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E Solheim

Publications and source records attributed to E Solheim.

66 records · Page 4Linked to original sources

Metabolism of some kava pyrones in the rat.

1. The metabolism in rats of several kava pyrones from Piper methysticum Forst. was studied. The compounds were the 5,6-dihydro-alpha-pyrones, dihydrokawain, kawain and methysticin, and the alpha-pyrones, 7,8-dihyroyangonin and yangonin. 2. Approx. half the dose (400 mg/kg, p.o.) of dihydrokawain was found in the urine in 48 h. About two-thirds of this was hydroxylated metabolites (three mono- and three di-hydroxylated derivatives), of which p-hydroxydihydrokawain was the most abundant. The remaining third consisted of metabolites formed by scission of the 5,6-dihydro-alpha-pyrone ring and included hippuric acid (9--13% dose). 3. Lower amounts of urinary metabolites were excreted when kawain was given, but both hydroxylated and ring-opened products were formed. 4. Methysticin gave rise to only small amounts of two urinary metabolites formed by demethylenation of the methylenedioxyphenyl moiety. 5. Urinary metabolites of the alpha-pyrones, 7,8-dihydroxyangonin and yangonin, were formed via omicron-demethylation. No ring-opened products were detected. 6. These lipophilic kava pyrones have extremely low solubility in water, which would be expected to reduce their absorption rates and appears to be responsible for the variable and low extent of metabolism observed.

Animals↗

Studies on the metabolism of the antioxidant ethoxyquin, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline in the rat.

1. The metabolism of ethoxyquin (6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline) in rat has been investigated. Urinary metabolites were identified by combined g.l.c.-mass spectrometry. 2. The major metabolic reaction was de-ethylation which gave rise to 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline and an oxidation product, 2,2,4-trimethyl-6-quinolone. Other reactions were hydroxylation to four different hydroxylated metabolites and one dihydroxylated metabolite. A total of 95% of the dose (100 mg/kg) was accounted for.

Animals↗

Metabolites of 1,2-epoxy-3-phenoxy- and 1,2-epoxy-3-(p-nitrophenoxy)propane.

1. Rabbits and rats dosed with 1,2-epoxy-3-phenoxypropane excrete 2-hydroxy-3-phenoxypropionic acid and N-acetyl-S-(2-hydroxy-3-phenoxypropyl)-L-cysteine. 2. Rabbits and rats dosed with 1,2-epoxy-3-(p-nitrophenoxy)propane excrete 2-hydroxy-3-(p-nitrophenoxy)propionic acid, N-acetyl-S-[2-hydroxy-3-(p-nitrophenoxy/propyl)propyl]-L-cysteine and p-nitrophenol. 3. The administration of either epoxide to the rat produces a marked fall in hepatic GSH level. 4. The biliary excretion of metabolites of 1,2-epoxy-3-(p-nitrophenoxy)-propane is described.

Animals↗

Transplacental passage of ketamine after intravenous administration.

This study was designed to measure how fast and at what concentrations ketamine would enter the foeto-placental circulation, when administered intravenously to 10 healthy mothers immediately before forceps delivery, which was indicated by a delayed second stage of labour. It is shown that ketamine very rapidly passes the placenta, and that ketamine levels in cord blood exceed the levels in the maternal venous blood as early as 1 min 37 s after the injection. The ketamine levels in cord blood reach a maximum in the period 1 min 37 s to 2 min 5 s after the injection. Later they show a tendency to decline. A short-lasting, marked elevation of blood pressure was produced by the ketamine anaesthesia. Two of the newborn showed low Apgar scores at 1 min. In one of them this was probably attributable to the anaesthesia.

Adult↗

Metabolism of alkenebenzene derivatives in the rat. II. Eugenol and isoeugenol methyl ethers.

1. The metabolites of 3,4-dimethoxyallylbenzene (eugenol methyl ether) and 3,4-dimethoxypropenylbenzene (isoeugenol methyl ether) in the rat were identified and quantitatively determined by g.l.c. and g.l.c.-mass spectrometry. 2. The major metabolic reactions of 3,4-dimethoxyallylbenzene were oxidation of the allylic side chain to 2-hydroxy-3-(3,4-dimethoxyphenyl)-propionic acid, 3,4-dimethoxybenzoic acid and 3,4-dimethoxycinnamic acid, the two latter being largely excreted as their glycine conjugates. The formation of the hydroxy acid presumably involved epoxidation of the double bond and subsequent hydration to the diol whereas the formation of 3,4-dimethoxycinnamic acid and 3,4-dimethoxybenzoic acid involved migration of the double bond and the formation of cinnamoyl intermediates. Other reactions were O-demethylation to 4-hydroxy-3-methoxyallylbenzene (eugenol) and 3-hydroxy-4-methoxyallylbenzene in equal amounts, oxidation to 1-(3,4-dimethoxyphenyl)-2-propen-1-ol, hydroxylation of the benzene ring to a hydroxy-3,4-dimethoxyallylbenzene and oxidation to 3,4-dimethoxyphenylacetic acid. The formation of 1-(3,4-dihydroxyphenyl)propane was found to be carried out by the rat intestinal micro-organisms. A total of at least 63% but as much as 95% dose was accounted for. 3. The major metabolic pathway of 3,4-dimethoxypropenylbenzene was via the cinnamoyl derivatives, leading to the formation of 4-hydroxy-3-methoxycinnamic acid (ferulic acid), 3,4-dimethoxycinnamic acid and 3,4-dimethoxybenzoic acid, the two latter being excreted largely as their glycine conjugates. Other reactions were O-demethylation to 4-hydroxy-3-methoxypropenylbenzene (isoeugenol) and 3-hydroxy-4-methoxypropenylbenzene in equal amounts, and oxidation to 3,4-dimethoxyphenylacetic acid and 4-hydroxy-3-methoxyphenylacetone. Epoxidation of the side chain appeared to be a minor metabolic reaction with the propenyl derivative. 4. The biliary metabolites of 3,4-dimethoxyallylbenzene and 3,4-dimethoxypropenylbenzene were identified and most of the urinary metabolites were also found in the bile.

Animals↗

The metabolism of zingerone, a pungent principle of ginger.

1. The metabolism of 4-(4-hydroxy-3-methoxyphenyl)butan-2-one (zingerone), a pungent principle of ginger, has been investigated in rats. 2. Oral or intraperitoneal dosage (100mg/kg) of zingerone resulted in the urinary excretion of most metabolites within 24 h, mainly as glucuronide and/or sulphate conjugates. While zingerone itself accounted for roughly 50-55% of the dose, reduction to the corresponding carbinol (11-13%) also occurred. Side chain oxidation took place at all three available sites and oxidation at the 3-position, giving rise to C6-C2 metabolites, predominated. About 95-97% of the dose was accounted for. 3. Appreciable (40% in 12 h) biliary excretion occurred. Biliary studies and studies in vitro using caecal micro-organisms indicated that several O-demethylated metabolites found in the urine are of bacterial origin.

Animals↗

Gas chromatography and mass spectrometry of derivatives of amino acids. Oxazolin-5-ones of several acyl-leucines.

By the action of dicyclohexylcarbodiimide on fourteen different acyl-leucines in ethyl acetate solution, the corresponding oxazolin-5-ones were formed. The reaction was quantitative and very rapid. The oxazolin-5-ones were separated on a gas chromatograph on OV-7 and EGA columns. The mass spectra of the oxazolin-5-ones showed characteristic fragments that could be used for identification.

Acylation↗

Postoperative pain after anterior cruciate ligament reconstruction using a transligamentous approach.

Anterior cruciate ligament reconstruction by free patellar tendon graft was performed using 2 different surgical approaches to the intercondylar notch in 67 consecutive patients with chronic anterior cruciate ligament insufficiency. In the first 30 patients (Group A), the traditional medial parapatellar arthrotomy with lateral luxation of the patella was done, whereas in the last 37 patients (Group B) a transpatellar tendon approach was used. Postoperative pain was managed by analgesics and, in patients who had epidural anesthesia, by administration of bupivacaine in indwelling catheters. Generally, the analgesics and bupivacaine were given immediately on request to establish comfort at rest and to permit range of motion exercises without severe pain. Compared with those in Group A, the patients of Group B had a significantly longer period from the first dose of analgesic or bupivacaine to the second, and the total number of doses of analgesic or bupivacaine was significantly lower. In the subgroup of patients with epidural anesthesia (21 in Group A and 32 in Group B), the Group B patients required significantly less analgesics, as doses equivalent to 10 mg of morphine, compared with that of Group A.

Adolescent↗

Guided tissue regeneration and local delivery of insulinlike growth factor I by bioerodible polyorthoester membranes in rat calvarial defects.

Thirty 8-week-old male Wistar rats were randomly allocated into three groups of 10 rats each. A 5-mm defect in the left parietal bone was made in each rat. In the defects of the first group of rats, no implant was used (control group). In the second group, polyorthoester membranes were placed in the defects without active substance. In the third group, polyorthoester membranes were placed with insulinlike growth factor I. The rats were sacrificed 6 weeks postoperatively. Bone formation in the defects was quantified by computer-assisted measurements of the area of the residual defect on radiographs. Host-tissue response was evaluated by light microscopy. The area of residual bone defect was greatest in the control group, less for the defects with polyorthoester membrane without active substance, and least for the defects with polyorthoester membranes with the growth factor. During histologic evaluation, no inflammation was seen, and only traces of the polyorthoester were detected in the defects with polyorthoester membrane with or without the growth factor.

Animals↗