The broad-spectrum antiemetic effects ETI-385 result from stimulation of 5-HT1A and 5-HT1D receptors.

In the present study, we describe how a nonstoichiometric ratio of the isomers of 8-hydroxy-2-(di-n-propylamino)tetralin (DPAT) produce a broad-spectrum of antiemetic effects in cats and shrews. Determination of the receptor profile of the isomers and testing them separately in cats revealed superior antiemetic effects but severe defensive behavior with the R isomer compared with the S isomer. Differing ratios yielded the best results with the 1:8 (R-S) ratio producing a drug more potent than DPAT and with negligible defensive behavior side effects. Studies with selective 5-HT1D ligands led to the conclusion that this site contributes antiemetic efficacy but is not related to defensive behavior, which is most likely a consequence of 5-HT7 receptor activation. ETI-385 was effective in preventing emetic responses to provocative motion, drugs acting at the chemical trigger zone and cisplatin in both cats and shrews. The results support a clinical trial of this drug for antiemetic effects.

Multicenter evaluation of automated immunoturbidimetric assays for measurement of apolipoproteins A-I and B in serum and plasma.

Results of a multicenter evaluation of automated assays for measurement of apolipoproteins (apo) A-I and B with the Paramax analytical system are reported. Apo A-I and apo B response surface models were used to optimize concentrations of critical assay variables. Overall imprecision for apo A-I controls at concentrations of 1.01-1.61 g/L was 3.7-6.6%; overall imprecision for apo B controls at 1.00-1.61 g/L was 2.8-6.9%. There was no interference in apo A-I measurements. Albumin concentrations > 59 g/L resulted in a negative interference, and collection in sodium heparin caused a positive interference in apo B results. Apo A-I and apo B assays demonstrated acceptable agreement with comparative methods, although the Paramax apo B assays had a negative bias with respect to comparison methods. In 116 healthy individuals, serum apo A-I ranged from 0.97 to 2.05 g/L and serum apo B ranged from 0.51 to 1.32 g/L.

Identification of the metabolites of erythro-9-(2-hydroxy-3-nonyl)hypoxanthine from laboratory animals.

After administration of erythro-9-(2-hydroxy-3-nonyl)hypoxanthine, eight compounds were isolated from the urine of rats, dogs, and monkeys. All of the drug metabolites were modified on the nonyl side chain. The oxidatively degraded metabolites included an alcohol (9-(2,8-dihydroxy-3-nonyl)hypoxanthine), the corresponding ketone (erythro-9-(2-hydroxy-8-keto-3-nonyl)hypoxanthine), and three carboxylic acids [erythro-6-hydroxy-5-(9- hypoxanthyl ) hepanoic acid, erythro-7-hydroxy-6-(9- hypoxanthyl )octanoic acid, and erythro-8-hydroxy-7-(9- hypoxanthyl )nonanoic acid]. Glucuronide conjugates of the unchanged drug and the alcohol metabolite were also found. The alcohol, ketone, and nonanoic acid metabolites were produced by all three species. Only the rat produced the shorter chain acid derivatives and no glucuronides. The monkey excreted both glucuronides, while dogs formed one glucuronide conjugate, that of the parent drug.

Inosiplex: metabolism and excretion of the dimethylaminoisopropanol and p-acetamidobenzoic acid components in rhesus monkeys.

The principal excretion products derived from radiolabeled N,N-dimethylaminoisopropanol (Dip) and p-acetamidobenzoic acid (PAcBA) components of inosiplex (Isoprinosine) were identified and quantified in urine following single iv and oral administration of the drug in rhesus monkeys. The major metabolite derived from [3H] PAcBA was identified as PAcBA-O-acylglucuronide by 1) positive naphthorescorcinol reaction for glucuronic acid and 2) hydrolysis of the metabolite to PAcBA and glucuronic acid, using either dilute base (but not acid) or beta-glucuronidase. This metabolite accounted for 50% of the administered dose in orally dosed animals and 31% in iv dosed animals. A minor metabolite, which constituted approximately 5% of the excreted 3H from either iv or orally dosed animals, was identified as the hippuric acid conjugate of PAcBA by co-chromatography with a commercial standard. A single metabolite derived from [14C]Dip was identified as Dip-N-oxide by co-chromatography with synthetic material in several chromatographic systems; this metabolite accounted for 17 to 18% of the administered 14C in either the iv or orally dosed animals.

Radioimmunoassay of the immunomodulator erythro-9-(2-hydroxy-3-nonyl)-hypoxanthine in human serum and urine.

A radioimmunoassay was developed for the measurement in human serum and urine of erythro-9-(2-hydroxy-3-nonyl)-hypoxanthine. Antisera were produced in rabbits by immunization with an erythro-9-(2-hydroxy-3-nonyl)-hypoxanthine hemisuccinate-bovine serum albumin conjugate. The competitive antigen was erythro-9-(2-hydroxy-3-nonyl)-hypoxanthine labeled with carbon-14 on the purine ring. Cross-reactivities were measured against three metabolites and the naturally occurring purine bases inosine and hypoxanthine. Sensitivity of the method was 1 ng/ml in serum and 10 ng/ml in urine. Precision at clinical levels was +/- 15% in serum at 2 ng/ml and +/- 3% in urine at 200 ng/ml.