Diurnal Rhythm In Body Temperature Research Articles

A Wireless Pressure Sensor for ContinuousMonitoring of Intraocular Pressure in Conscious Animals.

An important aspect of eye health in humans and animal models of human diseases is intraocular pressure (IOP). IOP is typically measured by hand with a tonometer, so data are sparse and sporadic and round-the-clock variations are not well characterized. Here we present a novel system for continuous wireless IOP and temperature measurement in small animals. The system consists of a cannula implanted in the anterior chamber of the eye connected to pressure sensing electronics that can be worn by rats or implanted in larger mammals. The system can record IOP with 0.3mmHg accuracy and negligible drift at a rate of 0.25Hz for 1-2months on a regulated battery or indefinitely at rates up to 250Hz via RF energy harvesting. Chronic recordings from conscious rats showed that IOP follows a diurnal rhythm, averaging 16.5mmHg during the day and 21.7mmHg at night, and that the IOP rhythm lags a diurnal rhythm in body temperature by 2.1h. IOP and body temperature fluctuations were positively correlated from moment-to-moment as well. This technology allows researchers to monitor for the first time the precise IOP history of rat eyes, a popular model for glaucoma studies.

Environmental light and suprachiasmatic nucleus interact in the regulation of body temperature

The mammalian biological clock, located in the suprachiasmatic nucleus (SCN), is crucial for circadian rhythms in physiology and behavior. However, equivocal findings have been reported on its role in the circadian regulation of body temperature. The goal of the present studies was to investigate the interaction between the SCN and environmental light in the regulation of body temperature. All recordings were performed by telemetry in free moving male Wistar rats. Firstly, we demonstrated an endogenous circadian rhythm in body temperature independent of locomotor activity. This rhythm was abolished by stereotactic lesioning of the SCN. Secondly, we demonstrated a circadian phase-dependent suppressive effect of light (‘negative masking’) on body temperature. Light suppressed body temperature more at the end of the subjective night (circadian time [CT] 22) than in the middle (CT 6) and at the end (CT 10) of the subjective day. This circadian-phase dependent suppression was not demonstrated in SCN-lesioned animals. Surprisingly, after half a year of recovery from lesioning of the SCN, light regained its suppressing action on body temperature, resulting in a daily body temperature rhythm only under light–dark conditions. In contrast to body temperature, light could not substantially mimic a daytime inhibitory SCN-output in the regulation of heart rate and locomotor activity. The present results suggest that, after lesioning of the SCN as main relay station for the immediate body temperature-inhibition by light, secondary relay nuclei can fully take over this function of the SCN. These findings provide a possible explanation for the controversy in literature over the question whether the SCN is required for the diurnal rhythm in body temperature. Furthermore, they show that light may have an acute effect on behavior and physiology of the organism via the SCN, which extends beyond the generally acknowledged effect on melatonin secretion.

Spontaneous activity, sleep, and body temperature in rats lacking the CCK-A receptor

Because of a genetic mutation, the Otsuka–Long–Evans–Tokushima Fatty (OLETF) rat, a model for human non-insulin-dependent diabetes mellitus (NIDDM), shows no expression of the CCK-A receptor gene. We investigated the spontaneous physical activity, sleep, and body temperature in young OLETF rats that had not yet developed diabetes mellitus, and compared these data with age-matched control LETO (non-diabetic strain, Long–Evans–Tokushima–Otsuka) rats. The amount of large movements during the dark phase for the OLETF rats was significantly less than that of control rats. Thus, the amounts of total daily large movement and the ratio of dark-to-light phase movement in the OLETF rats were less than those of control rats, although the amount of small movement was similar for both groups. The diurnal rhythm of body temperature was similar for both groups. In addition, the amount of and circadian rhythm for each vigilance state and slow-wave activity were similar for the two groups. This study demonstrates that the CCK-A receptor might play a role in affecting the level of motor activity, adding hyperphagia, and the circadian rhythm of large movement in these rats prior to the manifestation of NIDDM. In contrast, a CCK-A receptor deficiency does not appear to affect sleep or body temperature in these rats.

Thiamine deficiency-induced disruptions in the diurnal rhythm and regulation of body temperature in the rat.

In the present study, diurnal rhythm and regulation of body temperature were monitored during and several weeks following pyrithiamine-induced thiamine deficiency (PTD group, n=8) or pairfeeding (control group, n=9). A significant decline of core body temperature and a disruption of its diurnal rhythm were observed at varying stages of PTD treatment. Following thiamine administration and return to thiamine-fortified chow, body temperature continued to fall and several days transpired before body temperature and its diurnal rhythm were returned to normal. When exposed to warm and cold environments, no significant group differences were observed in either the maximum temperature change or the time elapsed to reach maximal temperature change. Histological examination revealed necrotic lesions in thalamus and mammillary body in the PTD group characteristic of Wernicke's encephalopathy. No significant damage was observed in the medial preoptic and suprachiasmatic nuclei, brain regions involved in the regulation of body temperature and circadian rhythm. These findings suggest that hypothermia and disruption of the diurnal rhythm of body temperature can be reversed by restoration of adequate thiamine levels and are related to biochemical and physiological disturbances rather than gross structural changes.

Chronic orthostatic and antiorthostatic restraint induce neuroendocrine, immune and neurophysiological disorders in rats

The tail-cast suspension rat model has been developed in ground laboratories interested in space physiology for extensive study of mechanisms causing the pathophysiological syndrome associated with space flights. We used individually-caged male rats to explore the effects of acute and chronic (7d) orthostatic restraint (OR) and head-down anti-orthostatic restraint (AOR) on a series of physiological variables. The acute restraint study showed that (1) the installation of the OR device induced an acute reaction for 2 days, with a substantial rise in ACTH (x2) and CORT (x6), and that (2) the head-down tilt from OR to AOR induced (i) within 10 min and lasting 60 min a 2-fold rise in the intra-cerebro-ventricular pressure (Picv) monitored with an icv telemetric recording system, which receded to normal between 60 and 120 min; and (ii) within 30 min a short-lived 4-fold rise in plasma ACTH and CORT levels. Chronic OR induced (1) the suppression of the diurnal ACTH/CORT rhythm, with increased mean levels, especially for ACTH, (2) a degraded circadian locomotor activity rhythm manifested by a significant reduction in the spectral power of the 24h periodicity and a concomitant emergence of shorter (ultradian) periodicities, (3) an associated, but less pronounced alteration of the diurnal rhythm in body temperature; and (4) a marked increase in baseline plasma levels of IL-1β and an increased reactivity in cytokine release following an E. coli endotoxin (LPS) challenge. AOR induced (1) a similar obliteration of the circadian ACTH/CORT rhythm, (2) the loss of close correlation between ACTH and CORT, (3) a generalized increase in baseline plasma IL-1β levels and (4) more extensive degradation of the arcadian periodicity for both locomotor activity and, to a lesser extent, body temperature, replaced by dominant spectral powers for ultradian periodicities (3 to 10h). In conclusion, both experimental paradigms — but AOR more than OR — caused a blockade of the arcadian rhythmicity of major physiological variables, the loss of normal correlations between ACTH and CORT, and inflammatory-immune hyperreactivity. These pathophysiological disorders may all be parts of a complex chronic stress syndrome.

Diurnal rhythm in body temperature in different phases of the menstrual cycle.

Diurnal rhythm in body temperature in different phases of the menstrual cycle.

Circadian rhythms of serum thyrotrophin and body temperature in euthyroid individuals and their responses to warming.

The diurnal rhythms of body temperature and serum thyrotrophin (TSH) levels in euthyroid individuals behaved inversely to one another. An artificially induced rise in the body temperature of these individuals was accompanied by a fall in serum thyrotrophin levels, the amplitudes of their respective rhythms decreasing simultaneously. There was a marked correlation between the degrees of change in body temperature and circulating thyrotrophin levels respectively during warming. In normal subjects manipulation of the diurnal rhythm of body temperature brings about inverse alterations in the thyrotrophin rhythm.

Effect of diurnal rhythm of body temperature on muscular work

The effect of the diurnal rhythm of body temperature on the metabolic and thermoregulatory response to moderate work was studied in eight healthy, adult males. Work bouts were conducted at the occurrence of each subject's morning minimum (approx 0700 h) and afternoon maximum (approx. 4600 h) diurnal rhythm of body temperature. No significant differences were found between these time periods for resting and exercise oxygen uptakes, respiratory minute volume, metabolic heat production, or heart rates. However, resting and exercise rectal, mean skin, and mean body temperatures, and evaporative heat loss were significantly higher in the afternoon. The importance of the diurnal temperature rhythm on modifying the response of body temperature to exercise is discussed.

On the role of the pineal in thermoregulation in the pigeon.

Diurnal rhythm in body temperature of pigeons subjected to different experimental conditions (pinealectomized, sham-operated, melatonin-implanted, cold-exposed) was studied under a 12 h light and 12 h dark regimen. The body temperature of pigeons during photophase was higher than that during scotophase in the normal as well as every treatment group studied. Pinealectomized pigeons showed higher body temperature in the photophase as well as scotophase, than that of the normal and sham-operated birds when examined 2 or 3 weeks following the post-surgical acclimatization to 25 or 3 degrees C. However, subcutaneous implantation of melatonin pellets into pinealectomized pigeons nullified or even reversed the hyperthermic effect of pinealectomy. Exposure of pigeons to--18 degrees C for 280 min during photophase as well as scotophase, produced a marked drop in body temperature in pinealectomized, sham-operated and normal pigeons. The pinealectomized pigeons exhibited a higher body temperature than that of the sham-operated and normal ones when exposed to--18 degrees C during the photophase, but not during the scotophase. It was concluded that while the pineal is not necessary for maintaining the daily thermal rhythm in the avian body, it has a thermoregulatory role, in that it prevents rise in body temperature in warm (25 degrees C) acclimatized and chronic cold (3 degrees C) exposed birds. In acute short-term cold (--18 degrees C) exposure however, the temperature regulatory role of the pineal was not effective during the scotophase.

Trypanosoma brucei gambiense: Changes in body temperature rhythms of infected New Zealand albino rabbits

It has been shown by telemetry that uninfected New Zealand Albino rabbits exhibit a diurnal rhythm in body temperature. The maximum temperature occurred just before or during the dark period, and the lowest temperature during the light period. Preliminary data also suggested that there is a diurnal rhythm in water consumption, fecal and urine output. After these rabbits were infected with the African trypanosome, Trypanosoma brucei gambiense, body temperature was significantly decreased. The diurnal rhythm in body temperature was maintained; however, the period of maximum temperature shifted from the dark into the light. Although the evidence is very preliminary, it is also suggested that the diurnal rhythms in water uptake, fecal and urine output were also maintained. Finally, the shift in the high and low time points of the daily body temperature curve during infection were reversed after chemotherapy, and the original (uninfected) curved restored.

Diurnal rhythm of body temperature in night-shift workers

Ten employees working in three shifts at an iron foundry were under survey. Workers were engaged in each shift for five days. Diurnal change of the sublingual temperature was determined for a successive 20 days in summer as well as in winter.Regardless of season, diurnal change of body temperature in workers on the first shift (7:30-15:30) revealed a similar pattern to that of men in an ordinary routine.In the second (15:30-22:30) and the third (22:30-7:30) shifts, however, body temperatures rose at night. Body temperature was higher at 7 a.m. on the third shift, compared to other shifts. It was subsequently striking that an amplitude of the diurnal change was narrow in this shift. Under the circumstances, there were some working for more than 8 years, whose body temperature was lower in the afternoon than in the morning. It can therefore be inferred that biological rhythm is prone to synchronize with the rhythmic pattern of the mode of living of these particular workers. For the most part, however, no inversion of the rhythmic change was seen on night-shift work.On each shift, the mean temperature on a day tended to be higher in summer than in winter, and, especially, a significant difference between seasons was observed on the third shift.In its mean and variance, an amplitude of diurnal change had the tendency to lessen on the third shift compared to other shifts regardless of season.

Circadian variations in human thermoregulatory responses.

ARTICLESCircadian variations in human thermoregulatory responsesR. E. SmithR. E. SmithPublished Online:01 May 1969https://doi.org/10.1152/jappl.1969.26.5.554MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByCalcitonin receptors are ancient modulators for rhythms of preferential temperature in insects and body temperature in mammals12 February 2018 | Genes & Development, Vol. 32, No. 2Sleep and Heat Related Changes in the Cognitive Performance of Underground Miners: A Possible Health and Safety Concern2 November 2011 | Minerals, Vol. 1, No. 1A statistical model of the human core-temperature circadian rhythmEmery N. Brown, Yong Choe, Harry Luithardt, and Charles A. Czeisler1 September 2000 | American Journal of Physiology-Endocrinology and Metabolism, Vol. 279, No. 3Relationship between the daily rhythms of locomotor activity and body temperature in eight mammalian speciesRoberto Refinetti1 November 1999 | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, Vol. 277, No. 5Human core temperature minimum can be modified by ambient thermal transientsNeuroscience Letters, Vol. 173, No. 1-2The circadian rhythm of body temperaturePhysiology & Behavior, Vol. 51, No. 3Thermoregulatory circadian rhythms in the pouched mouse (Saccostomus campestris)Comparative Biochemistry and Physiology Part A: Physiology, Vol. 91, No. 1Day-night variation of thermoregulatory responses to intraperitoneal electric heating in ratsJournal of Thermal Biology, Vol. 12, No. 4Circadian change of heat loss in response to change in core temperature in ratsJournal of Thermal Biology, Vol. 11, No. 4Circadian variation of preferred environmental temperature and body temperatureJournal of Thermal Biology, Vol. 10, No. 3Nocturnal temperature in affective disorderJournal of Affective Disorders, Vol. 4, No. 1Temperature and heat flow variations during the menstrual cycle: Breasts and extremetiesJournal of Thermal Biology, Vol. 6, No. 3Central peripheral temperature gradientThe American Journal of Surgery, Vol. 140, No. 5Effect of diurnal rhythm of body temperature on muscular workJournal of Thermal Biology, Vol. 3, No. 4 More from this issue > Volume 26Issue 5May 1969Pages 554-560 Copyright & PermissionsCopyright © 1969 the American Physiological Societyhttps://doi.org/10.1152/jappl.1969.26.5.554PubMed5781606History Published online 1 May 1969 Published in print 1 May 1969 Metrics

Adjustment of the diurnal rhythm in body temperature by a transposition across the longitudes with a moderate speed.

Diurnal rhythm in body temperature and heart rate of 12 healthy athletes were recorded during a TransPacific voyage from Japan to the west coast of the United States. The speed of the ship was 14-16 knots which caused shortening of the actual length of a day by 32 minutes. The ratio of the lag of change in diurnal body temperature rhythm did not seem to be constant throughout the voyage. The adjustment of the rhythm to a new local time seemed to occur slowly during the first few days but fairly fast after the second week on the ship. During the voyage the rhythm was approximately 2 hours behind the typical temperature rhythm of the local time, and the rhythm could follow the new environmental routines in 3 or 4 days after arrival in USA. The results obtained suggest that the intrinsic biological rhythm formed during a longer period of time resists greatly distortion by a new environmental rhythm even with moderate speeds in trans·position. The diurnal rhythm in body function appears to adapt fairly rapidly to new environmental routines, although there are some literatures showing that the rhythm is hardly disturbed by a displacement or an inversion of the daily routines of living 1 ' 2 '· Sasaki 3 ' reported that there was apparently no difference between the diurnal change in body temperature and the external periodicity of living with a slower transposition across the longitudes, but with a faster speed of transposition which resulted in change of a day by approximately 30 minutes one could see a disparity between the external periodicity and the diurnal rhythm. In this latter case, apparently three days seem to be neces­ sary before the subjects' diurnal body rhythm is adjusted to the new environmental routine. Data observed for quickest transposition by a jet flight

Human circadian rhythms.

Human circadian rhythms.

Body temperature and fertilization in the cow.

Rectal temperatures of 934 Jersey and Australian Illawarra Shorthorn dairy cows were recorded during summer months im¬ mediately before artificial insemination. They ranged from 98-8°F to 105-0°F (mean 101-6 ± 0-9°F) and were related directly to stage of oestrus, supporting an earlier report of a thermal response at oestrus. Thus, the temperature of the cow's genitalia may be high during oestrus; and the sperms may be subjected to such environment for several hours after insemination. In addition, the data support the hypothesis that the normal diurnal rhythm of body temperature is restored some hours before ovulation

XII.—The Effect of changing the Daily Routine on the Diurnal Rhythm in Body Temperature

To determine whether the diurnal variation in body temperature is due to the combined effects of the various influences which are known to act upon it, such as muscular exercise, the ingestion of food, sleep, etc., or is present independently of these, the daily routine of the individual who is the subject of the experiment may be reversed artificially by causing him to work during the night and rest and sleep during the day, or it may be modified in another way, viz. by rapidly changing his longitude in a journey from west to east, or vice versa. If the temperature of the body is dependent on the influences mentioned, then a total reversal of the daily routine, or any modification of it, should produce a corresponding change in the diurnal temperature curve.