Biomaterial Database

Hydrolysis, absorption and metabolism of di(2-ethylhexyl) terephthalate in the rat. 1994

E D Barber, and J A Fox, and C J Giordano

Eastman Kodak Co., Corporate Health and Environment Laboratories, Rochester, NY 14652-3615.

1. The hydrolysis of di(2-ethylhexyl) terephthalate (DEHT) and di(2-ethylhexyl) phthalate (DEHP) were studied using rat gut homogenate fractions in vitro. Both isomers were hydrolysed by the intestinal fraction; however, DEHP was hydrolysed to 2-ethylhexanol (2-EH) and mono(2-ethylhexyl) phthalate (MEHP) in about equal proportions, whereas DEHT was hydrolysed to 2-EH and terephthalic acid (TPA). The half-lives for disappearance of the diesters were determined to be 12.6 min for DEHP and 53.3 min for DEHT. 2. The absorption and metabolism of DEHT were studied by administering [hexyl-2-14C]DEHT (in corn oil) by oral gavage at a dose level of 100 mg/kg to 10 adult male Sprague-Dawley rats. Urine, faeces and expired air were collected for 144 h and analysed for the presence of radioactivity, and faeces and urine were analysed for unlabelled metabolites. 3. Radioactivity was eliminated in faeces (56.5 +/- 12.1% of dose) primarily as unchanged DEHT, small amounts of MEHT and polar metabolites; excreted in urine (31.9 +/- 10.9% of dose) principally as MEHT and metabolic products of 2-EH; and expired as 14CO2 (3.6 +/- 0.9% of dose). Less than 2% of the administered radioactivity was found in the carcass. Small amounts of 14C were found in the tissues with the highest amounts found in liver and fat. 4. Metabolites identified in urine included terephthalic acid (equivalent to 51% of dose), oxidized metabolites of 2-EH and MEHT, and glucuronic and sulphuric acid conjugates (equivalent to about 10% of dose).(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007408	Intestinal Absorption	Uptake of substances through the lining of the INTESTINES.	Absorption, Intestinal
D007413	Intestinal Mucosa	Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.	Intestinal Epithelium,Intestinal Glands,Epithelium, Intestinal,Gland, Intestinal,Glands, Intestinal,Intestinal Gland,Mucosa, Intestinal
D008297	Male		Males
D010795	Phthalic Acids	A group of compounds that has the general structure of a dicarboxylic acid-substituted benzene ring. The ortho-isomer is used in dye manufacture. (Dorland, 28th ed)	Acids, Phthalic
D010968	Plasticizers	Materials incorporated mechanically in plastics (usually PVC) to increase flexibility, workability or distensibility; due to the non-chemical inclusion, plasticizers leach out from the plastic and are found in body fluids and the general environment.	Plasticizer
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D004051	Diethylhexyl Phthalate	An ester of phthalic acid. It appears as a light-colored, odorless liquid and is used as a plasticizer for many resins and elastomers.	Dioctyl Phthalate,Bis(2-ethylhexyl)phthalate,DEHP,Di(2-ethylhexyl)phthalate,Di-2-Ethylhexylphthalate,Di 2 Ethylhexylphthalate,Phthalate, Diethylhexyl,Phthalate, Dioctyl
D004064	Digestive System	A group of organs stretching from the MOUTH to the ANUS, serving to breakdown foods, assimilate nutrients, and eliminate waste. In humans, the digestive system includes the GASTROINTESTINAL TRACT and the accessory glands (LIVER; BILIARY TRACT; PANCREAS).	Ailmentary System,Alimentary System
D005243	Feces	Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.