Therapeutics of experimental hypertension

782

THE

Grollman, mental

AMERICAN

HEART

JOURNAL.

Arthur, Harrison, T. R., and Williams, J. R.: Therapeutics of ExperiHyw&ension. J. Pharmacol. and Exper. Therap. 69: 76, 1940.

The effect of sodium nitrite, potassium thiocyanate, erythrol tetranitrate, Allium sativum, acetyl-p-methylcholine, sodium chloride, and renal extract on the blood pressures of hypertensive rats was investigated. The blood pressure was reduced to normal levels following the administration of renal extract. None of the so-called ‘ I depressor ” or “ hypotensive ’ ’ substances manifested an ability to reduce appreciably the blood pressure, and their clinical value is thus questionable. The administration of a relatively large dose of sodium chloride did not markedly elevate the blood pressure. AUTHORS.

Gottclenker, Indian

F., and Wachstein, Cobra

(Naia

Naia).

M.: J.

Circulatory

Pharmacol.

and

Effects of the Venom Exper.

Therap.

69:

of the

117,

1940.

In cats and rabbits the intravenous injection of a smaI1 dose of cobra venom (6 to 9p grams per kilogram) causes a long lasting rise of arterial blood pressure, occasionally preceded by an evanescent depressor effect. When the blood pressure has returned to normal the injection of a second similar dose of venom is ineffective (tachyphylaxie). Cobra venom causes vasoconstriction logic salt solution and there is no, peated administration of the venom.

in the rabbit’s ear perfused or only little, diminution of the

with physioeffect by re-

In the heart-lung preparation of the dog the injection of cobra venom (60~ grams) produces long lasting dilatation of the coronary vessels which can readily be desensitized against the venom by a previous injection of a subthreshold dose. The intravenous injection into cats of 9p grams of cobra venom per kilogram produces profound alterations in the electrocardiogram. Cobra venom causes systolic stand’still of guinea pig% heart) and of the fiber of Purkinje could be obtained in these preparations.

the auricular (dog’s heart).

strip No

(rabbit’s and tachyphylaxie

In th,e isolated frog’s heart cobra venom causes irreversible systolic contracture. During the development of the contracture the electrocardiogram shows signs of impairment of conduction, shortening of the duration of the systole and changes in the QRS complex and T wave. The absence of calcium ions in the perfusion fluid alters the response. The muscle becomes less sensitive to the venom which produces stoppage of beat without signs of systolic contracture. AUTHORS.

Gold, Harry, Kwit, Nathaniel T., and Cattell, McKeen: Digitalis Glucosides. I. Potency and Dosage of “Digitaline Administration

in Man.

J. Pharmacol.

and

Exper.

Therap.

Studies

on Purified

Nativelle” by 69: 177, 1940.

Oral

Digitalis leaf was compared with “Digitaline Nativelle”’ in a selected group of forty-nine patients, some with auricular fibrillation and others with regular sinus rhythm, in a series of experiments which extended in individual cases over periods of from twenty-four to fifty-four weeks. The

digitalis termined cussed,

results of glucosides on man

animal bio-assay methods (frog and cat method) are not transferable to man. Their potency Possible reasons for the discrepancie,s directly.

for purified must be deare not dis-