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Biomedical subjects

C A Shaw

Publications and source records attributed to C A Shaw.

6 recordsLinked to original sources

Reversible kinase and phosphatase regulation of brain amino acid receptors in postnatal development.

In a previous study [Shaw, C., Pasqualotto, B. and Lanius, R.A., Mol. Neuropharmacol., in press] we have shown that phosphorylation and dephosphorylation actions of protein kinase and alkaline phosphatase lead to decreases or increases in the number of GABAA and AMPA receptors in adult rat neocortex. Using the same in vitro cortical slice preparation, we have now examined the role of these enzymes in regulating GABAA and AMPA receptors at different stages of postnatal development. GABAA receptors were labelled with [3H]SR95531 [Shaw, C. and Scarth, B.A., Mol. Brain Res., 11 (1991) 273-282]; AMPA receptors were labelled with [3H]CNQX [Lanius, R.A. and Shaw, C., Mol. Brain Res., 15 (1992) 256-262]. At postnatal day 14, GABAA receptors showed a decrease in binding in response to alkaline phosphatase treatment as opposed to an increase in binding observed in response to protein kinase treatment. Similar effects were observed for AMPA receptors at 20 days of age. The direction of regulation following the enzyme treatments were opposite to those observed in the adult cortex for both receptor populations. These fundamental changes in the enzymatic nature of regulation for such key inhibitory and excitatory receptor populations in cortex may signal an important role for age-dependent kinases and phosphatases in the events leading to modifications in neuronal function during postnatal development.

Alkaline Phosphatase

Kinetic and dynamic interactions of oral viqualine and ethanol in man.

We have studied the interaction of viqualine, a 5-hydroxytryptamine (5-HT) uptake inhibitor, with ethanol in 16 healthy men aged 20 to 34 years. The subjects were randomly assigned to receive ethanol dosed to maintain blood alcohol concentrations of 17-22 mmol.l-1 (n = 8) or orange juice (n = 8) on each of two test days one week apart and preceded, in random order, by 3 days of viqualine 75 mg bd or placebo. Ethanol had no effect on steady-state viqualine concentrations or the inhibition of 5-HT uptake. Viqualine did not affect acetaldehyde concentrations or cause an aversive alcohol-sensitizing reaction. The deleterious effects of ethanol on word recall, manual tracking, body sway, and self-ratings of intoxication, sedation, and performance were not modified by the presence of viqualine. Within each beverage group performances and self-ratings on viqualine and placebo days were not different. The first dose of viqualine was associated with transient nausea. Viqualine and ethanol do not interact kinetically or dynamically on the variables examined in this study.

Acetaldehyde

Comparative neurologic effects of diazepam and suriclone, a cyclopyrrolone anxiolytic.

Suriclone selectively displaces benzodiazepines from their binding sites but is structurally unrelated to benzodiazepines. Neurologic effects of suriclone were compared to those of diazepam in 54 subjects in a sequential, double-blind, single dose, randomized study (placebo; diazepam 10 mg; suriclone 0.2, 0.4, 0.6, or 0.8 mg). Data were collected on-line by microcomputer. Suriclone 0.2 mg did not differ from placebo. Suriclone 0.4 mg and 0.6 mg did not differ from diazepam 10 mg. Suriclone 0.8 mg caused significantly more decrement than diazepam 10 mg (p less than 0.05) in manual tracking, force platform stability, and Heath rail walking and in total severity of symptoms. Suriclone 0.8 mg caused nausea (p = 0.02), clumsiness (p = 0.02), and loss of balance (p = 0.01) more frequently than diazepam 10 mg. Suriclone 0.8 mg produced symptoms and signs qualitatively and quantitatively different from diazepam 10 mg, such as vomiting, unusual ocular movement effects, and difficulty walking. Possibly the differences in CNS drug binding for anxiolytics are associated with clinical differences in toxicity.

Adult