Basophilic granulocytes

Type I allergic reactions are inappropriate immune responses to an allergen with preferential synthesis of immunoglobulin E (IgE), a special antibody class, which binds to mast cells and basophilic granulocytes via Fee receptors. Binding of the allergen to the cell-bound IgE initiates the rapid release of allergic mediators, most prominently histamine, and the de novo synthesis of arachidonic acid metabolites and cytokines, which are responsible for the clinical symptoms. 

Histamine, an important mediator (local signaling substance) and neurotransmitter, is mainly stored in tissue mast cells and basophilic granulocytes in the blood. It is involved in inflammatory and allergic reactions. Histamine liberators such as tissue hormones, type E immunoglobulins (see p. 300), and drugs can release it. Histamine acts via various types of receptor. Binding to Hi receptors promotes contraction of smooth muscle in the bronchia, and dilates the capillary vessels and increases their permeability. Via H2 receptors, histamine slows down the heart rate and promotes the formation of HCl in the gastric mucosa. In the brain, histamine acts as a neurotransmitter. 

Basophilic granulocytes Release of histamine and serotonine in certain immime reactions 4X10 Few hours... 

Colchicine produces a temporary leukopenia that is soon replaced by a leukocytosis, sometimes because of a striking increase in the number of basophilic granulocytes. The site of action is apparently directly on the bone marrow. Myopathy and neuropathy also have been noted with colchicine treatment, especially in patients with decreased renal function. Long-term administration of colchicine entails some risk of agranulocytosis, aplastic anemia, myopathy, and alopecia azoospermia has also been described. 

Histamine released test (HRtest)—measurement of histamine release from basophile granulocytes. HR is more complicated for daily clinical practice but may be a helpful tool in certain cases of infrequent food or drug allergy (Burks and Sampson, 1992 Burks, 2000). 

Oral exposure of rats to hexachlorobenzene results in a dose-dependent increase in the number of peripheral neutrophilic and basophilic granulocytes and monocytes and of spleen and lymph node weights. Histopathology shows increased marginal zones and follicles and extramedullary haematopoiesis in the spleen and increased numbers of high endothelial venules in mesenteric lymph nodes and popliteal lymph nodes (Vos et ah, 1979a, 1979b, 1983 Michielsen et ah, 1997). These immune effects were more obvious in Brown Norway rats than in Lewis or Wistar rats (Michielsen et... 

CC) represent the chemokines with the most restricted spectrum of action being selectively active on eosinophilic and basophilic granulocytes (Schall, 1994 Ben-Baruch et al., 1995 Bagglolini et al., 1997 Mantovani et al., 1998). Lymphotactin and fractalklne are the only proteins so far described with a C and CX3C motif, respectively (Kelner et al., 1994 Bazan et al., 1997 Pan et al., 1997). They both act on lymphoid cells (T-lymphocytes and NK cells) and fractalklne is also active on monocytes and NK cells (Kelner et al., 1994 Bianchi et al., 1996 Bazan et al., 1997 Imai et al., 1997 Pan et al., 1997). 

Helm B, Kebo D, VerceUi D, Glovsky MM, Gould H, Ishizaka K, Geha R, Ishizaka T. Blocking of passive sensitization of human mast cells and basophil granulocytes with IgE antibodies by recombinant human epsilon-chain fragment of 76 amino acids. Proc Natl Acad Sci USA 1989 86 9465-9469. 

White Blood Cells. White blood cells, or leukocytes, have varying function and morphology. Mononuclear leukocytes include lymphocyte B and T-ceUs, monocytes, and progenitor cells. Polynuclear granulocytes include neutrophils, basophils, and eosinophils. The most important groups in cell separation are lymphocytes, monocytes, and granulocytes. 

Dvorak AM The mouse basophil, a rare and rarely recognized granulocyte. Blood 2000 96 1616-1617. Voehringer D, Shinkai K, Locksley RM Type 2 immunity reflects orchestrated recruitment of cells committed to IL-4 production. Immunity 2004 20 267-277. 

Bacterial infections are associated with elevated granulocyte counts (neutrophils, basophils), often with increased numbers of immature forms (band neutrophils) seen in peripheral blood smears (left-shift). With infection, peripheral leukocyte counts may be very high, but are rarely higher than 30,000 to 40,000/mm3. Low neutrophil counts (neutropenia) after the onset of infection indicate an abnormal response and are generally associated with a poor prognosis for bacterial infection. 

Granulocytes Leukocytes with abundant granules in the cytoplasm. They are divided into three groups neutrophils, eosinophils, and basophils. [NIH]... 

Immune responses are mediated through the lymphocytes called B cells and T cells. Lymphocytes are a particular type of white blood cell. White blood cells (leukocytes) are divided into granulocytes (neutrophils, 55-70% eosinophils, 1-3% and basophils, 0.5-1%) and agranulocytes (lymphocytes [B and T cells], 20-40% and monocytes, 1-6%). There are 5000-10,000 white blood cells per milliliter of blood, compared with five million red blood cells in the same volume. 

Granular leukocytes (Granulocytes) Neutrophils Basophils Eosinophils... 

Basophils and Eosinophils. These two types of granulocyte represent only a small proportion of the circulating leukocytes. The basophil possesses receptors specific for the Fc portion of IgE molecules. It is involved in allergic reactions and can play a role in the clinical state of anaphylaxis, which is a life-threatening allergic response. Eosinophils are involved with the immune reactivity of drug allergies and with the body s immune response to parasitic infestations such as worms (see chapter 9). 

Granulocytes of diameter 9-12 pm are formed in the red bone marrow. Three types are distinguished by staining neutrophils, eosinophils, and basophils. 

---