This book serves as a reference volume for anyone interested in nicotine and tobacco. An international team of authors contribute to this comprehensive review of current knowledge on the pharmacokinetics and metabolism of nicotine. A broad range of material on the action and uptake of nicotine and the consequences of exposure to it has been drawn together for the first time in this volume. This book should be of interest to research scientists and health professionals in pharmacology, toxicology and neurosciences.

cytochemical techniques (ICC) which provide a useful adjunct to investigations by immunoblotting. A particular advantage of a cytochemical approach to the investiga tion of mitochondrial disorders is that it allows the mosaic distribution of certain of these defects to be detected, whereas the tissue homogeniza tion involved in conventional enzyme assays or immunoblotting precludes this. A further advantage of MEA or ICC is that only small amounts of tissue are needed, which is important since many of the affected patients are infants or small children. The main aim of this communica tion is to outline ways in which these techniques can be used in the diagnosis and further investigation of mitochondrial disorders. Reference will be made not only to those situations in which MEA and ICC offer advantages over standard enzyme asays and immunoblotting but also to contexts in which the reverse applies. 4. 2 MATERIALS AND METHODS Muscle biopsies for cytochemical investigation were snap-frozen using isopentane cooled to - 150 DegreesC in liquid nitrogen. Samples were stored in heat-sealed polythene packets in the vapour phase of liquid nitrogen containers. 4. 2. 1 Microphotometric enzyme assays Frozen sections 8 Jlm thick were cut using a Reichert-J ung Frigocut cryostat microtome equipped with motor-driven cutting action to maintain maximal reproducibility of section thickness. Sections were picked up on microscope slides and air-dried for 15 min at room temperature.

This book provides for the first time a single comprehensive source of information on the analytical chemistry of nicotine and related alkaloids. The editors have brought together scientists from academia and the tobacco industry to describe the state-of-the-art of the chemistry and analytical methods for measurement of nicotine. Both the scope and detail of the book are impressive. Chapters describe the history, pharmacology and toxicology of nicotine, the biosynthesis of nicotine and other alkaloids in the tobacco plant, the general chemistry of nicotine and the analytical methodologies that have been used to measure nicotine and related alkaloids in biological specimens, in tobacco and pharmaceutical products and in tobacco smoke. There is also a comprehensive review of the chemistry and toxicology of nicotine-derived nitrosamines, an important class of tobacco carcinogens.

Nicotine is an alkaloid which is present, together with a number of minor alkaloids, in tobacco and a wide variety of other plants. The introduction of tobacco as a therapeutic agent against diverse pathologi cal and physiological conditions resulted in the widespread exposure of people to nicotine, and the subsequent recognition of the pleasurable effects of tobacco consumption. Tobacco may be used for pleasure by smoking it in pipes, cigars or cigarettes or by taking it in unsmoked form as oral and nasal tobacco snuff. Nonsmokers are exposed to nico tine through plant material and side-stream tobacco smoke. This means that in humans nicotine is always utilized in the presence of a very large variety of natural compounds or their pyrolysis products, depend ing on the route of administration. These compounds may modify the absorption, distribution, metabolism and excretion of nicotine and hence alter the duration of its pharmacological action. In recent years the use of nicotine in chewing gum and cutaneous patches has been developed as an aid to smoking cessation. The toxic properties of nicotine make it useful as an insecticide, which has led to its use in agriculture and horticulture. It has also recently been recog nized that tobacco consumption may be beneficial in the prevention of Parkinson's disease or in alleviating inflammatory bowel syndrome. The above observations have continued to stimulate research into the mode of action of this relatively simple molecule."

cytochemical techniques (ICC) which provide a useful adjunct to investigations by immunoblotting. A particular advantage of a cytochemical approach to the investiga tion of mitochondrial disorders is that it allows the mosaic distribution of certain of these defects to be detected, whereas the tissue homogeniza tion involved in conventional enzyme assays or immunoblotting precludes this. A further advantage of MEA or ICC is that only small amounts of tissue are needed, which is important since many of the affected patients are infants or small children. The main aim of this communica tion is to outline ways in which these techniques can be used in the diagnosis and further investigation of mitochondrial disorders. Reference will be made not only to those situations in which MEA and ICC offer advantages over standard enzyme asays and immunoblotting but also to contexts in which the reverse applies. 4. 2 MATERIALS AND METHODS Muscle biopsies for cytochemical investigation were snap-frozen using isopentane cooled to - 150 DegreesC in liquid nitrogen. Samples were stored in heat-sealed polythene packets in the vapour phase of liquid nitrogen containers. 4. 2. 1 Microphotometric enzyme assays Frozen sections 8 Jlm thick were cut using a Reichert-J ung Frigocut cryostat microtome equipped with motor-driven cutting action to maintain maximal reproducibility of section thickness. Sections were picked up on microscope slides and air-dried for 15 min at room temperature.