Biomaterial Database

Bioavailability of benzo(a)pyrene deposited in the lung. Correlation with dissolution from urban air particulates and covalently bound DNA adducts. 1988

S Törnquist, and M Nicklasson, and P Söderkvist, and L Nybom, and R Toftgård

Department of Medical Nutrition, The Karolinska Institute, Huddinge University Hospital, Sweden.

Dissolution kinetics of benzo(a)pyrene (B(a)P associated with urban air particulates were investigated in vitro and related to availability of the carcinogen in the isolated, perfused, and ventilated rat lung. Calculations of bioavailability and mean dissolution time in the lung produced results in concordance with experimental data. By convolution calculation, with in vitro desorption as input function and the disposition of B(a)P dosed intratracheally to the lung in an alveolar surfactant solution as reference, hypothetical areas under B(a)P buffer concentration vs. time curves (AUC) were calculated. AUC value for 1.5 micrograms of microcrystalline (MCr) B(a)P was 16 +/- 2 pmol/ml/min (N = 6), which was identical with the corresponding experimental value of 16 +/- 5 pmol/ml/min (N = 6), from lung perfusion experiments. For B(a)P adsorbed to urban air particulates (UAP-1), predicted and experimental AUC values did amount to 7 +/- 2 (N = 5) and 10 +/- 4 (N = 5) pmol/ml/min, respectively. Absolute bioavailability was calculated by deconvolution to 87% for B(a)P in alveolar surfactant. In vitro dissolution of B(a)P from urban air particulates (UAP-1 to -4) revealed a wide variation in desorption characteristics for different particulate samples. Dissolution parameters determined in vitro were positively related to mean absorption time and mean dissolution time in the lung, using three different preparations. The precision in predictions of availability of B(a)P from in vitro desorption rates, with MCr and UAP-1 representing the greatest differences observed, supports the hypothesis that desorption is the rate-limiting step during uptake of B(a)P in the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008297	Male		Males
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D000395	Air Pollutants, Occupational	Toxic air-borne matter related to work performed They are usually produced by the specific nature of the occupation.	Occupational Air Pollutants,Pollutants, Occupational Air
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001564	Benzo(a)pyrene	A potent mutagen and carcinogen. It is a public health concern because of its possible effects on industrial workers, as an environmental pollutant, an as a component of tobacco smoke.	3,4-Benzopyrene,3,4-Benzpyrene,3,4 Benzopyrene,3,4 Benzpyrene
D001682	Biological Availability	The extent to which the active ingredient of a drug dosage form becomes available at the site of drug action or in a biological medium believed to reflect accessibility to a site of action.	Availability Equivalency,Bioavailability,Physiologic Availability,Availability, Biologic,Availability, Biological,Availability, Physiologic,Biologic Availability,Availabilities, Biologic,Availabilities, Biological,Availabilities, Physiologic,Availability Equivalencies,Bioavailabilities,Biologic Availabilities,Biological Availabilities,Equivalencies, Availability,Equivalency, Availability,Physiologic Availabilities
D001711	Biotransformation	The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.