COMPARATIVE STUDY OF THE EFFECTS OF TETRAETHYL-AMMONIUM CHLORIDE AND VERATRUM VIRIDE ON BLOOD PRESSURE IN NORMAL AND TOXEMIC PREGNANCY

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Abstract
Humoral maintenance of toxemic hypertension as contrasted with largely neurogenic blood pressure control at term of norjnal pregnancy has been suggested by observations after autonomic blockade with tetraethylammonium chloride (TEAC). Application of this concept has been further investigated in the present study in which veratrum viride, frequently used in the treatment of toxemia, has been subjected to physiologic evaluation. Ten normal term pregnancies and 12 toxemic pregnancies were studied with blood pressure assay using intraven. TEAC and veratrum. Negligible blood pressure response to veratrum occurred at term and postpartum of normal pregnancy, whereas TEAC invariably produced marked blood pressure fall prepartum and minimal responses after delivery. In toxemia, veratrum lowered systolic and diastolic levels by 50% of the total blood pressure. TEAC admn. to the same patients reduced the blood pressure by only 10%. With postpartum recovery from toxemia the marked veratrum response disappeared. As veratrum blood pressure floors rose to levels comparable to those observed postpartum of normal pregnancy, the TEAC floors descended to the same range. Veratrum side effects (bradycardia, epigastric burning, nausea and vomiting) occurred regularly, but the magnitude of the depressor response was independent of these vagal stimulation components of the drug action. Admn. of TEAC at the height of veratrum action invariably abolished the side effects, yet the depressor action persisted. The data: (1) Demonstrate diametrically opposing blood pressure effects of TEAC and veratrum in both normal pregnancy and toxemia. (2) Eliminate vagal stimulation as the cause of the marked depressor responses to veratrum in toxemia. (3) Indicate that the blood pressure of the toxemic hypertensive is consistently sensitive to veratrum. (4) Offer clues for discussion of possible modes of mediation of veratrum depressor responses in toxemia.