PHYSIOLOGIC IMPORTANCE OF LYMPH 



I°59 



to egg albumin to result in an immediate and marked 

 increase in thoracic duct lymph flow with increased 

 concentrations of calcium, amino nitrogen, and 

 magnesium, and decreased concentrations of sodium 

 and potassium. They did not measure proteins. 

 Dragstedt and his colleagues (55-57, 82) reported 

 that, in the dog at least, the vasomotor symptom 

 and death occurring in anaphylactic shock are 

 brought about by the sudden discharge into the 

 circulating blood of a vasodepressor, smooth muscle- 

 stimulating substance which is apparently histamine. 

 They were able to detect this substance in blood and 

 thoracic duct lymph for brief periods of time after 

 the assaulting or shocking dose of serum, and to corre- 

 late its appearance with varying grades of severity of 

 the shock in such a way as to indicate that it had a 

 causal relationship to the shock symptoms. More 

 specific results were recently reported by Logan (127) 

 who showed that bovine globulin is a satisfactory 

 antigen for sensitizing rats when given intraperi- 

 toneally simultaneously with Bordetella pertussi 

 vaccine. Intestinal lymph of animals so sensitized 

 contained increased amounts of histamine when 

 collected 6 min after intravenous injection of the 

 shocking dose. The amount of lymph histamine was 

 roughly proportional to the degree of shock. The rate 

 of lymph flow increased 8 to 25 times during the 12 

 min immediately after administration of the shocking 

 dose and the lymph contained o to 0.02 /ig histamine 

 per ml, an amount similar to that in plasma. 



The lymphagogue action of histamine is well 

 known and can readily be demonstrated by the 

 intravenous injection of small amounts of the sub- 

 stance (95). This effect has usually been ascribed to 

 dilation and increased permeability of capillaries, 

 although the exact mechanisms involved have never 

 been clearly defined. Rusznyak et al. (189) review 

 much of the evidence and report experiments done 

 in their own laboratories by Szabo and Magyar. The 

 latter injected a dextran fraction of approximately 

 the same molecular weight as albumin simultaneously 

 with histamine and with Evans blue. In dogs, flow 

 of intestinal and hepatic lymph increased two to 

 three times and remained high; appearance of dextran 

 and dye-labeled albumin in lymph was much sooner 

 as was equilibration between plasma and lymph. The 

 authors believe they have ruled out the factor of 

 increased filtration pressure in favor of increased 

 capillary permeability. Repetition of the same experi- 

 ments in cats gave entirely negative results, i.e., no 

 increased lymph flow or accelerated equilibration. 

 The authors explain these differences as being due 



to the fact that in the dog not only the capillaries 

 and small veins but also the arterioles are dilated by 

 histamine (and only the larger visible arteries con- 

 stricted), while in the cat this constrictor effect begins 

 more peripherally in the arterioles. The authors 

 take issue with the assumption by Krogh (117) that 

 dilation of capillaries leads to increased permeability, 

 since capillaries dilate in the cat quite as much as 

 in the dog without showing increased permeability. 



Changes in blood coagulability are among the 

 important findings in the anaphylactic reaction 

 (67, 104) and result from the release of heparin from 

 the liver. The possibility that this substance may be 

 transported from the liver to the blood stream by- 

 way of the thoracic duct was first suggested by Gley 

 (87) who found that ligation of the liver lymphatics 

 prevented the incoagulability of blood following 

 peptone shock. White & Woodward (228-230) 

 showed that the incoagulability of thoracic duct lymph 

 following an anaphylacytic or peptone-induced 

 shock is due to heparin and that the main portal of 

 entry for this substance into the blood stream is via 

 the thoracic duct from the liver. The concentration of 

 heparin in lvmph in these situations was greater than 

 in arterial or hepatic venous blood and it was fre- 

 quently present only in thoracic duct lymph. When 

 heparin was given intravenouslv the concentration of 

 heparin was the same in thoracic duct lymph and in 

 plasma. Furthermore, heparin did not appear in 

 cervical or right duct lymph unless it first appeared in 

 blood. Removal of the liver prevented the appearance 

 of heparin in peptone-shocked dogs. These findings 

 confirm the liver as being the origin of heparin under 

 these circumstances. Heparin was not released into 

 thoracic duct lvmph or blood during a hemorrhage- 

 induced shock, thus ruling out hypotension as a factor 

 in the heparin release. It is suggested that the release 

 of the heparin may depend upon limited cellular 

 reactions and not upon general cellular activity. 



Traumatic Shock 



There has been considerable interest in studying the 

 participation of the lymphatic system in traumatic 

 shock. These studies have taken different forms. 

 The Hungarian workers (188) have done a consid- 

 erable amount of work in which they have measured 

 lymph flows from various areas and used the compo- 

 sition of lymph as a measure of capillary permeability. 

 There has been a recurrent interest in the presence 

 or absence in lymph of a "toxic" substance which may 

 or may not have come from the plasma. 



