Francis G. Henderson

Pharmacological properties of recanescine, a new sedative alkaloid from Rauwolfia canescens Linn.

Summary A new alkaloid isolated from Rauwolfia canescens, recanescine, appears to lack the methoxyl group in the C-ll position of reserpine. Preliminary evidence indicates that this compound retains the characteristic pharmacologic activity of reserpine. Thus, the methoxyl group is not essential for the sedative and hypotensive action of reserpine. Note added in proof Since submission of this manuscript, Stoll and Hofmann have reported the isolation of a new alkaloid, canes-cine, which is probably identical with our recanescine. (Stoll, A., and Hofmann, A., J. Am, Chem. Soc, 1955, v77, 820.)

Parotoid secretions of Indonesian toads.

A preliminary study of the parotoid secretions of Bufo melanostictus and B. asper shows that a methanol extract is rich in digitalis-like bodies (bufo-dienolides) and that an acid extract contains indolethylamine derivatives.

Parotoid secretions of Bufo blombergi and B. peltocephalus.

Summary Dried parotoid secretions of B. peltocephalus and B. blombergi have been studied for presence of substances known to occur in secretions of other toads. Catechola-mines and indolethylamine derivatives were found in both samples, more in B. peltocephalus than in B. blombergi. Cholesterol was also detected in both species. The digitalis-like substances of B. peltocephalus were more potent in cats than those of B. blombergi.

Comparison of cardiac action of bufalin, cinobufotalin, and telocinobufagin with cinobufagin.

Summary The cardiac activity of bufalin, cinobufotalin, telocinobufagin and cinobufagin has been compared. They all have a digitalis-like action. In etherized cats the order of activity from high to low is telecinobufagin > bufalin > cinobufotalin = cinobufagin.

Intestinal absorption of cardiac steroids.

Summary 1. Six cardiotonic steroids—digitoxin, lanatoside E, acetyl strophanthidin, ouabain, bufalin and bovoside A—have been compared with reference to intestinal absorption in dogs with a chronic jejunal loop. 2. Because of the dominance of vomiting before electrocardiographic changes took place the median emetic dose was estimated after intravenous and intrajejunal injections in order to appraise the absorbability of each steroid from the intestine. 3. In the dog digitoxin and acetyl strophanthidin were more easily absorbed than lanatoside E and bufalin. Ouabain was least absorbed—less than 5%. Although bovoside easily crossed the intestinal membrane it produced persistent loss of appetite resulting in death.

Liver Injury Following Administration of α-and β-Longilobine.

Summary Four closely related alkaloids-longilobine, retrorsine, α- and β-longilobine -have been compared in mice by intravenous injection. There is no significant difference in their toxicity as measured by the median lethal doses. All 4 substances produce liver damage with central necrosis as the predominating lesion.

Effect of Age upon Toxicity of Methadon.

Summary In contrast with morphine, methadon does not show a higher toxicity in very young or 1-year-old rats than in young adults, following intravenous injection.

HYPOTENSIVE ACTIVITY OF 3-(N-METHYL-T-BUTYL-AMINO)-1-BROMO-3-METHYL-1-BUTYNE HYDROCHLORIDE.

Summary It has been shown that haloethynyl derivatives have a hypotensive action in animals with a minimum of ganglionic blockade. Oral administration of compound 37157 resulted in a significant fall in blood pressure in renal hypertensive rats and dogs. In the anesthetized cat, compound 37157 lowered blood pressure and only partially blocked the contraction of the electrically stimulated nictitating membrane. The anesthetized norm-otensive dog responded with a fall in blood pressure, persisting for 5 hours. Respiration and electrocardiogram were not altered. The pressor response to carotid occlusion was completely abolished. Hypotensive activity could not be elicited in decerebrate cats and dogs, indicating partial central activity. In this preparation the pressor response to levarterenol was augmented. Compound 37157 stimulated the rabbit aortic strip and produced a delayed block of the response to angiotensin amide and levarterenol. The spastic action of angiotensin amide and serotonin on isolated ileum preparations was inhibited by 37157. The isolated rabbit uterus was stimulated. In the perfused isolated rabbit heart, there was a decrease in cardiac contractility, heart rate, and coronary flow.

Potency of Cymarin and Coumingine Hydrochloride as Influenced by Environmental Temperature

Summary The susceptibility of the frogs heart to cymarin and coumingine hydrochloride increases with the rise of environmental temperature. Coumingine hydrochloride is approximately 5 times as potent at 33°C as at 13°C (bath temperature), and cymarin is more than twice as active at 33°C as at 13°C.