Renal Excretion: Rhythms in Physiology and Pathology

Cambar, J.; Cal, J. C.; Tranchot, J.

doi:10.1007/978-3-642-78734-8_34

Cited by 16 publications

(8 citation statements)

References 64 publications

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“…Knowledge of renal chronobiology is particularly important for developing strategies entailing the chronotherapy of medications by enhancing desired effects and reducing kidney toxicity (i.e., renal chronotolerance) as recently reviewed (38,39).…”

Section: Circadun Rhythmicity In Renal Hemodynamcsmentioning

confidence: 99%

Circadian Rhythms of Renal Hemodynamics in Unanesthetized, Unrestrained Rats

Pons

Tranchot

L’Azou

et al. 1994

Chronobiology International

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Catheters were placed in the jugular vein and femoral artery of male Sprague-Dawley rats and connected to a specially designed perfusor for continuous constant infusion of 0.9% NaCl and a syringe to perform simultaneous and intermittent blood collections. This permitted continuous 24-h study of renal hemodynamics, estimated by inulin (Cin) and p-amino-hippuric acid (CPAH) clearances; Cin represents glomerular filtration rate and CPAH renal plasma flow. Animals were individually housed in metabolism cages in a controlled environment with light/dark 12:12 h. Urine was collected every 4 h (12:00, 16:00, 20:00, 24:00, 04:00, and 08:00) and blood sampled at the midpoint of urine collection periods. Urine and plasma sodium, potassium, inulin, and PAH were spectrophotometrically assessed. During continuous infusion of isotonic saline, Cin exhibited circadian changes with large decrease between 12:00 and 20:00 h (0.9 +/- 0.2 ml/min) and acrophase at 00:30 h. Rhythmicity in CPAH was similar with the minimum between 16:00 and 20:00 h (2.5 +/- 0.3 ml/min) and peak between 00:00 and 04:00 h (acrophase at 00:25 h). Water and electrolyte excretion were also circadian rhythmic with a similar nighttime enhancement and daytime minimum. Such circadian changes persisted during continuous 0.9% NaCl infusion for several consecutive days. The unanesthetized, unrestrained rat model enables investigations in renal chronopharmacology and chronotoxicology.

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Section: Circadun Rhythmicity In Renal Hemodynamcsmentioning

confidence: 99%

Circadian Rhythms of Renal Hemodynamics in Unanesthetized, Unrestrained Rats

Pons

Tranchot

L’Azou

et al. 1994

Chronobiology International

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“…Very few renal rhythms are solely dependent on exogenous sources, such as ingested food or water. Thus, the resultant excretion rhythms in human subjects and experimental animals living with ad libitum food intake are a combination of exogenous and endogenous influences (Camber et al, 1992). A study by Branchero et al (2006) shows that plasma urea was similar in well-fed and underfed lactating animals, suggesting that the protein requirements were met either by the diet or tissue mobilization, or both.…”

Section: Discussionmentioning

confidence: 97%

“…Urea blood concentration together with creatinine blood concentration is the most commonly used procedure for monitoring glomerular filtration rate in humans and animals. It is known that mammals have a circadian rhythm of urinary excretion and that the source of this rhythm is endogenous in origin (Camber et al, 1992). There are three possible sources for circadian variations in the excretion of a urinary constituent Á exogenous, , 1982).…”

Section: Discussionmentioning

confidence: 99%

Influence of lamb presence on daily rhythm in lactating ewes

Morgante

Stelletta

Gianesella

et al. 2008

Acta Agriculturae Scandinavica, Section A - Animal Science

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To determine the influence of lamb presence on the dairy ewes circadian system we monitored simultaneously 16 different parameters (insulin, glucose, total protein, urea, cholesterol, triglycerides, total bilirubine, calcium, phosphorus, magnesium, sodium, potassium, chloride, rectal temperature, respiratory rate and heart rate). Sixteen clinically healthy Sarda breed dairy ewes, divided into two groups, group A with their lambs and group B without their lambs, were used. Data collection was done at 3 hourly intervals over a 24-h period. Our results indicate that lamb presence influences ewes metabolism, inducing modifications of the acrophase and robustness of the rhythm of some physiological variables. Most variables lost the rhythmicity that they show in not pregnant and not lactating ewes. Lamb presence also influenced urea circadian rhythm: the time of urea peak was shifted from 16:00 to 12:24900:35 when ewes were housed with lambs, and on triglycerides circadian rhythm.

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“…[41] Drug elimination Renal physiological functions such as glomerular filtration, renal blood flow, urinary pH, and tubular resorption show a circadian time-dependent difference with higher values during daytime. [42] These rhythmic variations in renal functions may contribute to a circadian-dependent change in drug urinary excretion. The rhythmicity in urinary pH modifies drug ionization and may explain that acidic drugs are excreted faster after an evening administration as demonstrated for sodium salicylate [43] and sulfasylazine.…”

Section: Drug Absorptionmentioning

confidence: 99%

Chronomodulated drug delivery system: A comprehensive review on the recent advances in a new sub-discipline of ′chronopharmaceutics′

Bisht¹

2011

Asian J Pharm

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W ith the advancement in the field of chronobiology, modern drug delivery approaches have been elevated to a new concept of chronopharmacology, that is, the ability to deliver the therapeutic agent to a patient in a staggered profile. The mammalian circadian pacemaker resides in the paired suprachiasmatic nuclei and influences a multitude of biological processes, including the sleep-wake rhythm. Clock genes are the genes that control the circadian rhythms in physiology and behavior. Twenty-four hours rhythms are demonstrated for the function of physiology and the pathophysiology of diseases. The effectiveness and toxicity of many drugs vary depending on the dosing time. Such chronopharmacological phenomena are influenced by not only the pharmacodynamics, but also the pharmacokinetics of medications. The underlying mechanisms are associated with the 24-hour rhythms of biochemical, physiological, and behavioral processes under the control of the circadian clock. New technology for delivering medications precisely in a time-modulated fashion, by bedside or ambulatory pumps, is being developed to manage human diseases. From the point of view of pharmaceutics, the application of a biological rhythm to pharmacotherapy may be accomplished by the appropriate timing of conventionally formulated tablets and capsules, and a special drug delivery system, to synchronize the drug concentrations with the rhythms in the disease activity. Therefore, the present article gives an overview of the dosing time-dependent alterations in the therapeutic outcome and safety of the drug. The underlying mechanisms and usefulness are introduced from the point of view of chronopharmacology and chronotherapy.

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Renal Excretion: Rhythms in Physiology and Pathology

Cited by 16 publications

References 64 publications

Circadian Rhythms of Renal Hemodynamics in Unanesthetized, Unrestrained Rats

Circadian Rhythms of Renal Hemodynamics in Unanesthetized, Unrestrained Rats

Influence of lamb presence on daily rhythm in lactating ewes

Chronomodulated drug delivery system: A comprehensive review on the recent advances in a new sub-discipline of ′chronopharmaceutics′

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