Mast Cell Degranulation Practical

by isse0477500 (student)

1. I can observe from the class results that the untreated cells (The control group) had highest percentage of cells that gave a degranulation score of 0 (53.62) when compared to cells that have been treated with 48/80 (23.68), SCG (48.08) and Salbutamol (36.48). I did predict that the control cells would have had a score higher than those treated with 48/80 but I expected the cells treated with SCG and Salbutamol to have a higher percentage of cells that gave a score of 0 compared to the control. After having done research, I found out that there are endogenous factors that also cause degranulation and treating the cells with SCG or Salbutamol would not inhibit this process that has already started (Shen, W. & Louie, S. G. 1999). Therefore after careful observation, I can clearly see that there is not much difference between the control and the cells treated with SCG or Salbutamol. The cells that gave the highest percentage for degranulation score ++ was the 48/80 treated cells (39.53) and they gave a percentage of 36.79 for partial degranulation. This was also expected since the polymer 48/80 triggers degranulation in mast cells.

2. The class results agree with my prediction to an extent as I predicted that when 48/80 and SCG were added to the cells, then there would be a higher percentage of cells with degranulation score of 0 and lower percentage of cells with degranulation score of ++ when compared with 48/80 treated cells. It did not however agree with my prediction regarding the percentage of partially degranulated cell, since the percentage the class recorded was higher than that of the non-degranulated cells. I believe this is mainly due to human error in determining which cells are degranulated and those ...

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3. The results obtained from the class is that 48/80 and SCG treated cells have a higher percentage of partially degranulated (42.36) and fully degranulated (25.62) cells compared to the cells that were treated with Salbutamol and 48/80 which gave a percentage of 40.86 and 19.65 percent respectively. Having looked at the percentage of cells with a degranulation score of 0, I can observe that Salbutamol and 48/80 treated cells have a higher percentage (39.49) compared to SCG and 48/80 treated cells (32.01). This suggests that Salbutamol has a greater effect on 48/80 stimulated degranulation.

4. Salbutamol is a selective beta2-adrenergic receptor agonist (JFC 2011), therefore its mechanism of action is that it activates adenylyl cyclase, which in turn converts cyclic ATP into cyclic AMP (cAMP). Cyclic AMP then inhibits the degranulation of mast cells (Widmaier, E. et al. 2008) (Rang, H. P. et al. 2012). AS for compound 48/80, it activated phospholipase D through heterotrimeric GTP-Binding proteins. The enzyme Phospholipase D then breaks down plasma membrane phospholipids to produce IP3 (Chahdi, A. et al. 2000). IP3 then binds to receptors that are ligand-gated Ca2+ channels. The Influx of Calcium ions then causes exocytosis of the granules (Widmaier, E. et al. 2008) (Rang, H. P. et al. 2012).

Reference:

SHEN, W. and LOUISE, S. G. (1999). Immunology for pharmacy students. Amsterdam: Harwood Academic.

Joint Formulary Committee (2011). British National Formulary. 61st edition. London: British Medical Association and Royal Pharmaceutical Society of Great Britain.

WIDMAIER, E. et al. (2008). Vander’s Human Physiology. 11th edition. New York: McGraw-Hill.

RANG, H. P. et al. (2012). Rang and Dale’s Pharmacology. 7th edition. London: Elsevier.

CHAHDI, A. et al. (2000) Compound 48/80 Activates Mast Cell Phospholipase D via Heterotrimeric GTP-Binding Proteins. The Journal of Pharmacology and Experimental Therapeutics, 292 (1), pp. 122- 130.

Ahmed Loyan Abdi Ali P10525592Page