1. Hypotonic solutions added to human platelet-containing plasma cause a transient decrease of absorbancy of light at 610 mmu which is followed by a gradual increase of absorbancy.2. When platelets are stored for 7 hr at 4 degrees C the absorbancy changes with variations of osmolarity and their aggregation with adenosine diphosphate (ADP) remain the same. However, the reversal of absorbancy declines during storage of platelet-containing plasma.3. Platelets are not aggregated by stearate. Platelets appear to be only slightly affected by stearate concentration higher than 0.8 mM, but oleate has no effect.4. Hypertonic solutions of NaCl and urea cause increase in absorbancy of platelet-containing human plasma. Hypertonic sucrose solutions produce no more change than isotonic solutions. Hypertonic NaCl produces permanent increases in absorbancy. In human platelet-containing plasma the increased absorbancy caused by hypertonic urea is transient and declines.5. The osmotic platelet changes occur in isolated platelets as well as in platelet-containing plasma.6. The absorbancy of frozen and thawed platelet-containing plasma is not significantly altered by hypotonic solutions but the absorbancy changes caused by hypertonic solutions are similar to that of unfrozen plasma.7. The immediate absorbancy changes caused by hypo- and by hypertonic solutions are the same at 5 degrees C and 30 degrees C and are therefore probably of a physical nature. The reversal of absorbancy and aggregation of platelets by added adenosine diphosphate have Q(10) > 1 and are therefore probably of a chemical-enzymic nature.8. Divalent cations and contact activation are not required for the osmotic platelet changes and 10(-3)M-Cu(2+) and Zn(2+) do not interfere. Inhibitors of oxidative phosphorylation, electron transfer, sodium, potassium activated adenosine triphosphatases and adenosine triphosphate do not inhibit reversal of absorbancy of platelets exposed to hypotonic solutions. Cyanide, 5 x 10(-3)M, fluoride, 1.23 x 10(-2)M, iodoacetamide, 10(-2)M, are moderately effective inhibitors. At hydrogen ion concentrations above pH 8, complete inhibition occurs.9. N-ethyl-maleimide, 10(-3)M, and mercloran inhibit completely reversal of absorbancy, indicating the necessity for sulphydryl compounds.10. Intact platelets are essential for the reversal of absorbancy after hypotonic swelling. Osmotic changes by hypotonic solutions are independent of ADP aggregation of platelets.
The application in this hospital of alternating current for electro-convulsive therapy (E.C.T.) and electronarcbsis in certain mental disturhances afforded the opportunity of investigating the effects of this form of therapy on some of the components of the hlood. Schiitz (1942) ohserved in vitro a delayed coagulation of blood following application of a weak direct current.Brecht and Kummer (1943) noted a leucocytosis immediately after electrical shock; there was no alteration of hlood sugar or protein.Spiegel-Adolf, Spiegel et al. (1945) reported that following the application of a 60 cycle current at 30 volts for 1-2 seconds there were changes in cerehrospinal fluid suggesting the hreakdown of nuclear substances. This statement, however, has since heen contradicted by M. Ii. Hack (1947). Huddleson (1946) observed haemorrhages in the central nervous system in rats following electrical shock. Trojaniello (1947) indicated that dogs subjected to electrical shock by alternating current at 120 volts for a fraction of a second, showed no changes in blood lipase and diastase, but that phosphatase aetivity decreased for about 12 hours. Delay and Soulairac (1943) observed, following E.C.T. in human subjects, a transient inerease in blood albumin, and oeeasionally a slight increase in the globulin fraetion. There was a concomitant increase of blood calcium and inorganic phosphate. Purther, hyperglycemia, leucocytosis, and a decrease in the alkali reserve were demonstrable. EXPERIMENTAL.Electrical convulsions were induced in suitable patients by alternating current (50 cycles) at 120 volts. Three to eight shocks, each of a duration of 0-1 seconds, were given. Blood samples were obtained by venepuncture before and after application of the current and mixed with one-ninth volume of 0-1 M sodium, oxalate solution. The ratio of plasma: cell volume was determined in tubes of uniform size and shape and centrifugation was carried out under identical conditions, which should ensure compai'able results, if not absolute values.
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