Vol. 41 No. 1, 2002

Compound 48/80-induced Degranulation of GnRH-like Immunoreactive Mast Cells in the Brain and Mesentery of the Gerbil

Mei-Fang Yang, Chung-Liang Chien and Kuo-Shyan Lu*

Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan 100

Mei-Fang Yang, Chung-Liang Chien and Kuo-Shyan Lu (2002) Mast cells affect the extracellular milieu through the process of degranulation. Recently, mast cells in the brain of the dove and certain mammals were found to express gonadotropin-releasing hormone (GnRH)-like immunoreactivity (IR). In the present study, we examine the expression of GnRH-like IR in brain and mesenteric mast cells, and the degranulation of mast cells at these 2 sites after administration of compound 48/80 (C48/80). The gerbil, in which numerous mast cells are found in the brain and mesentery, was used as the experimental animal model. Both brain and mesenteric mast cells in control and C48/80-treated gerbils express GnRH-like IR. Mast cell degranulation was dramatic in the mesentery after C48/80 was injected intraperitoneally. Because newly extruded GnRH-like immunoreactive granules in the brain and mesentery are compact, GnRH release can be classed as a rapid-release reaction. The degranulated mast cells were restored to their normal configuration in the brain and mesentery 12 h after C48/80 treatment. We conclude that: (1) brain and mesenteric mast cells express GnRH-like IR, and (2) GnRH is released by a rapid-release reaction after C48/80 administration.

Key words: Degranulation, Mast Cell, GnRH, Brain, Mesentery.

*Correspondence: Tel: 886-2-2397-0800 ext. 8174. Fax: 886-2-2391-5292. E-mail: kslu@ha.mc.ntu.edu.tw