WALTER H. SEEGERS 
499 
12. Anderson, G. F. and Barnhart, M. I. Prothrombin 
synthesis in the dog. Amer. J. Physiol., 206:929-938, 
1964. 
13. Smith, H. P., Wakner, E. D., Brinkhous, K. M., 
and Seegers, W. H. Bleeding tendency and pro- 
thrombin deficiency in biliary fistula dogs: Effect of 
feeding bile and vitamin K. J. Exp. Med., 
67:911-920, 1938. 
14. Jaques, L. B. Stress and multiple factor etiology of 
bleeding. Ann. N. Y. Acad. Sci., 115:78-96, 1964. 
15. Jaques, L. B. Anticoagulant Therapy: Pharmaco- 
logical Principles. Charles C. Thomas, Springfield, 
111., 1965. 
16. Jaques, L. B. Effects of hormones and drugs on 
hemostasis. Drugs in Relation to Blood Coagula- 
tion, Hemostasis and Thrombosis. Ill International 
Pharmacological Congress, Sao Paulo, Brazil, July 
24-30, 1966. Vol. 26, pp. 25-55, Pergamon Press, 
Oxford and New York. 
17. Lechler, E., and Penick, G. D. Blood clotting 
defect in hibernating ground squirrels (Citellus 
tridecemlineatus). Amer. J. Physiol., 205:985-988, 
DISCUSSION 
P. L. Blacks HEAR, University of Minnesota, 
Minneapolis: Dr. Seegers, could you say some 
more about stress, please? Does stress only re- 
duce the tendency to coagulate or does it in- 
crease the tendency for clotting ? 
Dr. Seegers : The stress which was produced 
in these animals produces hemorrhages. The rats 
were given Dicumarol in rather high concentra- 
tion, and then stress was introduced. The num- 
ber of rats that died were then counted. On au- 
topsy they were found to have widespread 
internal hemorrhages of all kinds. These were 
even produced if, for example, a workman who 
didn't usually work there went in to replace 
one that was customarily there. This was suffi- 
cient to disturb the animals and made enough of 
them bleed to death on that psychological stress 
alone. Sham injections of saline alone produced 
the same kind of response. In other words, these 
animals were depending on three main things 
for their hemostasis : first the blood vessel wall, 
then the platelets and the coagulability of the 
blood. If the coagulability of the blood was re- 
duced to a very low level, one could then bring on 
hemorrhage by interferring with any of the 
other two. One way of doing this is with stress. 
Morris L. Povar, Brown University, Prov- 
idence, R.I. : Dr. Leo Vroman from the Veter- 
an's Hospital in New York reports that when he 
surveys a number of different animals and sur- 
veys dogs under varying degrees of stress, that 
the tendency to clot in his dogs covers the whole 
range of the many species that he investigates. 
He didn't give the dogs any drugs. He simply 
treated them poorly, got them excited, or babied 
them to make them feel secure. Have you ob- 
served such a range in any single species and 
then compared it with a number of different 
species ? 
Dr. Seegers: I must add I'm sorry if I 
left the impression that I had been doing any 
work on the stress situation. I am delighted to 
hear you mention the work of Dr. Vroman. I 
read his works too. 
