Topics

Intro
Cigarette Smoke
Nicotine
Carbon Monoxide
Other Substances
Smoke and Bone
Bone Healing
Wound Healing
Osteonecrosis
Lower Back Pain
Arthritis
Dupuytrens
RSD (CRPS)
Summary
Bibliography

Nicotine

Nicotine is a toxic alkaloid which represents the addictive substance in tobacco smoke. The effect of nicotine is complex since evidence suggests that it acts simultaneously as a ganglionic depressant and stimulant. As the cigarette is smoked, and nicotine is consumed, catecholamine levels rise in the bloodstream79 80 which stimulate the heart to increase output, but also causes adrenergic vasoconstriction.18 63 111 115 Peripheral vasoconstriction results in a decrease in blood flow to the extremities with a reduction in forearm blood flow and a subsequent decrease in digital blood flow.11 90 91 The inhalation of two cigarettes was found to diminish blood flow to the hand by 29 percent.107

In addition to vasoconstriction, nicotine has a direct effect upon blood coagulation. An increase in platelet adherence results in platelet aggregation with sludging of blood in small vessels, resulting in an overall decrease in microvascular profusion.72 Nicotine also results in an increase in fibrinogen levels which increases blood viscosity and induces a state of hypercoagulation.33

Nicotine also has many endocrine effects. Elevated levels of plasma vasopressin, B-endorphin, ACTH and cortisol have been noted. With high doses of nicotine, growth hormone and prolactin levels also are increased.79 92 93

Evidence also suggests that nicotine exerts a direct effect at the cellular level, resulting in toxicity to the osteoblast, 25 30 fibroblast and macrophage.95 77 Components of tobacco smoke also have been shown to create damage to the vascular endothelium, leading to the development of atherosclerosis.58