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Biomedical subjects

H Krzywanek

Publications and source records attributed to H Krzywanek.

At least 19 recordsLinked to original sources
PubMed2002

Effects of aqua-treadmill exercise on selected blood parameters and on heart-rate variability of horses.

The objectives of the present study were to investigate the effects of Aquatraining of horses (aqua-treadmill exercise; treadmill manufactured by Equitech - L.u.S. Equipment, Warendorf, Germany) on selected blood parameters [lactic acid concentration (mmol/l), haemoglobin content (g/l)] and on heart-rate variability (HRV) [heart rate (beats per min; b.p.m.), standard deviation of all NN-intervals (SDNN; ms), normalized power of the low and high frequency band (LFnorm, Hfnorm; au), % recurrence, % determinism and ratio(corr)]. Seven horses performed six exercise tests with different work loads (walking (x = 1.56 +/- 0.08 m/s) and trotting (x = 2.9 +/- 0.13 m/s): dry, water above the carpus and water above the elbow). The standardized test-protocol was: 5 min warm-up at walk while the water was pumped in, followed by the 20-min exercise period at walk or trot, followed by a 5-min walk while pumping out the water. Blood samples were taken prior to each test at rest in the stable, as well as exactly 5 min after the end of the 20-min exercise period. Electrocardiograms were recorded during rest and the 20-min exercise period. Compared to rest, neither the chosen velocities, the two water levels, nor the dry tests led to a significant increase of the lactic acid concentration in any horse. The haemoglobin content showed a significant increase as a result of exercise. Significant differences could be found between the heart rates at rest and the six exercise tests and between the mean of the levels 'walking' and the mean of the levels 'trotting'. An exercise-induced change of HRV was characterized by a decreasing SDNN, a significantly higher LFnorm (sympathetic influence) combined with a significantly lower HF(norm) power (parasympathetic activity) and a rising degree of order (significantly higher % determinism and nearly unchanged % recurrence) and stability (significantly rising ratio(corr)) of the recurrence plot. In conclusion, the used training-protocol for aqua-treadmill exercises only represents a medium-sized aerobic work load for horses, but the different levels of burden were indicated especially by changes in HRV.

Animals↗
PubMed1999

Monitoring training success using a lactate-speed relationship.

Monitoring training by measuring blood lactate content is a well-known procedure in sports physiology. Because of the difficulties in standardizing a test procedure in field studies, this method is fraught with considerable problems when applying it to race horses. The aim of the present study was to develop a test procedure which is able to give evidence about the training state of different race horses after nonidentical test-loads. Under almost identical environmental conditions, the level of blood lactate was determined in five trotters which were kept in training. Immediately after the single phases of a three-stage test procedure (handicap: 'small', 'medium' and 'high' load for the animals chosen at the discretion of the coach) blood samples were drawn. The lactate value was set in relation to the speed of each animal. A curve of the equation y = y0 + e(k + b*x) was fitted with r2 > 0.93 to these data. With the aid of this equation, the 'comparative speed', V, was calculated; this is the arithmetic mean of the velocities V4, V8 and V20, obtained by inserting the appropriate values for (imaginary) lactic acid concentrations in the formula. With the aid of V it was possible to detect both an increase and a decrease in physical fitness. In this way, animals tested together on one date, as well as the development of one animal tested on several dates, can be scored. Advantages and limitations of the method are discussed in detail.

Animals↗
PubMed1998

Selected blood parameters during recovery from strenuous running exertion in trotters.

During training, in 10 trotters, blood samples from the vena jugularis were taken before and after a heat with 80% of maximum capability as well as in the recovery period. Lactic acid concentration and pH-value, haematocrit and haemoglobin content, as well as protein concentration and osmolality were measured. With the exception of protein concentration, the time course of the values during the recovery could be described by simple mathematical models (biexponential or exponential equations). Only in the case of blood lactate concentration, the basal value was not yet achieved 120 min after the end of exercise. In the case of the other examined parameters, the homeostasis was restored earlier. Therefore, it seems to be recommendable when performing tests with preliminary heats and finals on the same day to stick to a break of at least 2 h between two races.

Animals↗
PubMed1996

[Changes of serum enzymes, lactate and hemoglobin concentrations in the blood of young trotting horses due to training exertion].

Until the age of about 2 years, trotters normally grow up on pasture without any kind of training. In the stud farm Lindenhof (Templin, Germany), however, these first 2 years are used for a special fitness training for the young animals: 2-3 times a week, a group of the yearlings is forced to run a distance of about 1700 m on a track at an average speed of up to 10 m/s. Until now, little was known about changes of blood parameters which may occur during such special exercise. This study therefore investigated the activity of selected serum enzymes (aspartate-amino-transferase (AST), alanine-amino-transferase (ALT), gamma-glutamyl-transferase (gamma-GT), lactic dehydrogenase (LDH), alkaline phosphatase (AP), creatine kinase (CK)) and the variations of hematocrit, hemoglobin, lactate, protein, and urea concentration before and after exercise. Except for activity of AP and CK and concentration of urea, all parameters showed a distinct increase after exercise. In particular, the rise in lactic-acid concentration with values up to 23.08 mmol/l was remarkable, however, none of the parameters reached a pathological level. It is therefore concluded that exercise for young trotters over a medium distance-even at high speed-does not cause any injury of myocardium, skeletal muscles or liver cells.

Animals↗
PubMed1995

Endogenous oscillator and regulatory mechanisms of body temperature in sheep.

To determine the influence of various feeding schedules (different times of feeding, times without feeding) on the time course of heart rate (HR), electric activity of cervical muscles (EMG), motor activity (ACT) and body temperature (TB) in ruminants, 5 sheep were equipped with portable dataloggers able to register and store these variables every 30s. Under controlled housing conditions, the temporal changes which occur were registered for 12 consecutive days each period at least. During experimental periods with various feeding times HR and TB were within the physiological range and all variables showed pronounced peaks which were associated with the time of food presentation. On days without feeding TB (38.8 degrees C) was at the lower limit of this range and HR (56 bpm) was extremely below this limit; similar peaks as before were not detectable. The circadian rhythms of HR and TB seemed not to be influenced by the different times of feeding, but there were hints, that photic or social factors could act as a zeitgeber for ACT. Remarkable was the fact that the downregulation of the food induced rises of HR and TB was determined by the phase angle of the circadian rhythm.

Animals↗
PubMed1992

[Evaluation of the postoperative "state of health" using the example of the body core temperature rhythms of sheep].

A postoperative (p.op.) estimation of "healthiness"--especially an estimation of duration of possible existing changes, caused by surgical treatment--is important not only for the ongoing of the healing up process. A re-activation of treated farm or laboratory animals which is set up too early might produce reduction of efficiency or falsification of experimental results. Investigations on p.op. de-synchronisation have proved that "healthiness" means--besides the absence of clinical symptoms--also stable relations among the circadian rhythms. As the ultradian rhythms (wavelength less than 24 h) which exist beside the circadian ones depend on endogenic and exogenic factors much more than the circadian rhythms do, the aim of this study was to investigate strength and especially duration of changes p.op. in using core temperature rhythms of sheep as example, by setting great value on investigating ultradian rhythms. The core temperatures of 5 Merino-mixed sheep were permanently measured for 4 weeks p.op. by special radiotelemetric equipment, under controlled circumstances. All recorded data have been expertised "macroscopically" and Fourier-analysis was employed for judging phase shift and intensity of existing rhythms. Though no signs for systemic disturbances could be found and the recorded temperature always was in between the physiological range, important shifts of phases and variations in intensities in the ultradian scope as well as in the circadian one occurred. The "normal" or final phase relations and the constant daily pattern of intensities in sheep were reached 16 days p.op. earliest.

Animals↗
PubMed1990

Variations of core-temperature rhythms in unrestrained sheep.

Variations of core-temperature rhythms occurring during a "normal" day (24-hour period without extraordinary challenges for organism) were studied in 5 male sheep. To record the influence of the metabolic processes in different organic systems, core temperatures were measured at various locations at the same time. To minimise any influences due to measurement or behavior (e.g., effects of isolation), a telemetric system was used for registration and animals were kept without restraint in their habitual herd. Particularly biphasic circadian rhythms were found, and feeding schedule as zeitgeber is discussed. Beyond that, independent from point of measurement short-time rhythms with wavelengths of 140 and 90 min were found. Therefore, an origin in the central nervous system can be supposed. Rhythms with wavelengths of 3 hours, 75 min and 1 hour were not stable throughout a whole 24-hour period and did not occur at all measurement points in the same intensity. A comparison of anatomical placements of the various measurement points leads to the realization of distinct organic functions as sources for these rhythms.

Animals↗
PubMed1976

Acid-base values of standardbred horses recovering from strenuous exercise.

Blood gases, lactic acid concentrations, and pH were measured in arterial and mixed venous blood in moderately conditioned Standardbred horses after a standardized exercise load of 1.6 km in 2 minutes, 40 seconds. Samples were obtained at rest, immediately after exercise, and at 3, 6, 15, 30, and 60 minutes after exercise. Arterial oxygen tension and mixed venous oxygen tension increased after exercise, reaching peak values at 6 minutes. Arterial oxygen tension returned to the resting (preexercise) value by 15 minutes, and mixed venous oxygen tension by 30 minutes. Arterial carbon dioxide tension decreased immediately after exercise, reaching its lowest value at 6 minutes, and returned to resting value by 30 minutes. Mixed venous carbon dioxide tension reached its highest value immediately after exercise, then decreased to less than the resting value, reaching its lowest value by 15 minutes, and returned to normal by 60 minutes. Lactic acid concentration increased immediately after exercise, reaching its highest value at 6 minutes, and returned toward normal by 60 minutes. Arterial pH decreased immediately after exercise, reaching its lowest value at 6 minutes, and returned to normal by 60 minutes. Mixed venous pH reached its lowest value immediately after exercise, then began to increase, and returned to normal by 60 minutes. The decrease in mixed venous pH was more pronounced than that in arterial blood since, in addition to the increase in lartic acid, there was a considerable increase in mixed venous carbon dioxide tension.

Acid-Base Equilibrium↗