Immunology of Physical Exercise: Is Equus caballus an Appropriate Animal Model for Human Athletes?

Domestic horses routinely participate in vigorous and various athletic activities. This enables the horse to serve as a model for studying athletic physiology and immunology in other species, including humans. For instance, as a model of physical efforts, such as endurance rides (long-distance running/aerobic exercise) and races (anaerobic exercise), the horse can be useful in evaluating post-exercise response. Currently, there has been significant interest in finding biomarkers, which characterize the advancement of training and adaptation to physical exercise in the horse. The parallels in cellular responses to physical exercises, such as changes in receptor expression and blood cell activity, improve our understanding of the mechanisms involved in the body's response to intense physical activity. This study focuses on the changes in levels of the pro- and anti-inflammatory cytokines and cellular response in the context of post-exercise immune response. Both the direction of changes in cytokine levels and cellular responses of the body, such as proliferation and expression of surface markers on lymphocytes, monocytes and neutrophils, show cross-functional similarities. This review reveals that horses are robust research models for studying the immune response to physical exercise in human athletes.

Exercise-related changes in the anabolic index (testosterone to cortisol ratio) and serum amyloid A concentration in endurance and racehorses at different fitness levels.

Increased training loads in both human and equine athletes are generally implemented to improve their physical performance. These loads are tolerated only within appropriate training periodization with regard to recovery time. Otherwise, training overload causes failure in the systemic adaptation, which at first leads to overreaching, and progressively to overtraining syndrome (OTS). Exercise endocrinology, and anabolic/catabolic balance as an indicator of athlete performance status and OTS has continued to attract attention. In human medicine, changes in testosterone and cortisol levels, as well as the testosterone to cortisol ratio (T/C; anabolic index), are suggested to be sensitive stress markers. However, there is a lack of research investigating these parameters for use in equine sports medicine. The aim of the study was to investigate the differences in testosterone, cortisol, and T/C in response to a single training session in two types of equine sports: endurance and race, together with serum amyloid A (SAA), the main acute phase response indicator of physical effort, and the overall health status in horses. Two groups of horses were enrolled in the study: endurance (n = 12) and racehorses (n = 32) of different fitness level. Blood samples were obtained before and after the exercise. On average, T increased 2.5 times after the race training in experienced racehorses and dropped in endurance horses regardless the fitness level (p < 0.05). In endurance horses, a decrease in T/C occurred after training in inexperienced horses (p < 0.05). In racehorses, a T/C decrease occurred in the inexperienced group (p < 0.05) and an increase in the experienced (p < 0.01). In conclusion, T/C ratio was found to be a potentially reliable indicator of fitness status especially in racing horses. These findings provide insight into the physiological response of the horses to different types of exercise and the potential use of hormone levels as markers of performance and adaptation.

C-Reactive Protein as a Diagnostic Marker in Dogs: A Review.

Acute phase response is a nonspecific reaction to disturbances in homeostasis during which the production of some Acute Phase Proteins (APPs) is stimulated; they are sensitive but nonspecific markers of systemic inflammatory processes. The major positive APP in dogs is the C-reactive protein (CRP). The dynamic of its concentration changes fast, rising and decreasing rapidly with the onset and removal of the inflammatory stimulus. It increases within the first 4-24 h after the stimulus and reaches up to a 50-100-fold increase of the baseline level. It has been documented that this APP's concentration is elevated during several diseases, such as pyometra, panniculitis, acute pancreatitis, polyarthritis, sepsis, immune-mediated hemolytic anemia, and neoplasia in dogs. In clinical practice, canine CRP is mostly measured to detect and monitor systemic inflammatory activity and the efficacy of treatments, because it is a more sensitive marker than shifts in leukocyte counts. Blood serum CRP concentration is becoming a part of routine biochemistry panels in many countries. In this article, changes in CRP concentration and its clinical application in healthy and diseased dogs are discussed.

The many problems of somatic cell nuclear transfer in reproductive cloning of mammals.

In 1996, when Dolly the sheep was born, a new, utopian era was expected to begin. Science fiction and popular culture instantly threatened the public with shortly upcoming human clones, portraying it as a very easy and instant procedure. Practice has proven otherwise; it exposed how little is known about the early development of mammals and epigenetic reprogramming. Unfortunately, somatic cell nuclear transfer success rate in mammals has not changed much since its very beginning. It is not uncommon that hundreds of oocytes need to be reconstructed to obtain a single live birth. In this review we provide a brief summary of the progress and problems of the field; beginning with selection of the donor cells and their susceptibility to different methods of epigenetic reprogramming; methods of the later gene activation, placental abnormalities, and their possible causes; to health issues that such offspring is prone to.