Human circadian rhythms in temperature, trace metals, and blood variables

Abstract

The literature supports the concept that circadian changes in body temperature reflect changes in the thermoregulatory set point. We were interested in studying the relationship between the circadian rhythm in body temperature and 24-h variations in plasma concentrations of iron, zinc, circulating leukocyte counts, and plasma interleukin 1 (IL-1) activity. Eight healthy men were studied for two separate 48-h sessions. Rectal temperature, plasma iron and zinc concentrations, plasma IL-1 activity, circulating leukocyte counts, and several other blood variables were monitored. Circadian rhythms in temperature, trace metals, and various leukocyte populations were demonstrated. The 24-h pattern of changes in plasma concentrations of iron and zinc approximate an inverse relationship with rectal temperature. Although we were unable to detect any IL-1 activity in human plasma collected at 4-h intervals, the daily changes in plasma trace metal concentrations and the variations in leukocyte populations may provide indirect evidence for a daily variation in local (e.g., in liver) or central nervous system release of IL-1.

Role of nitric oxide in inflammatory diseases

“…It involves a variety of protein and carbohydrate adhesion molecules on both endothelial cell and the neutrophil, and is regulated by messenger molecules released by cells in the injured area, including the endothelial cells. These messengers are collectively termed chemoattractants (also termed chemotaxins or chemotactic factors) (Scales et al, 1988).…”

“…In the next stage, via still other adhesion molecules, a narrow projection of the neutrophil is inserted into the space between two endothelial cells, and the entire neutrophil squeezes through the endothelial wall and into the interstitial fl uid. In this way, huge numbers of neutrophils migrate into the infl amed area and move toward the microbes (Scales et al, 1988).…”

Daily expression of clock genes in whole blood cells in healthy subjects and a patient with circadian rhythm sleep disorder

“…Figure 3 indicates that sleep-wake rhythm is irregular before treatment; however, the daily profiles of body temperature were normal. Generally, healthy human subjects show daily variations of body temperature characterized by temperature being lowest before waking in the morning (3:00 -5:00) and highest in the early evening (15:00 -18:00) (35). Figure 4 shows the daily profiles of melatonin and cortisol levels in the above patient before and after the treatments.…”

“…In humans, sleep-wake, hormonal secretion (melatonin, cortisol) (6,36), and autonomic cycles (e.g., body temperature, blood pressure, peak flow) (14,32,35) are regulated by the circadian clock, which is synchronized with the 24-h day by environmental time cues, especially light (16). In the rodent brain, the center of the circadian clock is located principally in the suprachiasmatic nucleus (SCN) of the hypothalamus and oscillates self-sustained (43).…”

Development and validation of a ultra performance LC‐ESI/MS method for analysis of metabolic phenotypes of healthy men in day and night urine samples

“…Most mammals have a circadian rhythm, which is controlled by a circadian clock. In human, sleep to wake, hormonal secretion [27] and autonomic cycle, such as body temperature, blood pressure [28], are regulated by the circadian rhythm, which is synchronized by environmental time cues, especially light [29]. The mammalian clock genes appear to regulate circadian expression not only in the suprachiasmatic nucleus (SCN) but also in other peripheral tissues [30].…”