Toxicological evaluation of an electrically heated cigarette. Part 2: Chemical composition of mainstream smoke.

The chemical composition of mainstream smoke from an electrically heated cigarette (EHC) and that of mainstream smoke from the University of Kentucky Reference Cigarette 1R4F was analyzed. In contrast to the 1R4F, which is a conventional, lit-end cigarette, the EHC is smoked in a microprocessor-controlled lighter with electrical heater elements. The electrical heating causes the tobacco under the heater element to burn at a low temperature during each puff.

Comparison of fresh and room-aged cigarette sidestream smoke in a subchronic inhalation study on rats.

Two experimental types of cigarette sidestream smoke (SS) were compared in a subchronic inhalation study on rats. Fresh SS (FSS) was generated continuously from the reference cigarette 2R1. Room-aged SS (RASS) was generated by aging FSS for 1.

Nicotine and cotinine accumulation in pigmented and unpigmented rat hair.

This study was performed to assess the contribution of systemic and external uptake to nicotine accumulation in hair. The systemic nicotine uptake in hair was determined in pigmented rats (Brown Norway) and albino rats (Sprague-Dawley) after subcutaneous administration of 3 doses of nicotine with osmotic minipumps [5, 10, and 20 mg/(kg x day) for 3 weeks], the highest dose also following metabolic enzyme induction. The external nicotine uptake was determined in cut hair of both strains after exposure to room-aged cigarette sidestream smoke, a surrogate for environmental tobacco smoke (nicotine concentration: 5 micrograms/liter for 1, 2, and 3 weeks).

High-performance liquid chromatographic determination of nicotine and its urinary metabolites via their 1,3-diethyl-2-thiobarbituric acid derivatives.

The 1,3-diethyl-2-thiobarbituric acid (DETBA) assay for nicotine metabolites has been improved so that it can be used to determine the concentrations of nicotine and up to 12 metabolites in the urine of humans and laboratory animals, including phase 2 metabolites. The products of beta-glucuronidase cleavage found in human urine were mainly trans-3'-hydroxycotinine, cotinine, and a small amount of nicotine. Following isolation, spectroscopic analyses showed the structure of the nicotine DETBA derivative to be the one-to-one ring-opening product of DEBTA and the cyanopyridinium salt of nicotine.

Identification of cis-3'-hydroxycotinine as a urinary nicotine metabolite.

1. cis-3'-Hydroxycotinine was detected as an S(-)-nicotine metabolite in the urine of smokers as well as in the urine of rats and hamsters dosed with nicotine. 2.