A possible antidote for methanol poisoning in mice

Acetanilide was investigated as a possible antidote against methanol poisoning in mice. The drug afforded significant protection, when administered intraperitoneally at a dosage of 100 mg/kg 30 min after the oral ingestion of methanol (1100 mg/kg). When administered after longer periods, acetanilide was of less protective value. The degree of protection seems to parallel the amount of nonmetabolized methanol remaining in the organism. The antidotal property of acetanilide is believed to be related to the inhibition of alcohol oxidation.

On the Properties of Some α-Hydroxy Phosphonates and Related Compounds

In search for effective organophosphorus esters against the larva of the cotton leaf worm (Prodenia litura F), some α-hydroxy phosphonic acid dimethyl esters and related compounds have been synthesized. The effect of substitution on the antiesterase activity and toxicity towards Prodenia larvae has been investigated.

The infra-red spectra of the prepared phosphorus esters are discussed.

Urinary schistosomiasis treated with sodium antimony tartrate--a quantitative evaluation

Seventeen Egyptian male farm-workers aged 8 to 27 years infected with Schistosoma haematobium were given twice-weekly intravenous injections of sodium antimony tartrate in a dose of 0.5 g. (30 mg.) per 15 kg. body weight for 12 injections. Bell's egg-count technique was used to evaluate results on 24-hour urine collections before and at 1, 4, 8, and 12 weeks after treatment. Patients were considered to be cured only when there were no eggs in the urine when examined by the filtration-staining, miracidial-hatching, and 24-hour urinesediment examination methods.At the final follow-up 14 out of 17 patients were found not to be passing eggs in the urine-an 82% cure rate. The mean reduction in egg output in the remaining three patients was 99%. These results are superior to any reported for other antimony drugs.

On the fate of methanol and ethanol in the adult larva of the cotton leaf worm (Prodenia litura F)

The metabolic fate of C14-methanol and 1-C14-ethanol in the adult larva of Prodenia litura has been investigated in vivo. Following the intersegmental injection of C14-methanol (1.2 mg/g. insect), about 70% of the radioactivity was recovered as C14O2 in the expired air, after 20 hours. Also, about one fourth of the administered dose was recovered as unchanged methanol, during the first six hours. Only a minute trace of C14-formate was found in the excreta. It is suggested that a catalase-peroxide system is involved in the oxidation of methanol. Ethanol and its metabolites were eliminated at a slower rate than methanol. After 20 hours, C14O2 - being the major C14-metabolite - accounted for 56% of the applied dose. In addition, there is at least one minor non-volatile C14-metabolite eliminated in the excreta of ethanol-treated larvae.

On the kinetics of inhibition of rat-brain acetylcholine esterase by Sevin

The inhibition of rat-brain acetylcholinesterase with Sevin was shown to be partly reversible. The rate of progression of the irreversible inhibition is extremely slow and follows the kinetics of a unimolecular reaction, with Κ=3.65 · 10-3 min-1 and t 0.5 190 minutes. The reversible inhibition of the enzyme was found to be of competitive nature. The dissociation constant of E — I (Ki) was determined —by two different methods —to be 5.7 and 7.6 · 10-6 Μ. The presence of acetylcholine protects the enzyme against the irreversible attack of Sevin. It is believed that acetylcholine esterase does not participate in the biological degradation of Sevin in the nervous tissue.

Acetanilide as a potent inhibitor of methanol metabolism in mice

The effect of acetanilide on the in vivo oxidation of methanol, ethanol, and formate in mice was investigated by using 14C-iabelled substrates and measuring the production of 14C-labelled carbon dioxide in the expired air. The intraperitoneal administration of acetanilide (100 mg/kg body weight) strongly inhibited the oxidation of methanol. When acetanilide was administered 20 minutes before the injection of methanol, degradation of the alcohol during the first 6 hours following its administration was inhibited 42–73%. Under similar conditions, the metabolism of formic acid was reduced to a much smaller extent (about 12%). On the other hand, the drug was without effect on the oxidation of ethanol. It was concluded that methanol and ethanol are metabolized in mice by two different enzymic systems. If it is assumed that methanol is oxidized in the mouse by a catalase–peroxide system, then the mechanism whereby acetanilide inhibits methanol degradation probably involves reduction of the peroxide pool, rather than inhibition of catalase. Acetanilide (100 mg/kg) partially protects mice against lethal doses of methanol, provided that the drug is given 20–60 minutes before methanol is administered.

METABOLISM OF ORGANOPHOSPHORUS INSECTICIDES: II. METABOLISM OF O,O-DIMETHYL-2,2,2-TRICHLORO-1-HYDROXYETHYL PHOSPHONATE (DIPTEREX) IN MAMMALIAN NERVOUS TISSUE AND KINETICS INVOLVED IN ITS REACTION WITH ACETYLCHOLINE ESTERASE

The metabolism of P32-labelled Dipterex in rat brain homogenates has been investigated. The presence of four metabolites, three acidic and one nonacidic, has been demonstrated. Monodemethylated Dipterex and monomethylphosphate contributed to 37% and 7% of the total metabolite output respectively. The third acidic metabolite (16%) is believed to be 2,2,2-trichloro-1-hydroxyethyl phosphonic acid. The nonacidic compound has not yet been identified. The reaction of Dipterex with acetylcholine esterase has been found to be of bimolecular nature.

METABOLISM OF ORGANOPHOSPHORUS INSECTICIDES: I. DISTRIBUTION AND METABOLISM OF DIPTEREX IN ADULT LARVA OF THE COTTON LEAF WORM (PRODENIA LITURA F.)

The distribution of P32-labelled Dipterex among different organs of the adult larva of the cotton leaf worm showed that the major radioactivity was translocated in hemolymph and gut. Dipterex was readily metabolized in vitro to give monodemethylated Dipterex which contributed to 91% of the acidic metabolites. Monomethylphosphate (about 9%) could also be identified as a metabolic product. The low toxicity of Dipterex to Prodenia larvae is probably due to preferential methyl ester cleavage.

METABOLISM OF ORGANOPHOSPHORUS INSECTICIDES: III. FATE OF THE METHYL GROUPS OF DIPTEREX IN VIVO

Direct evidence for the hydrolysis of O-methyl ester linkage(s) of Dipterex in the rat has been obtained using Dipterex in which the two methyl groups are C14-labelled. Following a single injection (i.p.) of radio-Dipterex, about 60% of the C14activity was recovered, after 24 hours, in the expired air and in the urine. C14O2and C14-formate constituted about 50% of the recovered radioactivity. The contribution of P—OCH3cleavage to the detoxification of the insecticide has been discussed. A scheme for the fate of the methyl groups has been suggested.

The effect of hydrolysis on the sugars of normal urine

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