The Contribution of cocoa additive to cigarette smoking addiction

Page 80 of 207 RIVM report 650270002
Histamine
Hyperresponsiveness to histamine is a key feature of a variety of pathological
conditions, including bronchial asthma, food allergy, colitis ulcerosa, and topical
allergic disorders. Several mediators enhance the cellular reaction to histamine in cell
types involved in pathological and immunological histamine hyperresponsiveness
(44).
Pathological histamine levels are correlated with several disorders. Normal and
pathological plasma histamine levels vary considerably in the literature. The normal
range for human plasma histamine as 0-1.0 ng/ml. Values greater than 1 ng/ml have
to be considered as pathological (45).
Patients with B cell chronic lymphocytic leukemia (B-CLL) have decreased capacity
to mount relevant antibody responses upon immunization, and development of
hypogammaglobulinemia is part of the natural history of the disease. Plasma
histamine levels determined in B-CLL patients were 2-fold to 20-fold higher in 23
out of 31 B-CLL patients, compared to normal controls and these levels showed a
significant positive correlation to disease duration. The increased plasma histamine
levels, strongly suggests the involvement of histamine in the pathogenesis of B-CLL
immunodeficiency (46).
In one study the basal plasma histamine level and eosinophil count in the peripheral
blood in patients with a history of allergy (allergic patients) were examined and
compared with those in patients without any history of allergy (non-allergic patients).
The mean basal plasma histamine level in non-allergic patients (n = 70) and allergic
patients (n = 70) were 0.31 ± 0.27 ng/ml and 0.47 ± 0.30 ng/ml, respectively (p <
0.01). The mean eosinophil counts in non-allergic patients and allergic patients were
3.3 ± 3.0% and 5.3 ± 3.4% of total white blood cells, respectively (p < 0.01). The
patients who had asthma, atopic dermatitis or a food-induced allergy showed a high
level of basal plasma histamine compared to that in non-allergic patients. The
patients with asthma, allergic rhinitis or atopic dermatitis all demonstrated a higher
eosinophil count than non-allergic patients. In addition, the correlation between the
plasma histamine level and the eosinophil count was statistically significant (p <
0.05). It was concluded that the allergic patients had both higher basal plasma
histamine levels and eosinophil counts than non-allergic patients (p < 0.01) (47).
There was also a positive correlation between basal plasma and total blood-histamine
levels (r = 0.67, p less than 0.01) in normal and asthmatic subjects suggesting that
basophils contribute significantly to plasma histamine. The spontaneous basophil
release of histamine was greater in asthmatic (13.4 ± 2%) than in normal subjects
(6.46 ± 7%, p less than 0.005), which is consistent with the higher resting plasmahistamine
levels in the asthmatic subjects (48).
Carcinogenicity
Human
Endogenous histamine has been shown to affect growth mechanisms in experimental
mammary carcinomas via cellmembrane containing H2 receptors. Both H1 and H2
binding sites are present in human mammary glands. About 75% of malignant
carcinomas express H2 receptors. The presence of mast cells around tumour tissue
raises questions concerning the source of histamine in breast tumour tissue (49).
Animal