Circadian and Circannual Changes in Nephrotoxic Effects of Heavy Metals and Antibiotics

Cal, J. C.; Dorian, C; Cambar, J.

doi:10.1016/b978-0-08-034135-4.50007-1

Cited by 33 publications

(10 citation statements)

References 82 publications

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“…MTX, being an acid, is theoretically, excreted with a variable elimination rate, because the urinary pH is circadian (12).…”

Section: Discussionmentioning

confidence: 99%

An approach for determination of chronopharmacokinetic parameters of methotrexate

Mansour

1997

European Journal of Drug Metabolism and Pharmacokinetics

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In classical pharmacokinetic studies, the organism is represented by one or several compartments described by a system of linear differential equations with constant coefficients. A system of linear differential equations can not describe the compartmental model in the presence of chronobiological variations. The purpose of this study is to calculate the chronopharmacokinetic parameters of Methotrexate, which presents this type of variation.

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“…MTX, being an acid, is theoretically, excreted with a variable elimination rate, because the urinary pH is circadian (12).…”

Section: Discussionmentioning

confidence: 99%

An approach for determination of chronopharmacokinetic parameters of methotrexate

Mansour

1997

European Journal of Drug Metabolism and Pharmacokinetics

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“…The circadian change in plasma CL rate of the drug could be caused by that in the renal filtration rate and/or biliary output. The maximum glomerular filtration rate is closely related to the time-point with the most rapid plasma CL of drugs with low lipid solubility such as MTX (16). There fore, higher renal blood flow and filtration during the ac tive period of animals may contribute to the increased rate of renal MTX CL.…”

Section: Discussionmentioning

confidence: 99%

Alpha-1 Adrenoceptor Subtypes in Canine Aorta

Song

Nakano

Ohdo

et al. 1993

Japanese Journal of Pharmacology

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ABSTRACT-The circadian rhythms of the toxicity and the pharmacokinetics of methotrexate (MTX), as well as the effects of manipulation of feeding schedule on the rhythms, were investigated in mice. Male ICR mice were housed under a standardized light-dark cycle (12:12) with food and water ad libitum (ALF) or under the time-restricted feeding (TRF) schedule (8 hr during the light phase) for 1 day or 14 days before the drug administration.The animals received MTX (100 mg/kg, i.p.) once daily for 7 days in the toxicity studies and a single dose of MTX (100 mg/kg, i.p.) for the kinetic studies. Under the ALF, a significant dos ing time dependency was demonstrated for the toxicity of MTX with a longer survival time for the middark dosing and a shorter one for the midlight dosing. The MTX kinetics also showed a significant rhythm, with the highest clearance at middark and the lowest one at midlight. The rhythm in MTX kinetics well coincided with that in the toxicity of the drug. The TRF had a marked influence on the rhythms of MTX kinetics and toxicity. Thus, the timing of dosing is important in the kinetics and the toxicity of MTX in mice, and the manipulation of feeding schedule can modify the rhythm of the toxicity by changing that of the MTX kinetics.

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“…Furthermore, epoxides are subject to nonenzymatic rearrangement or direct excretion. There are significant diurnal rhythms in hepatic enzyme activity and renal function (Holcslaw et al, 1975;Halberg and Halberg, 1984;Cal et al, 1986). The diurnal variations in these physiological functions may be the mechanism underlying the diurnal variations in plasma TNP-470 concentration.…”

Section: Discussionmentioning

confidence: 99%

Optimizing the Dosing Schedule of TNP-470 [O-(Chloroacetyl-carbamoyl) Fumagillol] Enhances Its Antitumor and Antiangiogenic Efficacies

Koyanagi¹,

Nakagawa²,

Kuramoto³

et al. 2003

J Pharmacol Exp Ther

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Many drugs vary in potency and/or toxicity according to the time of day when they are administered. In this study, we investigated whether antitumor efficacy of angiogenesis inhibitor, fumagillol], could be improved by optimizing the dosing schedule. Tumor-bearing mice were housed under standardized light/dark cycle conditions (lights on at 7:00 AM, off at 7:00 PM) with food and water ad libitum. The antitumor effect of TNP-470 (30 mg/kg s.c.) was more potent in mice injected with the drug at the early light phase than it was when administered at the early dark phase. The diurnal change in the antitumor effect of TNP-470 was parallel to that in its antiangiogenic activity. The variation in the effects of TNP-470 was closely related to the diurnal variations in its inhibitory action on methionine aminopeptidase activity in tumor masses. There was a significant dosing time-dependent change in the concentration of TNP-470 in plasma. The higher concentration of TNP-470 in plasma was observed when its antitumor and antiangiogenic activities were increased. These results suggest that therapeutic efficacy of TNP-470 can be enhanced by choosing the most appropriate time of day to administer the drug.Angiogenesis, the formation of new vessels from pre-existing vessels, has been shown to be necessary for the progression and metastasis of malignant tumors (Folkman, 1971). Tumors require a supply of nutrients, oxygen, and various growth factors. In addition, they utilize the newly formed blood vessels as conduits to disseminate invasive tumor cells. Because the growth and metastasis of malignant tumors are dependent on angiogenesis, a novel anticancer treatment has been developed in which tumors are regressed by prolonged inhibition of angiogenesis. In comparison with conventional chemotherapy, antiangiogenic therapy has a number of clinical advantages, including low toxicity, lack of drug resistance, and easy access of the drugs to the targeted endothelial cells (Boehm et al., 1997). A variety of antiangiogenic agents are currently undergoing clinical trails for dormancy therapy of tumors.TNP-470 (AGM-1470), a synthetic analog of fumagillin, has been shown to prevent angiogenesis by arresting the endothelial cell cycle (Hori et al., 1994), and it potently inhibits tumor growth and metastasis in a wide range of in vivo tumor models (Ingber et al., 1990;O'Reilly et al., 1995). TNP-470 arrests the endothelial cell cycle by inhibiting the activities of type II methionine aminopeptidase (MetAP-2), which appears to play an important role in cell cycle initiation (Griffith et al., 1997;Sin et al., 1997). Although TNP-470 has significant clinical advantages as a therapeutic agent for cancer treatment, its short serum half-life and dose-limiting side effects diminish the potency of this drug (Logothetis et al., 2001).One approach to increase the efficacy of pharmacotherapy is to administer drugs at a time of day when they are most effective and/or best tolerated. Daily rhythmic variations in biological functions such as se...

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Circadian and Circannual Changes in Nephrotoxic Effects of Heavy Metals and Antibiotics

Cited by 33 publications

References 82 publications

An approach for determination of chronopharmacokinetic parameters of methotrexate

An approach for determination of chronopharmacokinetic parameters of methotrexate

Alpha-1 Adrenoceptor Subtypes in Canine Aorta

Optimizing the Dosing Schedule of TNP-470 [O-(Chloroacetyl-carbamoyl) Fumagillol] Enhances Its Antitumor and Antiangiogenic Efficacies

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