Ivari ciklus során bekövetkező hormonális változások hatása a szérum leptin szint változására szuka kutyában
The hormone called leptin is mainly produced by white fat cells and could be important as a marker for determining the grade of obesity. It´s role is more often emphasized in the pathogenesis of metabolic diseases. Besides the saturation of fat storages in the body, the serum leptin level is also influenced by other factors, such as the female sexual hormones during the ovarian cycle. Our goal was to determine these hormonal fluctuations in the bitch and their influences on the blood leptin level. A further goal of our investigation was to determine whether an alternative percentage body fat measuring tool, which is based on impedance measuring, could be useful in clinical practice. 18 non-pregnant female Beagle ´s cycle diagnostics were made and after an overnight fasting period blood samples were taken every two weeks in a six week period. The progesterone, oestrogen, trigliceride, cholesterol and leptin levels were determined. The dogs were divided into two groups according to their body condition scores (BCS 3 and 4) and after a weight determination their body fat percentages were measured. The ovarian cycle and the leptin didn´t show any connections, despite of the only paper written about a similar topic as our own (Saleri et al., 2003), where they found correlation. We did not notice any significant changes in leptin or oestrogen values either. The leptin levels where significantly lower than what can be found in the literature (BCS 3 : 0.529 0.374, BCS 4: 1.660 1.178 ng/ml). This could have been due to more than 24h fasting and the cold temperature, since the samples were taken outdoors during winter. The results of the bioimpedance measuring tool showed strong correlations with the counted percentage body fat, but not with the leptin levels. Our measurements under farm conditions did not show enough accuracy. In overall, we determined that there is no connection whatsoever between the dog´s ovarian cycle and leptin level. The bioimpedance measuring tool´s values correlated well with the counted body fat percentage, but not with the leptin level. Further investigations are needed to assess the usefulness and accuracy of this device during clinical practice.