THE MAST-CELL GRANULE 



Table XVIII 



Effect of A intraperitoneal injections of M NH^OH on the histamine 



content (\Lg.jg.) and mast-cell content of tissues of rats (4 per group) 



at various times after injection 



Table XIX 



Effect of A intraperitoneal injections of A/710 NaOH on the histamine 



content (\xg.jg.) and mast-cell content of tissues of rats (4 per group) 



at various times after injection 



However, histological examination confirmed that in addition to the 

 destruction of the mast cells there was also a gross inflammatory reaction in 

 the neighbouring tissues. There were no changes in mast cells or in the 

 histamine contents of tissues remote from the peritoneum. As with compound 

 48 80, the histamine values fell and were restored in parallel with the dis- 

 appearance and reappearance of the mast cells, but there was nothing specific 

 in the effect. While these experiments thus show that a binding between 

 histamine and heparin can occur at low p\\ (Werle, 1955; Keller, 1958), it is 

 unlikely that a specific histamine-liberator acts merely by neutralizing the 

 charge on the heparin moiety. A more complex mechanism is to be anticipated. 



Effect of water 



Of greater interest perhaps is the effect of water, without the addition of 

 any chemical liberator, in releasing tissue histamine (Hagen, 1954; Grossberg 

 and Garcia- Arocha, 1954). 



119 



