Biomaterial Database

Effects of administration of estrogen or diphenylhydantoin on the kinetics of diphenylhydantoin in man. 1975

J A Fernandez-Pol, and A A Zaninovich

The rate of disappearance of 131I-diphenylhydantoin (131I-DPH) from plasma and its hepatic uptake were studied during a control period and after estrogen administration in ten normal human subjects. Four subjects were given DPH and were studied in the same fashion as the estrogen-treated group. After intravenous injection of a tracer dose of 131I-DPH (period of study: 30-150 min after 131I-DPH administration), the estrogen-treated group showed an increase in the plasma half-time, a decrease in the fractional turnover rate, and a decrease in the distribution space of 131I-DPH in comparison with control. The hepatic uptake was decreased in comparison with the control, which may be explained by an increase in the binding capacity of thyroxine-binding globulin (TBG) induced by estrogens. An increase in the distribution space of 131I-DPH was observed in subjects treated with diphenylhydantoin. Consequently, the clearance rate was increased. No change in half-time or in turnover rate was observed. The hepatic uptake in the DPH-treated group was increased in comparison with control. This may be explained by a displacement of 131I-DPH by DPH from the binding sites of TBG. This study showed, therefore, that changes in the binding capacity of TBG are associated with alterations in the peripheral metabolism of 131I-DPH in man.

UI	MeSH Term	Description	Entries
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D010672	Phenytoin	An anticonvulsant that is used to treat a wide variety of seizures. It is also an anti-arrhythmic and a muscle relaxant. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. The mechanism of its muscle relaxant effect appears to involve a reduction in the sensitivity of muscle spindles to stretch. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs.	Diphenylhydantoin,Fenitoin,Phenhydan,5,5-Diphenylhydantoin,5,5-diphenylimidazolidine-2,4-dione,Antisacer,Difenin,Dihydan,Dilantin,Epamin,Epanutin,Hydantol,Phenytoin Sodium,Sodium Diphenylhydantoinate,Diphenylhydantoinate, Sodium
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D013975	Thyroxine-Binding Proteins	Blood proteins that bind to THYROID HORMONES such as THYROXINE and transport them throughout the circulatory system.	Thyroxine Transport Protein,Thyroxine-Binding Protein,Thyroxine Binding Protein,Thyroxine Binding Proteins
D045166	Estradiol Congeners	Steroidal compounds related to ESTRADIOL, the major mammalian female sex hormone. Estradiol congeners include important estradiol precursors in the biosynthetic pathways, metabolites, derivatives, and synthetic steroids with estrogenic activities.	Estradiol Congener,Estrogen Analog,Estrogen Analogue,Synthetic Estrogen,Estrogen Analogs,Estrogen Analogues,Estrogens, Synthetic,Synthetic Estrogens,Analog, Estrogen,Analogs, Estrogen,Analogue, Estrogen,Analogues, Estrogen,Congener, Estradiol,Estrogen, Synthetic