Daily Rhythmic Variations Research Articles

Multi-omics Investigations in Endocrine Systems and Their Clinical Implications.

Innovative techniques such as the "omics" can be a powerful tool for the understanding of intracellular pathways involved in homeostasis maintenance and identification of new potential therapeutic targets against endocrine-metabolic disorders. Over the last decades, proteomics has been extensively applied in the study of a wide variety of human diseases, including those involving the endocrine system. Among the most endocrine-related disorders investigated by proteomics in humans are diabetes mellitus and thyroid, pituitary, and reproductive system disorders. In diabetes, proteins implicated in insulin signaling, glucose metabolism, and β-cell activity have been investigated. In thyroid diseases, protein expression alterations were described in thyroid malignancies and autoimmune thyroid illnesses. Additionally, proteomics has been used to investigate the variations in protein expression in adrenal cancers and conditions, including Cushing's syndrome and Addison's disease. Pituitary tumors and disorders including acromegaly and hypopituitarism have been studied using proteomics to examine changes in protein expression. Reproductive problems such as polycystic ovarian syndrome and endometriosis are two examples of conditions where alterations in protein expression have been studied using proteomics. Proteomics has, in general, shed light on the molecular underpinnings of many endocrine-related illnesses and revealed promising biomarkers for both their detection and treatment. The capacity of proteomics to thoroughly and objectively examine complex protein mixtures is one of its main benefits. Mass spectrometry (MS) is a widely used method that identifies and measures proteins based on their mass-to-charge ratio and their fragmentation pattern. MS can perform the separation of proteins according to their physicochemical characteristics, such as hydrophobicity, charge, and size, in combination with liquid chromatography. Other proteomics techniques include protein arrays, which enable the simultaneous identification of several proteins in a single assay, and two-dimensional gel electrophoresis (2D-DIGE), which divides proteins depending on their isoelectric point and molecular weight. This chapter aims to summarize the most relevant proteomics data from targeted tissues, as well as the daily rhythmic variation of relevant biomarkers in both physiological and pathophysiological conditions within the involved endocrine system, especially because the actual modern lifestyle constantly imposes a chronic unentrained condition, which virtually affects all the circadian clock systems within human's body, being also correlated with innumerous endocrine-metabolic diseases.

Circadian rhythm and health: dialogue between traditional Chinese medicine and modern medicine

Circadian rhythm refers to the daily rhythmic variations in an organism. The irregular lifestyles of modern humans have led to a high incidence of chronic diseases, highlighting an inseparable relationship between disrupted circadian rhythm and disease development. TCM has long discussed rhythmic variations, with records dating back to the Yellow Emperor's Inner Canon(Huang Di Nei Jing), which laid a rich theoretical foundation for the research on circadian rhythm. Modern medical research has provided a more comprehensive explanation of its molecular mechanisms. This article integrated the current understanding of circadian rhythm in both Chinese and western medicine, emphasizing the crucial relationship between rhythm regulation and disease treatment. By highlighting the interdisciplinary nature of the two fields, it offers new directions for exploring the field of chronomedicine.

Chrono-pharmaceutical approaches to optimize dosing regimens based on the circadian clock machinery

Daily rhythmic variations in biological functions affect the efficacy and/or toxicity of drugs: a large number of drugs cannot be expected to exhibit the same potency at different administration times. The “circadian clock” is an endogenous timing system that broadly regulates metabolism, physiology and behavior. In mammals, this clock governs the oscillatory expression of the majority of genes with a period length of approximately 24 h. Genetic studies have revealed that molecular components of the circadian clock regulate the expression of genes responsible for the sensitivity to drugs and their disposition. The circadian control of pharmacodynamics and pharmacokinetics enables ‘chrono-pharmaceutical’ applications, namely drug administration at appropriate times of day to optimize the therapeutic index (efficacy vs. toxicity). On the other hand, a variety of pathological conditions also exhibit marked day-night changes in symptom intensity. Currently, novel therapeutic approaches are facilitated by the development of chemical compound targeted to key proteins that cause circadian exacerbation of disease events. This review presents an overview of the current understanding of the role of the circadian biological clock in regulating drug efficacy and disease conditions, and also describes the importance of identifying the difference in the circadian machinery between diurnal and nocturnal animals to select the most appropriate times of day to administer drugs in humans.

Chrono-Pharmaceutical Approaches to Optimize Dosing Regimens Based on the Circadian Clock Machinery.

Daily rhythmic variations in biological functions affect the efficacy and/or toxicity of drugs: a large number of drugs cannot be expected to exhibit the same potency at different administration times. The "circadian clock" is an endogenous timing system that broadly regulates metabolism, physiology and behavior. In mammals, this clock governs the oscillatory expression of the majority of genes with a period length of approximately 24 h. Genetic studies have revealed that molecular components of the circadian clock regulate the expression of genes responsible for the sensitivity to drugs and their disposition. The circadian control of pharmacodynamics and pharmacokinetics enables 'chrono-pharmaceutical' applications, namely drug administration at appropriate times of day to optimize the therapeutic index (efficacy vs. toxicity). On the other hand, a variety of pathological conditions also exhibit marked day-night changes in symptom intensity. Currently, novel therapeutic approaches are facilitated by the development of chemical compound targeted to key proteins that cause circadian exacerbation of disease events. This review presents an overview of the current understanding of the role of the circadian biological clock in regulating drug efficacy and disease conditions, and also describes the importance of identifying the difference in the circadian machinery between diurnal and nocturnal animals to select the most appropriate times of day to administer drugs in humans.

Feeding frequency on Lophiosilurus alexandri: performance, hematology, and daily rhythms

ABSTRACT The aim of the present study was to evaluate the different feeding frequencies on the performance, hematology profile, daily rhythms of glucose and activities digestive enzymes for juvenile Lophiosilurus alexandri. Feeding frequency did not affect survival, final weight, daily weight gain (P > .05). Glucose showed a daily rhythmic variation, with the acrophase in the group F2 located at Zeitgeber Time (ZT) 12.51 h and at ZT 13.33 h in the group F5. The daily rhythms in digestive enzymes were also affected, especially chymotrypsin, whose activity was twofold higher in F5 than F2. Food ratio divided into a higher frequency along the day induces an increase in acid protease and chymotrypsin activities. Different feeding frequencies can influence hematology profile, daily rhythms of glucose and activities digestive enzymes. The production of juvenile L. alexandri can be successfully carried out adopting a feeding frequency of twice a day.

Daily Rhythmic Variations of Renal Molybdenum Hydroxylases in Male Rats

Daily Rhythmic Variations of Renal Molybdenum Hydroxylases in Male Rats

Ischemic stroke destabilizes circadian rhythms

BackgroundThe central circadian pacemaker is a remarkably robust regulator of daily rhythmic variations of cardiovascular, endocrine, and neural physiology. Environmental lighting conditions are powerful modulators of circadian rhythms, but regulation of circadian rhythms by disease states is less clear. Here, we examine the effect of ischemic stroke on circadian rhythms in rats using high-resolution pineal microdialysis.MethodsRats were housed in LD 12:12 h conditions and monitored by pineal microdialysis to determine baseline melatonin timing profiles. After demonstration that the circadian expression of melatonin was at steady state, rats were subjected to experimental stroke using two-hour intralumenal filament occlusion of the middle cerebral artery. The animals were returned to their cages, and melatonin monitoring was resumed. The timing of onset, offset, and duration of melatonin secretion were calculated before and after stroke to determine changes in circadian rhythms of melatonin secretion. At the end of the monitoring period, brains were analyzed to determine infarct volume.ResultsRats demonstrated immediate shifts in melatonin timing after stroke. We observed a broad range of perturbations in melatonin timing in subsequent days, with rats exhibiting onset/offset patterns which included: advance/advance, advance/delay, delay/advance, and delay/delay. Melatonin rhythms displayed prolonged instability several days after stroke, with a majority of rats showing a day-to-day alternation between advance and delay in melatonin onset and duration. Duration of melatonin secretion changed in response to stroke, and this change was strongly determined by the shift in melatonin onset time. There was no correlation between infarct size and the direction or amplitude of melatonin phase shifting.ConclusionThis is the first demonstration that stroke induces immediate changes in the timing of pineal melatonin secretion, indicating that cortical and basal ganglia infarction impacts the timing of melatonin rhythms. The heterogeneous direction and amplitude of melatonin shifts suggests that the upstream regulation of hypothalamic timekeeping is likely anatomically diffuse and mechanistically complex. Finally, our study exemplifies the use of pineal microdialysis to evaluate the effect of neurological diseases on circadian function.

Variations and interrelation between vasopressin and plasma osmolality in diabetic rats with insulin treatment

Although it is well known that plasma osmolality and plasma vasopressin (VP) levels in diabetes mellitus are higher than in non-diabetic conditions (and that these levels return to normality with insulin therapy), there are no existing studies which examine for insulin-dependent diabetes,either the persistence of daily rhythmic variations of VP or the relationship between this variation and daily osmotic oscillations. We have therefore examined nycthaemeral variations in both plasma osmolality and plasmaVP in normal (C), uncontrolled (D) and controlled insulin-dependent streptozotocin diabetic rats (DI). The uncontrolled streptozotocin treated rats presented, a loss of VP rhythmicity. together with higher values of VP than in both normal and controlled diabetic rats. The VP rhythm, however, could be restored with insulin treatment. Furthermore, the temporal VP/osmolality ratio in uncontrolled diabetic rats is higher than in normal rats, although this ratio does not show the daily rhythmic pattern that is present in both normal and diabetic rats treated with insulin.This may indicate that the lack of rhythmicity in osmotic regulation is responsible for the absence of a circadian rhythm in VP. As a result, we conclude that in uncontrolled diabetic rats, the higher VP levels and the loss of VP circadian rhythmicity could be due to a higher sensitivity in the osmoregulatory system, together with an absence of circadian variation of this system. This circadian variation could be responsible for the plasma VP rhythmicity in both normal and controlled diabetic rats.

Daily rhythmic variations in young mice liver antioxidant system and serum nitrite in response to exercise

Daily rhythmic variations in young mice liver antioxidant system and serum nitrite in response to exercise

Daily rhythmic and non-rhythmic variations of follitropin, lutropin, testosterone, and sex-hormone-binding globulin in men.

The circadian rhythmic variations of the serum concentrations of follitropin, lutropin, sex-hormone-binding globulin and testosterone, the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, and the salivary concentration of testosterone were investigated in a group of 13 apparently healthy men. Venous blood and salivary specimens were collected at 4-h intervals over a 24-h period. The circadian rhythms were studied by using a periodic function resulting from the sum of two cosine functions with periods of 24 and 12 h. The serum concentrations of follitropin and lutropin showed no significant rhythmic variations. For the salivary concentration of testosterone and for the ratio between the serum concentrations of testosterone and sex-hormone-binding globulin, only the cosine function with a period of 24 h was significant. Serum concentrations of sex-hormone binding globulin and testosterone were significantly affected by 24- and 12-h rhythmic components. Of the quantities studied, the salivary concentration of testosterone showed the greatest daily rhythmic variation (28.8% of the mean estimated over rhythm).

Circadian rhythmic variations in serum concentrations of clinically important lipids

Twenty-five apparently healthy adults (13 men and 12 women), mean age 29.5 years (SD 3.6 years), served as subjects in a 24-h study conducted in Barcelona (Spain) in spring of 1990. Six blood samples were collected from each subject at 4-h intervals over a 24-h period, beginning at 1000. The oral temperature was measured at 2-h intervals to facilitate an independent biological time reference. The serum concentrations of apolipoprotein (apo) A-I, apo B, cholesterol, high- and low-density lipoprotein cholesterol, and triglyceride were measured. The circadian rhythms of these quantities were studied with use of a periodic function resulting from the sum of two cosine functions of 24 and 12 h. For serum concentrations of apo A-I and apo B, only the 24- or 12-h components, respectively, were significant. However, the other quantities studied were significantly affected by both rhythmic components. The maximum daily rhythmic variation ranged from 5% (with respect to the daily mean) for apo A-I to 63% for triglyceride concentration. In all cases except triglyceride, the daily maximum values were measured in the afternoon samples, near the time of maximum oral temperature.

Daily rhythmic variations in histamine in human blood.

We examined whether or not normal subjects have rhythmic changes of blood histamine levels. Daily predictable variations are present with 3 maxima and 3 minima and acrophase at 09.13. The significance of these changes is presently unknown.

Circadian variation in mitotic index of primary spermatogonia in the adult frog(Rana esculenta)

Abstract Circadian rhythmicity in the average proliferation rate of the primary spermatogonial cell crop in the frog testis was studied by the stathmokinetic method. Colchicine was used to specifically block cells after they enter metaphase. The in vivo mitotic activity of primary spermatogonia was studied in three different periods of the year and was analyzed at 8 time points of the 24‐hour day. Circadian variations were suggested in all three periods of the year. Mitotic activity of the primary spermatogonia was also analyzed in vitro at 16 time points through a 48‐hour experimental period. Daily rhythmic fluctuations in the division rate of primary spermatogonia were observed. Thus, the proportion of cells in mitosis within the primary spermatogonial cell crop of the frog testis exhibits not only significant seasonal variations (as reported elsewhere), but also a daily rhythmic variation. The percent difference between low and high values of mitotic circadian rhythm varies with season.

Rhythmic variations of valine and leucine decarboxylation in rat diaphragm

Daily rhythmic variations of valine and leucine decarboxylation in the rat diaphragm were measured. Both valine and leucine decarboxylation increased during the hours of darkness and decreased during hours of light. Hypophysectomy eliminated the daily variation of decarboxylation. When food is available ad lib. to normal rats, the time of most active feeding coincides with the hours of darkness. Therefore, the period of darkness and maximum feeding coincides with the maximum oxidation of these two essential amino acids, valine and leucine, by diaphragm, and an active pituitary appears to be necessary to maintain this relationship. This model can be used to study interrelationships of behavioral, neurohumoral, and metabolic rhythms.

Daily rhythmic variation and liver drug metabolism in rats

Four substrates (hexobarbital, imipramine, p-nitroanisol and aminopyrine) are metabolized by rat liver (9000 g fraction) with a rhythm showing a minimum or a maximum between 10.00 a.m. and 2.00 p.m. The minimum was reached during light and the maximum during darkness when the illumination schedule was respectively from 6.30 a.m. to 6.30 p.m. or from 6.30 p.m. to 6.30 a.m. The change in drug metabolism corresponds also to a change in the level of plasma corticosterone. The possibility that neuroendocrine factors may be responsible for the daily rhythm of drug metabolism is discussed.

Daily rhythmic variations in blood coagulation times in rats.

AbstractWith all other environmental factors rigidly standardized, normal Sprague‐Dawley rats were maintained under the following schedules: (1) 12 hours of artificial light 0600 to 1800 alternating with 12 hours of darkness‐LD; (2) reversal of the first‐DL; (3) constant darkness‐DD, and (4) constant illumination‐LL.After the animals had been under a specific lighting regimen for at least three weeks, blood coagulation times were determined on separate groups of 8 to 16 animals at bi‐hourly intervals during a 24‐hour period. Significant daily fluctuations or rhythms in coagulation times under all lighting conditions were found by plotting each of the bi‐hourly mean values as a function of time. The temporal phasing of all rhythms in LD, DL, LL and DD were similar. The major changes found in the different lighting schedules involved overall magnitude, e.g., the overall 24‐hour mean coagulation time for rats maintained in LL was 21% greater than for rats maintained in DD. Although total adrenalectomy or adrenal medullectomy did not abolish the characteristic LD rhythm, there was about a 100% decrease in the mean 24‐hour coagulation time of LD adrenalectomized animals when compared to normal LD animals. No significant decrease was seen in adrenal demedullectomized animals when similarly compared with normal LD animals.

Daily Rhythmic Variation of Blood Coagulation Times in Four Species of Rodents

Previous articleNext article No AccessDaily Rhythmic Variation of Blood Coagulation Times in Four Species of RodentsRobert A. EversonRobert A. Everson Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 33, Number 4Oct., 1960 Article DOIhttps://doi.org/10.1086/physzool.33.4.30152672 Views: 1Total views on this site Citations: 9Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). Copyright 1960 University of ChicagoPDF download Crossref reports the following articles citing this article:Giuseppe Piccione, Claudia Giannetto State of the art on daily rhythms of physiology and behaviour in horses, Biological Rhythm Research 42, no.11 (Jan 2011): 67–88.https://doi.org/10.1080/09291016.2010.491247G. Piccione, M. Percipalle, F. Fazio, V. Ferrantelli, G. Caola Circadian variation of blood clotting time and circulating vitamin K in the athletic horse, Comparative Clinical Pathology 14, no.22 (Sep 2005): 86–89.https://doi.org/10.1007/s00580-005-0564-4Shuichi HAMADA, Tetsu NISHIKAWA, Norihide YOKOI, Tadao SERIKAWA TM Rats: A Model for Platelet Storage Pool Deficiency., Experimental Animals 46, no.33 (Jan 1997): 235–239.https://doi.org/10.1538/expanim.46.235Erhard Haus, Marsha Cusulos, Linda Sackett-Lundeen, Jacqueline Swoyer Circadian Variations in Blood Coagulation Parameters, Alpha-Antitrypsin Antigen and Platelet Aggregation and Retention in Clinically Healthy Subjects, Chronobiology International 7, no.33 (Jul 2009): 203–216.https://doi.org/10.3109/07420529009056976Graziella Soulban, Gaston Labrecque, Pierre M. Bélanger Temporal Variation in the Effects of Warfarin on the Vitamin K Cycle, Chronobiology International 7, no.5-65-6 (Jul 2009): 403–411.https://doi.org/10.3109/07420529009059151G. Soulban, G. Labrecque Circadian rhythms of blood clotting time and coagulation factors II, VII, IX and X in rats, Life Sciences 45, no.2525 (Jan 1989): 2485–2489.https://doi.org/10.1016/0024-3205(89)90015-5Michael Cohen, David J. Simmons, J.Heinrich Joist Diurnal hemostatic changes in the rat, Thrombosis Research 12, no.66 (Jun 1978): 965–971.https://doi.org/10.1016/0049-3848(78)90052-X Lee A. Rigg Levels of Prothrombin Complex Factors in the Chipmunk (Eutamias quadrivittatus), Physiological Zoology 40, no.22 (Sep 2015): 143–148.https://doi.org/10.1086/physzool.40.2.30152449Lawrence E. Scheving, John E. Pauly Daily rhythmic variations in blood coagulation times in rats, The Anatomical Record 157, no.44 (Apr 1967): 657–665.https://doi.org/10.1002/ar.1091570411