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D Weinert

Publications and source records attributed to D Weinert.

48 records · Page 3Linked to original sources
PubMed1988

[Frequency and phase correlations of the biorhythms of metabolic indices in mice during their postnatal ontogeny].

In laboratory mice the daily rhythms of feeding, plasma insulin, blood glucose and liver glycogen were investigated beginning from an age of 1 week to 52 weeks. For all parameters circadian and ultradian rhythms changing in the course of development could be quantified. During juvenile phase and inversion of all patterns connected with temporary increasing ultradian components takes place. The beginning and the end of this inversion are specific for various parameters, to that changing frequency and phase correlations could be obtained. The lowest degree of phase correspondence is found at weaning, it reaches its maximum in adults and decreases again in older mice. The possible consequences of demonstrated phenomena for the stability of the functional system and the existence of sensitive phases during postnatal ontogeny are discussed.

Aging↗
PubMed1987

[Ontogenetic changes in the circadian rhythm of plasma insulin and its correlation to food intake].

In experiments with laboratory mice of different age (3, 9, 13, 18, 31 and 52 weeks old) directed changes of the daily pattern of plasma insulin concentration depending on the development stage of the animals could be quantified. The circadian acrophase undergoes a negative shift from the end of dark/beginning of light period in 3-weeks-old mice to the end of light/beginning of dark period in adults. The amplitude decreases up to an age of 9 weeks, whereas the amount of ultradian components is high, and increases during further development. Similar changes could be obtained for the daily pattern of feeding activity, occurring however some weeks earlier. The result is a temporary desynchronisation. In adult animals the phase correlations are relatively stable. The plasma insulin concentration reaches its maximal value before the maximum of feeding activity, thus stimulating a high food consumption and utilisation rate.

Aging↗
PubMed1986

Circadian rhythm of eicosanoid formation as affected by dietary linoleate.

Circadian rhythms of eicosanoid formation were investigated in linoleic acid (LA) rich (sunflower seed oil, 13.3 cal% LA) and LA deficient (hydrogenated palm kernel fat, 0.5 cal% LA) diet fed male Wistar rats adapted to an artificial lighting regimen of 12 hours light and 12 hours darkness. Over a period of 24 hours we examined at 4 hour intervals eicosanoid formation in the aorta (PGI2, PGE, PGF2 alpha), in the heart (6-keto-PGF1 alpha, PGE, PGF2 alpha, TXB2), in the kidney (PGE, PGF2 alpha) and in the brain (PGE, PGF2 alpha). Two types of circadian variation curves were observed: Low eicosanoid formation in the light period and increase in the dark cycle (PGE in aorta and heart, TXB2 in heart). The increase in eicosanoid formation in the dark cycle was diminished after an LA deficient diet. Continuous decrease (PGI2 in aorta) and increase (PGE in the brain), respectively, in the course of the day, without differences between the two dietary groups. We assume that the circadian oscillations of eicosanoid formation might be of importance for the development of the circadian time structure of the organism.

Animals↗
PubMed1986

[Desynchronization of the circadian rhythm of plasma insulin levels and feeding schedules after inversion of periodicity].

In experiments with laboratory mice a desynchronisation of daily rhythms in plasma insulin concentration and feeding after inversion of the light-dark periodicity is documented. Whereas the feeding rhythm follows the exogenous Zeitgeber (differences concern above all the quantity of food which decrease after inversion), the acrophase of the hormone rhythm is stable in relation to astronomic time. The daily mean, however, is reduced and the main maximum is split into three components. The results support the hypothesis that rhythms of the two investigated parameters are generated by separate oscillators.

Animals↗
PubMed1985

[Circadian rhythm of 3-methoxy-4-hydroxymandelic acid and 3-methoxy-4-hydroxyphenylacetic acid in the urine].

The excretion of the catecholamine-metabolites 3-methoxy-4-hydroxymandelic acid and 3-methoxy-4-hydroxy-phenylacetic acid shows circadian variation. In applying the cosinoranalysis, we tested the normal process of the variation over 3 d and found partly significant circadian rhythms of the excretions with the maxima occurring in the second part of the day to the evening hours and the minima occurring at night. By prescribing the course of the day (fixed time of food intake as well as of sleeping) effects of synchronisation could be found from d 1 to 3. The possible importance of these circadian oscillations for an early or differential diagnosis and the question of the reduction and optimization of the time necessary for collecting urine are discussed.

Adrenal Gland Neoplasms↗
PubMed1984

Chronobiologic and metabolic characterization of rats fed low or high linoleic acid diets.

The influence of a modified endogenous prostanoid synthesis on circadian rhythmicity at different functional levels (prostanoid formation, behavioural parameters, circulatory indices, hematological parameters, energy metabolism) was investigated. The daily rhythmic changes observed for all parameters were partly modified by the variation of dietary linoleate intake.

Animals↗
PubMedDate not supplied

[The analgesic efficacy of sulfur mud baths in treating rheumatic diseases of the soft tissues. A study using the double-blind control method].

Changes in pain thresholds assessed in 16 trigger points were traced in two randomly selected groups of patients subjected to diluted mud baths in the presence or absence of sulfur compounds. Sulfur baths produced a significant lowering of pain sensitivity. The effect was augmenting with the number of procedures, the rise slowing down to the end of the course.

Adolescent↗