PubMed Health⌕ Search

Biomedical subjects

O Kratochvíl

Publications and source records attributed to O Kratochvíl.

18 recordsLinked to original sources
PubMed1983

Effects of exercise on serum cortisol and thyroid hormones.

Serum levels of hydrocortisone, T4, T3 and rT3 were estimated before and after exercise. In group A, untrained young subjects had to cope with a submaximal, fractionated load on a bicycle ergometer. T3 increased, rT3 and cortisol decreased, T4 remained unchanged. Sportsmen in group B accomplished a 10 or 15 km run as a part of their regular training. A rise of cortisol and rT3 was observed, T3 remained unchanged and T4 decreased. In better trained sportsmen the initial level of serum T3 exceeded the upper border of normal values (3.3 nmol/l) and the terminal values of cortisol reached a higher value than in the less trained subjects. It is suggested that the mobilization of fuel from energy stores and the oxidative processes are better regulated in trained sportsmen than in untrained subjects. A sign of the best adjustment to a long run was accompanied by an initial serum T3 above the normal borderline and by a great increase of cortisol after the run.

Adult↗
PubMed1981

Effects of total fasting in obese women. IV. Response of serum triiodothyronine (T3) and reverse triiodothyronine (rT3) to administered T3.

Serum levels of T4, T3, rT3, RT3U and TSH were estimated in 12 obese women in the course of a 14-day fasting. Seven of these patients were treated with T3 in a daily dose of 60--80 micrograms. Fasting led to a small increase of serum T4, while fasting combined with T3 administration was accompanied by a small decrease of serum T4. Serum T3 decreased in the course of the first 2 days of fasting to 40--50% of initial values and remained at this low level up to the 15th day of fasting. In the T3 treated group a prompt increase of serum T3 was recorded (+80%), followed by a steady decrease, reaching the control values on day 15, in spite of a continuous T3 administration. Serum rT3 in the untreated fasting group steadily increased up to the 12th day (+43%) and then dropped below the control value (-28%). In the treated group after a non-significant increase (+22%), a decrease of serum rT3 was also observed (-42%). Fasting was accompanied by a tendency to increased serum RT3U values, in the T3 treated group no change occurred. TSH in the untreated fasting women remained practically unchanged while T3 administration was accompanied by a tendency to a transient decrease. The heart rate showed a non-significant tendency to increase in the T3 treated group and the last week of fasting was also accompanied in several patients by a larger weight loss. These results suggest that in addition to an enhanced synthesis of rT3 to the detriment of a decreased production of T3 from T4, an increased catabolism of administered T3 and of endogenous rT3 is involved in a strict calorie restriction. An abortive T3-TRH-TSH feed-back may also operate in these conditions.

Adult↗
PubMed1980

Effects of diet, exercise and anorexigenic drugs on serum thyroid hormones.

The serum levels of T4, T3 and rT3 were estimated in moderately obese women treated with diet (900-1000 kcal) and 4 h of exercise, supplemented with placebo or anorexigenic drugs (phenmetrazine, phentermine and mazindol). After 12 days of treatment, no change in serum T4 occurred in the placebo group (-4%), while in the groups with anorexigenic drugs a significant rise of T4 was observed (phenmetrazine +33%, phentermine +14% and mazindol +20%). Serum T3 decreased significantly in the placebo and the anorexigenic groups to a similar extent (from -21% to -27%) with the exception of mazindol. We did not notice any decrease of T3 in this group (-3%). A rising trend of serum rT3 was observed in all 4 groups, with a statistical significance for mazindol only. It is suggested that 1) a combined energy deficit produced by diet and exercise leads to a pattern of serum thyroid hormones similar to that observed in resting patients on a total fast; 2) the rise of serum T4 after the administration of anorexigenic drugs is due to their sympathomimetic effects; 3) the largest weight decrease observed in the mazindol group (6.7 kg) may be due to the unchanged serum T3 level, while in the other groups a decrease of serum T3 was observed. The lowest weight loss was observed in the placebo group (4.9 kg) with a pronounced decrease of T3 (-24%).

Appetite Depressants↗
PubMed1978

In vitro and in vivo inhibitory effect of dehydroepiandrosterone on respiration.

The inhibitory effect of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEA-S) was tested either in vitro with the use of Clark electrode combined with polarography or in vivo using the Spirolyt apparatus. In vitro, DHEA and progesterone showed a marked inhibitory effect on oxygen consumption by the rat heart liver mitochondria. A decrease of oxygen consumption was also observed with electron transporting particles (ETP). However, in both instances DHEA-S was without effect. In vivo, DHEA inhibited whole body oxygen consumption in rats, provided the steroid was injected in a dose of 50 mg kg-1 and 1--16 h before the measurement. No effect was obtained 9 h after DHEA injected in a dose of 5 mg kg-1. Also DHEA administered per os (25 mg kg-1) for six days was without effect as measured 16 h after the last dose. These data are discussed in connection with the beneficial effect of DHEA-S administered to patients with angina pectoris.

Animals↗