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Biomedical subjects

L Lyhs

Publications and source records attributed to L Lyhs.

At least 37 records · Page 2Linked to original sources

[Effect of noise on the physiological functions in fowl. 2. Adaptation to noise of white leghorns and broilers].

Two experimental groups and series were compared (leghorns and broilers as well as two age groups of broilers) for their adaptive responses to repeated noise application. The noise was 100 dB and applied daily 30 minutes. The reference for comparison was the plasma-11-hydroxycorticosteroid concentration (11-OHKS). The results differed somewhat from those obtained earlier from one first short-time noise application, in that the rise in plasma glucocorticosteroid concentrations dropped from 431 to 210 per cent of the initial values in adult leghorns exposed to repeated noise stress over seven days. Adult broilers, however, did not exhibit any difference in the magnitude of rise of 11-OHKS concentrations by comparison between first and seven days of repeated stress. The initial values, however, were reached earlier by repeated noise application.

11-Hydroxycorticosteroids↗

[Effect of noise on the physiological functions in fowl. 3. Effects of primary and repetitive acoustic stimulation on glucose and free-fatty-acid plasma levels in broilers of different age groups].

The effects of first and repetitive noise applications to broilers, aged 14, 28, and 56 days, were tested by the responses of the energetic substrates plasma glucose concentration and free fatty acids. The plasma concentrations of glucose and free fatty acids in broilers at slaughter age with no exposure to noise were higher than those in younger animals. Regular daily noise application of 100 dB, 60 to 8,000 Hz, for 30 minutes, which began on the first day of age, led to rises in the plasma glucose levels of animals aged 56 and 28 days even prior to renewed acoustic stimulation, which obviously was a conditioned reflex. Such rises were accompanied by decline in plasma concentrations of free fatty acids, which phenomenon was attributed to higher initial values of plasma glucose. First as well as repetitive noise application led to changes in the plasma content of energetic substrates. Both the direction and magnitude of the reaction appeared to depend on the given initial value. The plasma level responses of glucose and free fatty acids were opposite to one another in all animals, 56 days of age, which were exposed to repeated noise.

Acoustic Stimulation↗

[Effect of long-lasting noise on the plasma concentration of catecholamines, glucocorticosteroids and PBI in pigs].

Exposure of pigs with a body mass of 25-30 kg to long-lasting motor noise (108 dB, 60-8000 Hz, 72 hours) results in a considerable increase of catecholamine concentration in the plasma. Coincidently there is a sharp continuous decrease of the 11-OHKS in the plasma during the whole period of exposure to noise. Immediately after stopping the acoustic irritation the concentration of plasma corticosteroids increases again. The electroencephalogram (EEG) giving evidence of inhibition signs during exposure to noise an adaptation effect of the information processing system is concluded. The increase of the PBJ during the period of acoustic stress points to an increased function of the thyroid gland but simultaneously it is considered to be an expression of the elevated adrenergic situation. By reason of the strong deviation of the three observed regulatory systems must be concluded that longer-lasting exposure to noise with the applied quality and intensity represents a stress situation for pigs having noise character as established for men. A possible influence on the productivity of the pork type pig by permanent acoustic stress is indicated.

11-Hydroxycorticosteroids↗

[The course of plasma concentrations of cathecholamines and corticosteroids and of plasma--bound iodine (PBJ) in swine under the effect of noise and of various methods of raising].

Plasma concentrations of 11-OHKS were transitorily increased with significance in pigs, 25 kg to 45 kg in live weight, exposed to short-time engine noise (120 dB, 60 to 8,000 Hz, 60 minutes). Intensity of noise application and duration did not cause significant variation of plasma concentrations in catecholamines nor in P.B.J. The catecholamines were on a rising trend. Those results supported the conclusion that both quality and quantity of applied noise are perceived by store pigs as factors of disturbance. Their noise nature is comparable to that perceived by man and laboratory animals. Decline in 11-OHKS after 55 minutes of exposure to noise was recorded also by other authors who had exposed other species to long-time noise. It seems to reflect adaptation mechanisms in the information-processing system. The reactivity to noise of the adrenal cortext of swine was found to depend on the form of keeping. Animals kept in groups responded to noise in the same way in which they would respond to acute cold, by significantly increasing rise of plasma concentrations of 11-OHKS. The above results were taken to support the conclusion that organic response to a specific stimulus depended on the level of each control circuit at the time of stimulation.

Adrenal Cortex Hormones↗

[Effect of anemia on various reactions of the domestic swine due to physical exertion. I. Initial values and characteristics of anemia].

In six anaemic and six healthy pigs at rest the following values were determined:--rectal temperature, heart rate, respiratory rate, haemoglobin (Hb), haematocrit (Hk), total haemoglobin (THb), plasma volume, blood volume, plasma osmolarity, lactic acid and glucose content of plasma, blood pH, carbon dioxide tension and base excess. There were significant differences between anaemic and normal pigs in Hb, THb, relative THb, Hk, mean cell haemoglobin concentration, lactic acid content; in the ECG there were differences in QT and ST intervals and the ratio of diastole to systole.

Anemia↗

[Effect of anemia on various reactions of the domestic swine due to physical exertion. 2. Components of cardiovascular function and body temperature].

The following measurements were made in six anaemic and six healthy pigs during and after physical exertion on a belt moving at 70 m/min for 10 minutes at environmental temperature of 22-24 degrees C and relative humidity of 55-65%:--rectal temperature (RT), heart rate, total haemoglobin, plasma volume (PV), blood volume (BV) and plasma osmolarity (PO). The increase: in RT and PO, heart rate during exercise, respiratory rate after exercise, and the fall in PV and BV during exercise as well as changes in erythrocytes were all more pronounced in anaemic pigs than in healthy pigs.

Anemia↗

[Effect of anemia on various reactions of the domestic swine due to physical exertion. 3. Changes in plasma glucose and lactic acid concentrations].

Six anaemic and six healthy pigs were exercised for ten minutes on a belt moving at 78 m/min. Initial blood glucose values in healthy pigs averaged 71.2 mg/100 ml, and they changed very little during and after exercise. Initial values were similar in anaemic pigs (70.7 mg/100 ml), but they increased continuously, during exercise, reaching a peak of 157.4 mg/100 ml one minute after the end of exercise. Blood lactic acid increased from 1152 to 2463 mmol/litre in healthy pigs during the first minute of exercise, and then fell gradually. In anaemic pigs it increased from 1652 to 8478 mmol/l during the ten minutes of exercise, and then fell gradually. Correlations between lactic acid and haemoglobin content, between rectal temperature and Hb, and between lactic acid and changes in rectal temperature were discussed.

Anemia↗

[Effect of anemia on various reactions of domestic swine due to physical exertion. 4. Changes of serum acid-base equilibrium].

Carbon dioxide tension, pH and the excess of base were determined in blood samples obtained from the posterior vena cava of six healthy and six anaemic pigs subjected to ten minutes of exercise on a belt moving at 78 m/min at 22-24 degrees C and relative humidity of 55-65%. The fall in these values during physical exertion was greater in anaemic than in healthy pigs. The roles of buffering capacity and rise in body temperature, and the relationship between blood lactic acid and base excess were discussed.

Acid-Base Equilibrium↗

[Evaluation of blood glucose concentration during exertion. 6. Effect of anemia on the glucose regulation capacity of domestic swine in standardized running exercise].

Individual mean blood glucose values and the scatter of individual values were determined in six healthy and six anaemic pigs before, during and after ten minutes of exercise on a belt moving at 78 m/min (environmental temperature 22-24 degrees C, relative humidity 55-65%). The glucose regulatory capacity of anaemic pigs was inferior to that of healthy pigs. Blood glucose regulation was related to haemoglobin content and to the increase in rectal temperature during exercise.

Anemia↗

[Lactic acid content of blood plasma in domestic swine of various breeds during physical exertion].

Lactic acid was determined by an enzymic method in plasma samples taken from 20 pigs of the German Edelschwein, German Landrace, German Saddleback and Edelschwein/Landrace crosses before, during and after being made to run on a band moving at 1.3 metres/second for ten minutes, at 10 degrees C and relative humidity of 65-75%. A special method was used to assess the degree of exertion. The lactic acid curve showed that Edelschwein and German Saddlebacks had a low regulatory capacity while German Landrace and the crossbred pigs had a large capacity. For assessing differences attributable to individuals or to breeds, the occurrence of the maximum lactic acid concentration during or after exercise was of special significance.

Animals↗

[ Glucose concentration in blood during exertion. 5. Use of the total distribution of blood glucose values during physical exercise or the estimation of response to exertion in various breeds of swine].

Blood glucose was determined by an enzymic method in 56 pigs of the German Edelschwein, German Landrace, German Saddleback breeds and Edelschwein/Landrace crosses before, during and after exercise on a belt moving at 1.3 metres/second for ten minutes, at 10 degrees C (winter) or 22-34 degrees C (summer) and relative humidity of 65-75%. Total plasma glucose was calculated from the plasma volume. Total scatter of values for blood glucose concentration and total plasma glucose was greater in Edelschwein and Saddlebacks than in Landrace and the crossbred pigs. There was a close and significant relationship between individual regulatory capacity and breed. The total scatter of blood glucose values was greater in winter than in summer.

Animals↗

[Effect of the type of management and training on heart rate, rectal temperature and respiration rate of domestic swine during physical exertion].

29 pigs (meat type of German Landrace) were kept in groups in a confined space (0.48 m2 a head; group E), in a normal area (1.2 m2 a head; group N) or in a normal area plus daily exercise (group L). After having been kept under these conditions for specified periods, the pigs were made to run on a band moving at 1.1 metres a second for 2 km. During exercise the heart rate increased to 275 beats a minute in group E and only 180 in group L. In group L the recovery pulse rate was greater and the absolute and relative heart weight smaller than in group L; rectal temperature after exercise was also higher than in group L. Values for group N lay between those of groups E and L. The relationship of respiration rate to rectal temperature after exercise was greater in group L than in groups E and N. Physical fitness of groups E and N was inferior to that of group L.

Animal Husbandry↗

[Hyperthermia in the rabbit. I. Studies on influencing circulation with exogenic hyperthermia].

Increasing the environmental temperature to 35 degrees C produced hyperthermia in 11 female rabbits, 80-90 days old. At the onset of hyperthermia the heart rate increased, but there was no further change after about two hours (range 1-3 hours); it remained constant at an increased rate until the end of the experiment. Blood pressure fell at first, but it had increased again after 90 minutes, and underwent no further change during the experiment. The mechanism of these circulatory changes were discussed in relation to the neutral control of body temperature regulation.

Animals↗

[Evaluation of the ability to regulate blood volume under standardized motoric stress].

Sixteen German Landrace pigs of the meat type were kept in individual cages (0.47 m2 floor area each) or in two pens of four pigs providing 1.05 m2 per animal, under otherwise identical conditions for 45 days, commending at a body weight of 45 kg. Plasma volume and plasma glucose were determined before, during and after the pigs made to run on a band moving at 1 m/s for 20 minutes at 24 degrees C. Changes in plasma volume were studied from the total scatter of values (total area covered by the curve of values). This made it possible to quantify individual regulatory capacity and the influence of management. Close confinement in an individual cage reduced the regulatory capacity of the plasma volume by 3.5 to 4 times. There were significant qualitative and quantitative relationships between intravascular fluid volume and intravascular glucose or glucose concentration.

Animals↗

[Hormone concentrations in the plasma of pigs kept under various husbandry methods].

A comparison of pigs weighing 30-50 kg reared either in groups or in individual cages showed that the management system affected the concentrations of catecholamines, 11-hydroxy corticosteroids and protein-bound iodine. Pigs kept in individual cages showed high concentrations of catecholamines and iodine, and low concentrations of corticosteroids. Pigs kept in groups showed high corticosteroids and low catecholamines and protein-bound iodine. The values for hormone concentrations in caged pigs were similar to those reported for the Poland China breed, which are not very resistant to stress produced by temperature and restraint.

11-Hydroxycorticosteroids↗

[Hyperthermia in the rabbit. II. Studies on influencing respiration with exogenic hyperthermia].

Rectal temperature, respiratory rate, arterial and venous pH and arterial and venous pCO2 were recorded at intervals of 15-30 minutes in female broiler rabbits exposed an environmental temperature of 35 degrees C, until they died. Respiratory rate and blood pH rose, and pCO2 fell, until a rectal temperature of 42 degrees C was reached. Upon further increase in rectal temperature the respiratory rate and pH began to fall, while pCO2 began to rise. The rabbits died when rectal temperature reached 43 degrees C. Features of respiratory function peculiar to the rabbit were discussed.

Animals↗