Dear Gustavo,

The mast cell in fish is thought to be the Eosinophilic Granular Cell (EGC) that are common in the gastrointestinal tract, usually submucosal location. They generally contain abundant cytoplasmic granules (presumed to contain 5-HT).  Do you mean EGC from 'CGE' ? Paneth cells are a mammalian immune cell associated with the intestinal mucosa. It is not referred to in standard fish histology texts but the rodlet cell (presumed to have immune functions) do occur in the intestinal mucosa, as well as in the kidney tubules. They possess rod-like structures (2-3) located near the apical cytoplasmic membrane. Usually standard H&E histology of the intestine can only pick up the columnar enterocytes, some resident inflammatory cells that can move across the mucosal epithelium in response to irritants/insults and the goblet cells. Special immunohistochemical staining is needed to functionally identify the specific cell types. This paper on zebrafish normal intestinal histology highlights some of these staining techniques (http://www.sciencedirect.com/science/article/pii/S0925477304002503 ).  

Cheers,

Roger

http://www.sciencedirect.com/science/article/pii/S0925477304002503

Thank you Roger Chong.

Yes, I meant Eosinophilic Granular Cell (EGC). Now I'm assuming that mast cell and EGC are the same cell (different authors use different terms). There is a more appropriate term?

I'm sending you a private message to know if I can get in touch with you via email.

Cheers,

Gustavo

Yes,mast cells and  EGC are the same cells with identical functions. In fish pathology using term EGC is preferable than mast cells. But in scientifical articales you can meet these two terms.You can observe them as in normal tissue as in time of pathological process..I advice you to find a very interesting article in journal "Fish&Shellfish Immunology 2006 Reite,O.B.,Evensen. Inflammatory cells of teleostean fish: A review focusing on mast cells/eosinophilic granule cells and rodlet cells".