Blood Cells - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 103

Table 3.17. R: IgE Fc receptor;

gmCSF: granulocyte-monocyte colony-stimulating factor; IL: interleukin; LT: leukotriene; PG:
prostaglandin; TNF: tumor-n ecrosis factor).

Skin mastocyte receptors and products (Source: [ 196 ]; Fc

Products Receptors

Histamine Fc R1/2

Heparin H 2 ,H 4

Tryptase, chymase PAR 2

Carboxypeptidase-A C 5 a R

Cathepsin-G
IL1 β ,IL5,IL6,IL8,IL13

TNF α

gmCSF
Proopiomelanocortin
Substance-P
PGd2, LTc4
Endothelin-1
Neurotrophins

Table 3.18. Interactions between mastocytes and the nervous system (Sources: [ 197 ]). Mas-
tocytes are associated with nerves in the skin and blood vessels in the brain, especially in
meninges. Mastocytes abound around the pituitary gland, where they can control the hypothalamo-
pituitary-adrenal axis. Mastocyte regulators include not only pathogens (mainly parasites and
bacteria), adhesion molecules, extracellular matrix proteins, nitric oxide, and cytokines, but
also neurotransmitters and neurotrophins. Substance-P released from nerve endings promotes
mastocyte-dependent granulocyte infiltration. Hypothalamic mastocytes localize close to nerve
endings that contain corticotropin-releasing hormone. This hormone is released not only by
hypothalamus, but also dorsal root ganglia. It not only activates skin mastocytes but also acts
on endothelial cells. Mastocyte proliferation can be triggered by nerve growth factor released
from leukocytes and nerve endings. Neuropeptides released from nerves can induce liberation of
chymase and production of E-selectin in adjacent microvascular endothelia similarly to substance-
P release from axons with subsequent priming of cytokine-mediated interaction between mast and
endothelial cells. However, calcitonin gene-related peptide reduces antigen-presenting capability
of mastocytes by causing degranulation and release of IL10 and TNF α . Endothelin-1 is a major

activator that causes masto cyte degranulation.

Mastocyte Nerve

Histamine Substance-P

Serotonin Endothelin-1

Peptidases Urocortin

TNF α Neurotensin

IL1/6 Nerve growth factor

Corticotropin-releasing factor

proteolysis, angiogenesis, and nerve rearrangement, is impaired in the absence
of mastocytes. Mastocytes actually participate in tissue repair and remodeling.
Mastocytes are associated with sensory nerves. Mastocyte clusters can be innervated
directly (Table 3.18 ).