الفهرس 
Biology of Mast Cells and Their MediatorsOnly 14 pages are availabe for public view
 |  | from | 207 |  |  |
| | | from | 207 | | |
Abstract
Mast cells have been recognized for well over 100 years. With the first histologic description of mast cells in the late 19th century was followed in the first half of the 20th century by a gradual recognition that mast cells were a source of histamine and heparin; were involved in allergic responses; and that their pathologic proliferation caused a systemic diseases.
However, it was not until the late 20th century and the identification of mast cell growth factors that mast cell research truly accelerated. Using cell lines, primary mast cell cultures, and animal models of allergic inflammation and infectious diseases, mast cells were then clearly implicated in immunity.
Allergic disease such as asthma, rhinitis, and eczema are increasing prevalence and affect up to 15% of population in Westernized countries. Among them, asthma is a chronic inflammatory disease of airways and the underlying physiological and immunological processes are not fully understood. Animal models for asthma seem to mirror the complexity seen in the human disease and duplicates many features of human asthma, including airway hyper-reactivity, and airway inflammation.
The aim of the study to describe the number, morphology, specific distribution and function of mast cells in an in-vivo model of induced asthma in guinea pigs, as compared to normal guinea pigs.
20 male guinea pigs were used. Animals were divided into 2 equal groups, a control group and a sensitized group. Ovalbumin was used for sensitization. The respiratory function of the animals assessed. At the end of experiment guinea pigs were sacrified and specimens from lung, jejunum, urinary bladder and skin were obtained. Specimens were prepared to be stained by haematoxylin and eosin stain and subjected to immunehistochemical staining and electron microscope. Quantitative analysis for data was done.
In the present study, Mast cells are present in most tissues, of the skin, the lungs, digestive tract and urinary bladder. Mast cells are found in all airways and other organs localize specifically to key tissue structures, such as the submucosal glands within asthmatic animal, irrespective of disease severity. Also fully granulated and partially degranulated mast cells are founded abundant in lung and jejunum in comparison with skin and urinary bladder.
There was significant increase in mean number of partially degranulated and fully granulated mast cells in submucosa of sensitized group compared to control group.
These findings clearly demonstrate that mast cells are not only mere effector cells during allergic reactions, but also have a complex role in the induction and regulation of immune responses. Therefore, modulation of mast cell activation could be a potential therapeutic strategy for the prevention and treatment of allergic disease.
In conclusion, mast cells play an important role in immunity. This is mainly due to their ability to produce a variety of pro-inflammatory and immune-modulatory mediators. Nevertheless, our data strongly support that the mast cell can represent an important local amplifier of antigen-dependent chronic inflammation in asthma, and that this cell can contribute significantly to multiple features of other organs as jejunum, skin and urinary bladder.
Now available to gain insight into mast cell function, these are areas that should yield to further study and then for the first time truly allow the development and application of approaches to modifying mast cell function in both health and disease.