Methimazole-induced hypothyroidism is a clinical problem in the treatment of hyperthyroidism in people and animals and is an example of metabolic disease that can lead to fertility disorders and can give elastographic testicular changes.
Material and Methods
Ultrasound elastography using the Esaote MyLab Twice ultrasound system and a morphological examination of testes were performed in seven methimazole-administered (group E) and seven healthy rats (group C).
The elasticity ratio of strains in the scrotal wall of the near-field test area to testicular tissue (ELX-T-RAT) and hardness percentage of strained tissues in the defined area of a testicle (ELX-T%HRD) in group E were statistically significantly lower than in group C. The degree of spermatogenesis was statistically significantly higher in group E than in group C and similarly seminiferous tubule diameters in group E were statistically significantly higher than in group C. Body weight and testicular weight in group E were statistically significantly lower than in group C.
Changes in the elastographical parameters of testes may result from disorders secondary to hypothyroidism. The usefulness of elastography is noteworthy in the case of evaluation of testis function in patients with some metabolic disorders.
The paper describes the influence of oral administration of methimazole on biophysical skin parameters. Wistar rats of different sex (220-260 g) were used in the experiment. Biophysical skin parameters, such as transepidermal water loss (TEWL), corneometry, and pH were examined at seven-day intervals. Significant changes in the parameters were observed on the 7th d of methimazole administration. The changes were observed in both sex but males appeared to be less sensitive in that respect. Changes in the parameters in the females showed rapid mechanisms, which normalised transepidermal water loss and skin hydration, as well as restored skin barrier functions. TEWL, skin hydration, and skin pH measurements allow an early assessment of skin barrier dysfunction after administration of this drug.
The aim of the study was to demonstrate the orthodontic treatment of malocclusions in dogs, a condition which can lead to cranio-mandibular and functional disorders of the stomatognathic system. The treatment involved the use of maxillofacialorthopaedic appliances, which type depended on the type of disorder and the degree of malocclusion. The applied treatment induced changes in the alveolar bone. Throughout the process of the treatment a great attention was paid to regular brushing off the orthodontic appliance using antiseptics for prophylactic prevention of inflammation of gingival tissue and the palate caused by food getting stuck in the spaces between the teeth.