histamine: pathological tissues 



granules could seldom be distinguished (Fig. 28). Its histamine content was 

 295 [zg./g. 



The second dog mastocytoma arrived barely a month later from Mr. K. W. 

 Head, M.R.C.V.S., of the Royal (Dick) School of Veterinary Studies, Edinburgh. 

 This specimen was part of a recurrent tumour from the right hip region of a 

 nine-year-old male Irish Setter. A diagnosis of 'mast-cell sarcoma' was made 

 from frozen sections cut and stained within twelve hours of operation. There- 

 upon a weighed portion of the original specimen was placed in trichloracetic 

 acid. Histologically the tumour contained many cells with granules which 

 stained metachromatically with toluidine blue and brilliantly with Gomori's 

 aldehyde-fuchsin method. Its histamine content was 109 y-g.jg. Encouraged 

 by these findings we approached Messrs. Boots, Nottingham, for advice 

 regarding methods for the extraction and assay of heparin in tissues. Following 

 discussions with Mr. S. W. Stroud of their research department, it was agreed 

 that the actual assays should be carried out at Nottingham. At the suggestion 

 of Mr. Stroud we therefore sent bottles of chloroform water to each of the 

 previous recipients with the request that they include a second weighed sample 

 of tissue for heparin assay. This was fortunate since the next tumour, obtained 

 locally in Dundee, proved to be a classic case both from the standpoint of 

 histamine and of heparin in mast cells. 



'Judy', a ten-year-old female Golden Cocker Spaniel, was first seen by 

 the veterinary surgeon, Dr. J. Spreull, in November 1953, on account of a 

 swelling on the right flank which had been present for a little over a month. 

 The tumour was removed under anaesthesia and sent to Edinburgh for 

 diagnosis. On learning from Mr. K. W. Head that a mast-cell tumour had 

 been located in Dundee, I approached Dr. Spreull and requested him to let me 

 know if there should be any sign of recurrence or metastasis. 



Early in January 1954 the dog was brought back with a 3 x 2 cm. lobulated 

 swelling under the skin immediately anterior to the previous excision scar. 

 This lesion was widely excised under intravenous pentobarbitone sodium 

 anaesthesia and was found to consist of a soft vascular tumour lying in a grossly 

 oedematous subcutis. There was no excessive or prolonged bleeding during 

 the operation and the wound later healed rapidly and without the formation 

 of a haematoma: in other words there was nothing to suggest clinically the 

 presence of a powerful anticoagulant in the wound area, although a prolonged 

 clotting time has been recorded in another series of cases of this type (Bloom 

 et al, 19586). Fresh weighed samples of tissue were taken for histamine and 

 heparin assay, and several minute slices were removed aseptically from the 

 centre of the tumour and placed in Tyrode's fluid for an attempt at culture of 

 mast cells in vitro by Dr. J. D. B. MacDougall of the Department of Anatomy. 

 This was successful, and the results have been published (MacDougall and 



83 



