Reversed-phase high-performance liquid chromatographic determination of caffeine and its N-demethylated metabolites in dog plasma

Tse, Francis L. S.; Szeto, Daniel W.

doi:10.1016/s0378-4347(00)84227-9

Cited by 31 publications

(1 citation statement)

References 12 publications

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“…The concentrations of caffeine, theophylline, paraxanthine and theobromine were determined essen tially by the methods of Bonati et al [8] and Tse et al [9], with minor modifications as described previously [6,7). Briefly, after extraction with chloroforrmisopropyl alcohol (75:25, v/v), a sample in 0.005 M sodium acetate buffer, pH 5, was injected into a 10-pm pBondapak C|8 column, with a mobile phase of 0.005 M sodium acetate buffer (pH 5):mcthyl alcohol:acetonitrile:tetrahydrofuran (92.5:3:2.8:1.7, v/v).…”

Section: Methodsmentioning

confidence: 99%

Effects of Maternal Caffeine Ingestion on the Perinatal Cerebrum

Tanaka¹,

Nakazawa²,

Arima³

1987

Neonatology

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The cerebra of fetal rats from dams given 0.04 or 0.02% caffeine in drinking water ad libitum before and/or during pregnancy were examined on gestational day 21. A low placental weight was induced by caffeine ingestion for a long time throughout premating and pregnancy. A greater reduction in the fetal weight of the cerebrum than that of the body was observed with caffeine ingestion during pregnancy of levels of 1.5–3.0 μg caffeine/ml or g wet weight in dams and fetuses. In the cerebra of offspring, the levels of caffeine and theophylline did not change for 4 h after birth, and theophylline was not detected at all after intraperitoneal injection of caffeine. Thus, maternal caffeine should be warned against the fetal cerebral function.

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Section: Methodsmentioning

confidence: 99%

Effects of Maternal Caffeine Ingestion on the Perinatal Cerebrum

Tanaka¹,

Nakazawa²,

Arima³

1987

Neonatology

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Caffeine induces cardiac and other malformations in the rat

et al. 1987

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At various gestational periods, caffeine was injected intra-arterially or intraperitoneally into pregnant rats. The teratogenic effects of caffeine on the fetal heart were dose dependent and detectable at relatively low concentrations. The most susceptible stage was during septation of the heart. The most common cardiovascular malformation was ventricular septa1 defect. Extracardiovascular anomalies, such as decreased thymic weight and degeneration of the lens, were found in all fetuses; skeletal malformations were found in some fetuses.

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Effects of obesity and ancillary variables (dialysis time, drug, albumin, and fatty acid concentrations) on theophylline serum protein binding

Shum

Jusko

1989

Biopharm & Drug Disp

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The effect of obesity on the serum protein binding of theophylline was investigated in man and rat along with other ancillary variables such as dialysis time, theophylline concentration, albumin concentration, and fatty acid type and concentration. The percent binding of theophylline first increased with dialysis time, reached equilibrium over 2 to 6 h, then diminished. This decrease was not due to instability of theophylline. Theophylline binding was linear over a concentration range of 15 to 150 micrograms ml-1. A similar degree of binding was found in normal humans (44.4 +/- 1.0%) and rats (41.5 +/- 0.5%). The binding ratio (bound/free) of theophylline was proportional to the albumin concentration (1 to 5%) and yielded a binding parameter (NK) of 1.47 x 10(-3) M-1. Over a normal physiological range, individual and mixed fatty acids had minimal effects on theophylline binding to albumin. However, binding significantly decreased as fatty acid (FFA) concentrations increased. The magnitude of the effect appeared to parallel the carbon chain number of the fatty acid. Theophylline binding in obese subjects decreased to a mean (SD) of 35.8 +/- 8.0 per cent compared to 43.0 +/- 6.1 per cent in normal subjects (p less than 0.05). Similar decreases were found in normal versus obese rats and in the saliva: serum ratio following theophylline administration to normal and obese human subjects. Obesity causes a moderate decrease in serum binding of theophylline which may be attributed to increased FFA rather than in vitro artifacts.

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Reversed-phase high-performance liquid chromatographic determination of caffeine and its N-demethylated metabolites in dog plasma

Cited by 31 publications

References 12 publications

Effects of Maternal Caffeine Ingestion on the Perinatal Cerebrum

Effects of Maternal Caffeine Ingestion on the Perinatal Cerebrum

Caffeine induces cardiac and other malformations in the rat

Effects of obesity and ancillary variables (dialysis time, drug, albumin, and fatty acid concentrations) on theophylline serum protein binding

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