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Description
Nicotine, an active ingredient of tobacco, is a psychoactive drug - one that affects mind and behavior. It produces only a slight high in first-time users and it does not impede daily functioning to the same extent as other drugs.
Nicotine interacts with specific receptors in brain tissue, and initiates metabolic and electrical activity in the brain. In addition, nicotine causes skeletal muscle relaxation. It also acts on cardiovascular and hormonal systems.
Few other drugs act as quickly on the central nervous system as nicotine, and no other drug is ingested in such frequent and regular doses. Nicotine travels through the bloodstream twice as quickly as mainlined heroin, reaching the brain within seven seconds of each drag of smoke. By the time the smoker stubs out the cigarette, the level of nicotine in the system has peaked. Within half an hour the level drops off slightly and nicotine craving sets in.
Nicotine has many detrimental effects on pregnant women and lactating mothers. Most babies born of women smokers are smaller than normal and they are also frequently premature. Babies sometimes suffer overt signs of nicotine addiction and withdrawal, and are often afflicted with related mental and physical impairments.
Lactating mothers excrete nicotine directly through breast milk, and pregnant women transport it through their blood supply to the fetus.
Women who smoke and nurse their babies are at risk of producing an inadequate amount of milk to support their infants' energy requirements, according to some researchers.
Prolactin is a hormone that is made in the pituitary gland in the brain. During pregnancy the pituitary gland increases the production of prolactin, which stimulates the formation of milk in the breasts.
Studies performed on laboratory rats have shown that exposure to tobacco smoke reduces prolactin levels and inhibits milk production. Studies in humans have reported that smoking decreases prolactin levels and shortens the duration of breastfeeding.
Also, it has been reported that infants of smoking mothers grow at a slower rate than infants of nonsmoking mothers. This suggests that smoking may alter the amount of milk produced in the breasts.
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