​Study of the Relationship between the Levels of L-carnitine and NO Metabolites in Blood Plasma and Seminal Plasma in Stallions

Abstract

Background: Artificial insemination with chilled sperm is a reproductive biotechnology often used in horse breeding. However, maintaining the acceptable sperm quality after cooling, which affects the frequency of pregnancy, remains an urgent problem at the present time. Therefore, clarifying the role of important physiological metabolites, such as L-carnitine and nitric oxide, is a significant aspect in terms of possible improvement of the quality of cryopreserved sperm. Methods: The study included 35 breeding stallions, 27 of which were stallions of the Arabian breed and 8 were of the Soviet heavy draft breed. The content of total, free and bound carnitine and NO metabolites was determined by photometric method in the samples of seminal plasma and blood plasma. The correlation coefficient between the content of L-carnitine and the level of NO metabolites was also determined. Result: We have found a direct moderate correlation between the level of total and free L-carnitine in the seminal plasma and blood plasma. The study has also revealed a positive correlation between the level of all L-carnitine fractions and NO metabolites in seminal plasma. In addition, there was a positive correlation between the total L-carnitine of blood plasma and NO metabolites in seminal plasma.