Nicotine negative effects

A number of factors have been studied for their influence on nicotine production. Of these the negative effect of auxins, and in particular 2,4-D, on alkaloid production is worth mentioning (202-204,211,220, 225,226,229,255). In root cultures the addition of indoleacetic acid (lAA) also reduces alkaloid production (196). Light was reported to inhibit nicotine formation (50,255). In a green cell suspension, however, increased nicotine levels were found on illumination (229). Ikemeyer and Barz (243) reported that a photoautotrophic cell line of N. tabacum did not produce nicotine, whereas a heterotrophic cell line did accumulate this alkaloid. Elicitation with a preparation of the fungus Phytophthora megasperma did not affect the nicotine levels of these cell lines. Addition of organic acids to the medium resulted in increased alkaloid formation in callus cultures (up to 3.25%) (230). For a review of the various cultural factors which influence secondary metabolism, the reader is referred to Mantell and Smith (255). 

All cell membranes contain transmembrane proteins that form ion channels. These ion channels are usually selectively permeable to particular ions. Some channels, such as GABA-gated ion channels, are permeable to Cl ions and are inhibitory in nature because they make the inside of the nerve or muscle cells more negative as the Cl ions enter. Some ion channels are permeable to the cations Na and K, and an example of this type is the nicotinic acetylcholine-gated channel. Nicotinic channels have an excitatory effect when they open because Na ions enter and K ions leave through these channels. The cell becomes more positive inside and depolarizes. If the cell is a muscle cell, calcium accumulates in the cytoplasm and it contracts. We have found that all over the surface of Ascaris muscle there are GABA receptors (Martin, 1980) as well as nicotinic acetylcholine channels (Martin, 1982 Robertson and Martin, 1993). 

Cinciripini P, Wetter D, Tomlinson G, Tsoh J, De Moor C, Cinciripini L, Minna J (2004) The effects of the DRD2 polymorphism on smoking cessation and negative affect evidence for a pharmacogenetic effect on mood. Nicotine Tob Res 6 229-239 Clarke PB (1993) Nicotine dependence-mechanisms and therapeutic strategies. Biochem Soc Symp 59 83-95... 

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