The effect of psychological stress procedures on the prothrombin time of rats.

ARIOUS WORKERS have teported experiniemstal amid clinical ohset-s-atiomss which suggested that psychological stress might affect the blood coagulation system. As early as 1771 William Hesi-somi msoted hypercoagulability of the blood follosvcd hemorrhage. In 1903 Vosburgh amid Richards29 observed misom e iapid (‘0agulatioms accompanied ami imicrease ins the blood sugar of dogs receis-imsg adtemialins. Its vieiv of the relevamsec of chamsges ims coagulability from adremsalims to Camsmsomi’s ivork ois bodily changes durimig pain amid emotiomsal excitemenit, the latter conducted several studies amid found that imi deccrebratc cats adrenalin in suitable doses considerably reduced the clotting time, ivhilc larger doses usually produced an iiscreasc its the blood coagulat-ioms time follow-cd in sonic cases by a t-eduction. Paims evoked by stimulatiomi of the splanchnic nerve, and emotionsal reactiomss ivere also followed by a shortemsitsg of the blood coagulatiomi tinse.t3 Mon-c recenst reports by Cole5 on rats exposed to sound, by Ungar28 ois guinea pigs traumsiatized in a drum, and by Morcautl omi frogs receiving electrical itijury shoss-ed deem-ease in the coagulatiomi time of blood. Clinical reports have revealed ant alterations of the blood coagulation system due to the stress of surgery amid the emotions of fear amid anxiety. A shortened clotting time during anxiety, fear, hostility, and svhile discussing stressful topics was foutsd by Schneider2021 amid Me’6 Kastt5, studying psychotic patients receivimig electroshock therapy (ECT), foumid that subjects receiving ECT at appointed times and subjects anticipatitig ECT showed a marked shortening in blood clotting time, svhile subjects receivitsg ECT without previous warning showed no chamige. Clinical reports oms the use of ACTH and cortisone suggest adrenocortical involvement its the etiology of altem-ed blood coagulatioms. Cosgriff6, Smith23, and Garrett9 have reported hypercoagulability of the blood and thromboembolic disease following the admimsistratiomi of these hormoiscs. McGraw suggests that ACTH tends to delay coagulation ansd that patients temsd to develop thrombosis when the therapy is stopped. Reconciliatioms of these opposing views as to the effect of ACTH oms blood coagulatioms is probably foumsd in Smith’s statememit, “The alterationis follow-insg these lsormssorsal agents appear to be its part, a functiomi of both the initial level of adrensal cortical activity and the integrity of the coagulat.ion mechamsism itself, svhich existed prior to the hormonal administration”.24 The most gemseral fimidinig in tlsc experimeustal amsd climsical repom-ts has beets shortening of blood coagulation time after a variety of psychological stresses. Ins contrast to this, results obtaimsed mi this laboratory svith certains sevet-e physical aisd chemical stress agensts (frostbite, 10 per censt sodiumsi chloride imitraperi-