192 



The Action of Adrenin on Veins. (Preliminary Communication.) 

 By J. A. G-unn and F. B. Chavasse. 



(Communicated by Prof. Francis Gotch, F.E.S. Received December 13, 1912, — 



Read February 6, 1913.) 



(From the Pharmacological Laboratory, Oxford.) 



It would be remarkable if the vein wall were the only tissue in the body 

 to possess contractile fibres without a functionally important duty of con- 

 tracting. Very little attention, however, has been paid to physiological 

 alterations in the calibre of the veins, though such alterations may be of 

 high importance in modifying physiological and pathological conditions of 

 the circulation, and in explaining certain actions of drugs. 



The following investigation was undertaken in the hope of adding something 

 to the knowledge of the contractile power of the veins ; and, though the 

 intended scope of the inquiry has not yet been completed, results have already 

 been obtained which appear to be of sufficient importance to justify their 

 being placed on record. 



Method. 



The method employed for recording the contractions of veins was similar, 

 in essential respects, to that used by Cow* for determining the reactions of 

 surviving arteries. In our experiments the veins were obtained from freshly 

 killed sheep, and put, as soon as they could be obtained, into a Dewar flask 

 containing oxygenated Ringer's solution at 37° C, and so conveyed to the 

 laboratory. 



A large water-bath, kept, unless otherwise stated, with a variation of half a 

 degree on either side, at 36° C, held two beakers containing oxygenated 

 Ringer's solution at the same temperature. In one of these beakers the veins 

 were put until required ; in the other was put the part of the vein used 

 for each experiment. For these experiments ring preparations were made. 

 It is difficult to cut quickly and without undue manipulation of the vein a 

 ring of absolutely uniform cylindrical length ; but the rings used had a length 

 averaging 1*5 mm., which varied not more than |- mm. on either side at 

 different parts of the ring. The ling was suspended between platinum 

 hooks, the lower hook being fixed, the upper attached by a silk thread to 

 a lever, which recorded variations in the calibre of the ring upon a slowly 

 revolving drum. 



* Cow, ' Journ. Physiol.,' 1911, vol. 42, p. 125. 



