Cisplatin is one of the most commonly used chemotherapeutic drugs; however, toxicity and tumor resistance limit its use. Studies using murine models and human subjects have shown that the time of day of cisplatin treatment influences renal and blood toxicities. We hypothesized that the mechanisms responsible for these outcomes are driven by the circadian clock. We conducted experiments using wi...

Chronotherapeutics aim at treating illnesses according to the endogenous biologic rhythms, which moderate xenobiotic metabolism and cellular drug response. The molecular clocks present in individual cells involve approximately fifteen clock genes interconnected in regulatory feedback loops. They are coordinated by the suprachiasmatic nuclei, a hypothalamic pacemaker, which also adjusts the circ...

INTRODUCTION It has been known for a long time that the efficiency and toxicity of drugs change during a 24-h period. However, the molecular mechanisms involved in these processes have started to emerge only recently. AREAS COVERED This review aims to highlight recent discoveries showing the direct role of the molecular circadian clock in xenobiotic metabolism at the transcriptional and post-...

The 2017 Nobel Prize for Physiology or Medicine, awarded for the discoveries made in the past 15 years on the genetic and molecular mechanisms regulating many physiological functions, has renewed the attention to the importance of circadian rhythms. These originate from a central pacemaker in the suprachiasmatic nucleus in the brain, photoentrained via direct connection with melanopsin containi...

To examine the influence of amikacin-induced acute renal damage on the urinary excretion of furosemide and the time-dependent variation in the urinary amount of the agent, amikacin (1.2 g/kg) was given intraperitoneally to Wistar rats. Study I: Three percent b.w. of 1% NaCl solution was given orally before and after amikacin treatment, and an 8-hour urine for N-acetyl-beta-D-glucosaminidase (NA...

The influence of morphine dosing time on analgesic effect after acute or chronic treatment, recovery of analgesic effect after once developed tolerance, and their pharmacological mechanisms were investigated in ICR male mice under a 12-h light/dark cycle (light on from 7:00 AM to 7:00 PM). There was a significant 24-h rhythm in the latency of thermal response at 30 min after morphine injection....

BACKGROUND Mesial temporal lobe epilepsy (mTLE) has been suggested to follow a circadian rhythm. Previous research found an afternoon peak in mTLE seizure occurrence. We evaluated the pattern of seizure occurrence in patients with well-localized mTLE and hypothesized that peak seizure frequency would occur in the afternoon, and that this pattern would not be altered by age, gender, or seizure f...

The influence of dosing time on the antitumor effect and the rhythm disturbance effect of melatonin (MLT) was investigated in ICR male mice under a light/dark (12:12) cycle. In tumor-bearing mice, the antitumor effect of MLT (1 mg/kg intraperitoneal) was most effective in the dark phase; and the rhythm disturbance effect of MLT on the locomotor activity was more serious in the light phase than ...

BACKGROUND The pharmacokinetic and pharmacodynamic characteristics of opioids vary throughout the day, as demonstrated for oral morphine in chronic pain. However, little is known about the chronobiology of intrathecal lipid soluble opioids used for labor analgesia. The aim of this prospective study was to determine whether the duration of action of intrathecally administered sufentanil is influ...

Protective effect of valsartan (Val), an angiotensin II (AII)-receptor blocker (ARB), against organ damage is reported to depend on the dosing time in hypertensive patients. Dosing-time-dependent effect of Val on survival of stroke-prone spontaneously hypertensive rats (SHRSP) under a 12-h lighting cycle was examined. Val (4 mg/kg per day) and olmesartan medoxomil (OM) (1 mg/kg per day), anothe...