FE:msrstn, M . B. and PnistRe, M . (Dept. of Pharmacology, SUNti', Downstate Medical Center,Brooklyn, N.Y .) . Mechanism of cardiovascular action of tetrodotoxin ín the cat. Cirrulntiorr

Res. 23, 553, 1968 .~~HE A1E('HANISM(S) underlying tetrodotoxin (TTX) induced cardiovascular depression in cats were studiedutilizing a variety of intact as well as chemically and surgically denervated preparations . It was found thatTTX, in doses ranging from I to 10 wg per kg i .v ., caused decreases in systolic and diastolic blood pressures,pulse pressure, heart rate, force of myocardial contraction, cardiac output, and peripheral resistance . Themaximum blood pressure reduction occurred at 5 Wg per kg while bradycardia was maximal at 2~5 l+g per kg.

Acute cardiac sympathetic denervation prevented the toxin-induced bradycardia . TTX (I-2 ~ 10-"g per ml) abolished responses to nerve stimulation in an isolated sympathetic nerve-right atrial preparationwithout affecting the spontaneous rate and force nor transmitter release by tyramine. Toxin-induced vasodilation of perfused hindlimbs was not attributed to a direct vascular smooth muscle action since it wasprevented by processes (alpha adrenergic blockade, sympathetic denervation or blockade of adrenergictransmitter release) which did not affect the activity of acetylcholine, histamine, or isoproterenol .

It was concluded that the peripheral nerve blocking effects of TTX corresponded in time and intensityto the observed circulatory depression and are entirely sufficient to account for the principal pharmacologicactions of the toxin on the cardiovascular system .

M .E. B.

GLEASON, M. N., GOSSELIN, R. E., Hooce, H. C. and $MtTFI, R. P. Clûrical ToxicoloRi~ ujC'onunercial Products (3rd Ed .) Baltimore: Williams and Wilkins, 1969 .

THIS COMPENDIUM On the treatment and identification of acute intoxications caused by commercial productsnow enters its third edition . The purpose, as stated by the compilers, is to assist the physician in dealingquickly and effectively with acute chemical poisonings, arising through misuse of commercial products .The book is divided into seven sections : First Aid and General Emergency Treatment ; Ingredients Index :Therapeutics Index; Supportive Treatment ; Trade Name Index ; General Formulations ; and Manufacturers'index. Each section is color-coded and directions for use are easily grasped.

The merits of this encyclopedic text far outweigh the minor errors, these being the toxicity ratings whichare exactly opposite those used in the Handbook ojToxicolugy and the assumption that a toxic substancecan be only ingested or inhaled . This book is an essential ingredient in the library of every physician, poisoncontrol center and hospital emergency room .

M.E.B.

MAHMWD, S. N. (Lecturer in Medicine, Faculty of Medicine, Mosul, Iraq) . Cortisone andprednisone in the treatment ofsnake bite. J, Trop . Med. Hrg. 71, 180, 1968 .

THIS ARTICLE, which is written without a reasonable degree of understanding of the functional anatomy ofsnake venom glands, a smattering of knowledge ofthe literature, little insight into the chemistry and modeof action of snake venoms, and an unawareness of the clinical variations in snake envenomation, mustcertainly go down as the most naive clinical paper on snakebite of the past decade . I am surprised that areputable journal like theJourrtalojTropicalMedicine andHygiene would publish such a paper.

No information is given on the snakes involved in the poisonings ; very little care has been exercised inthe presentation of the cases and the discussion of the clinical problem. The necessary descriptions of thesigns and symptoms of the poisonings are omitted ; no appraisal of the severity of the poisoning is noted ;no standard of therapy or control factor is given on which the author might compare his results or base hisconclusions . The author advises that in Australia (which somehow gets into the paper), people there should