ISSN:0022-1945    

DOI:10.1080/09291018909359992

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The locomotor activity of individualMusca domesticaflies was recorded photoelectrically. The pattern consisted of unimodal circadian rhythms in 29% of the cases, of more than one circadian rhythm visible in the same actogram ("compound rhythms") in 63% and was arrhythmic in 8% of the cases. When 1 mM LiC1 was added to the drinking water, only5%of the flies which exhibited an unimodal rhythm before were still showing this pattern. 57% snowed a compound rhythm and 38% became arrhythmic under LiCl. Flies with compound rhythms continued to show this pattern (73%), or became arrhythmic (27%). Arrhythmic flies stayed arrhythmic under Li+treatment. Thus Li+decreases the percentage of rhythmic and increases the percentage of arrhythmic flies. This finding is discussed in respect to reduced mutual coupling of circadian pacemakers and complete asynchrony among the individual oscillators after Li+application.

ISSN:0022-1945    

DOI:10.1080/09291018909359993

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Stationary cultures ofEuglenawere investigated in LD 12:12, LD 0.25:1.75, and in LL, at a temperature of 23 °C. In these conditions, protein synthesis, cell shape and/or phototaxis exhibited circadian rhythmicity, whereas tyrosine aminotransferase activity showed a circa‐4‐h periodicity. Simultaneous measurements of cell shape and tyrosine aminotransferase, carried out in LL, at either 27.5 or 18 °C, demonstrated concomitance of circadian and ultradian rhythms in the same cell cultures.

ISSN:0022-1945    

DOI:10.1080/09291018909359994

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The trophic influence of gastrin on cellular proliferation in rodent gut has been described. Proglumide, a specific competitive inhibitor of gastrin, can exert an antitrophic effect and can block pentagastrin‐stimulated DNA synthesis. We performed this study in order to determine whether the circadian system influenced the interaction of endogenous gastrin and exogenous proglumide on DNA synthesis in several organs in 154 CD2F1mice. The mice had been acclimated to a light‐dark cycle on 12:12 before the study was begun. One‐half of the mice received intraperitoneal injections of proglumide every 8 h for 2 days (6 doses, 250 mg/kg): controls received saline injections. Beginning 8 h after the last dose, mice were killed by cervical dislocation every 3 h for 30 h. Incorporation of tritiated thymidine (DNA synthesis) was measured in the esophagus, the glandular and nonglandular stomach, spleen, and proximal and distal colon. In every organ, significant circadian rhythms were found (p < 0.01). Cosinor analysis for each organ described no significant differences in mesor, amplitude, or acrophase between the two groups, except in the glandular stomach. When circadian rhythmicity was considered, proglumide did not appear to alter DNA synthesis in the mouse gut, except to increase the overall activity in the glandular stomach. This finding differs with published reports that proglumide is antitrophic.

ISSN:0022-1945    

DOI:10.1080/09291018909359995

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Urinary excretory rhythms were studied in male and female rats during a LD cycle (12:12), under constant light (LL) conditions and in blind rats (DD). During DD the period was about 24.5 h. During LL the period was longer or shorter (the latter only in male rats) than 24 h. However, after about 8 days of LL the period again changed, although the rhythms remained free‐running. There were significant shifts in the acrophases during the free‐ running phase: the direction and magnitude depended on the illumination conditions, the duration of LL and the sex of the animal. The difference in internal phase angles between sodium and potassium increased in female rats during the free‐running phase, but decreased in male rats. The rhythms were less precise in female rats than in male rats, but the periods were similar. These results therefore indicate a difference in the organization of the circadian system between female and male rats.

ISSN:0022-1945    

DOI:10.1080/09291018909359996

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The circadian rhythms of three peptide hydrolases and of maltase were studied in homogenates of rat intestine and in fractions of brush border membrane. Changes in the protein ratio between the brush border membrane (BBM) fraction and the crude homogenate are responsible for the overall rhythm. Differences in amplitude and acrophase for the different enzymes, however, indicate a difference in stability of these hydrolases.

ISSN:0022-1945    

DOI:10.1080/09291018909359997

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

It was hypothesized that the daily intake of a geriatric preparation containing vitamins, minerals, trace elements and ginseng, would strengthen the sleep‐wake rhythm and thus have a positive influence upon characteristics of sleep. A total of 32 subjects (age 61 ‐92, mean 78 yr, 23 females) was recruited from a local elderly home. In a double‐blind procedure 16 subjects received the geriatric preparation for a period of 10 weeks, while the other 16 subjects received a placebo. Before treatment, a 48‐hour polygraphic home‐recording was made of the EEG, and ‐ during sleep ‐ of the chin EMG, the EOG and respiration. At the end of the treatment period ( 10 weeks later) this recording was repeated. After exclusion of low‐quality recordings, the data of two groups of 10 subjects each were analyzed. The results show a significantly increased percentage of REM sleep for the experimental group after treatment, and a similar trend for Slow Wave Sleep. Moreover, inspection of the spectra of the 24‐hour EEG recordings suggests an increased circadian amplitude of the low‐frequency EEG.

ISSN:0022-1945    

DOI:10.1080/09291018909359998

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The circadian rhythm of human rectal temperature was compared in three female subjects living for 14 days under almost natural conditions without uses of electrical lamp during summer and winter. The time of morning rise of the rectal temperature rhythm was earlier in winter than in summer. Cosinor analysis revealed that the acrophase was earlier in winter in two subjects and the amplitude was also larger in winter in all three subjects. The findings are discussed in terms of circadian physiology.

ISSN:0022-1945    

DOI:10.1080/09291018909359999

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The triterpenoid azadirachtin was injected in adult house flies and the effect on the circadian rhythm of locomotor activity studied. In most cases (83%) period was increased (by 0.4 h, as a mean), whereas flies injected with the solvent of azadirachtin, ethanol, increased period in 22% only (by 0.3 h, as a mean). In 46% of the azadirachtin injected flies a splitting of the activity rhythm into two components with the same period length was induced, whereas only one of the ethanol controls (2%) showed splitting after injection. LiCl added to the drinking water changed the activity pattern from splitting to arrhythmicity in about 50% of the azadirachtin treated flies.

ISSN:0022-1945    

DOI:10.1080/09291018909360000

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0022-1945    

DOI:10.1080/09291018909359991

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor