The Contribution of cocoa additive to cigarette smoking addiction

Page 128 of 207 RIVM report 650270002
Tyramine
Conclusion
The estimated natural tyramine amount from tobacco plant is at least 2700 times
higher than the tyramine amount from added cocoa. Therefore, it is debatable
whether tyramine should be considered as an additive to tobacco. The daily potential
intake of tyramine from cigarettes (from tobacco plant and from cocoa) is higher than
tyramine intake from other sources such as chocolate or wine, and is comparable with
cheese. The plasma concentration reached after ingestion of tyramine from chocolate
or other food sources is expected to be lower or equal to tyramine after exposure
from cigarettes, assuming similar bioavailability and no loss by combustion. Also the
different route of application via smoking as compared to other sources should be
taken into account. Therefore, the systemic and the local effect of smoking related
exposure to tyramine might be a point of concern. Since nothing is known about the
pyrolysis/combustion products of tyramine, this may also be a point of concern.
PHARMACODYNAMICS
Mechanism of action
Tyramine is an indirectly acting sympathomimetic substance. It is taken up by the
neural endings where it stimulates the release of noradrenaline. Tyramine does not
affect plasma adrenaline. The effect of endogenous noradrenaline (released by
tyramine) is characterised by increased blood pressure. This increase in blood
pressure results from its myocardial positive inotrope action, mainly mediated by
cardial ß1-adrenoreceptor stimulation and is not due to vasoconstrictor effects (14).
Pulmonary system
Tyramine releases noradrenaline from the neural endings. Noradrenaline is a potent
agonist of α- and ß1-adrenoreceptors, but has little action on ß2-receptors. Since, the
smooth musculature in the respiratory system is mainly stimulated by ß2-receptors
(15), it is not expected that noradrenaline released by tyramine in the respiratory
system will lead to significant bronchial dilatation.
breathing frequency: No data available.
tidal volume: No data available.
lung compliance: No data available.
airway resistance: No data available.
Cardiovascular system
blood pressure: Tyramine (i.v. up to 20 µg/min/kg body weight for 15 min ≈ 21
mg) significantly lowered diastolic blood pressure (∆max –6.8 ± 3.1 mm Hg) and
induced a marked increase in systolic blood pressure (∆max 56.9 ± 6.8 mm Hg) in
healthy young male volunteers (26.1 ± 0.5 years, n = 12). The increased blood
pressure by tyramine is suggested to be a result of myocardial positive inotropic
action (14). Tyramine (i.v. up to 20 µg/min/kg body weight for 15 min) caused a
smaller increase in systolic blood pressure in elder healthy volunteers (61 ± 2.2
years (3 females and 3 males)) than in the healthy young volunteers; in addition it
slightly increased the diastolic blood pressure while it decreased diastolic blood