Andrew Y-C Shum

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Hypoxia/reoxygenation (H/R) causes cell injury/death. We examined the protection by drugs intervening at various stages of the injury cascade in cultured neurons and glia. Primary cultures of rat cortical neurons and mixed glia were subjected to H/R. Measurements of cell death (by lactate dehydrogenase release into the medium) and viability (by MTT(More)
The relationship between central serotonergic activities and voluntary alcohol consumption was studied in Sprague-Dawley rats, which normally have low alcohol preference. After initial screening for an evenly matched baseline alcohol preference, selective central serotonergic lesioning was induced by intracisternal injection of the serotonergic neurotoxin(More)
Within the first 2 h after adrenalectomy in rats there is a marked decrease in hypothalamic, brain stem, and hippocampal serotonin (5HT) turnover. This adrenalectomy-induced decrease in brain 5HT turnover was demonstrated in this study using four different methods. These include 1) accumulation of 5HT after monoamine oxidase inhibition with pargyline, 2)(More)
In an attempt to understand the changes of circulating neuropeptide Y (NPY) during hypoxia, the plasma level of NPY was investigated by radioimmunoassay. Exposure of rats to hypobaric hypoxia at an altitude of 18,000 ft for 4 weeks causes an increase of pulmonary pressure and an elevation of plasma NPY-like immunoreactivity (NPY-LI). However, the systemic(More)
Turnover rates, as estimated from the accumulation of the intermediates, 3,4-dihydroxyphenylalanine (DOPA) and 5-hydroxytryptophan (5-HTP) following decarboxylase inhibition, were used to investigate the relationship between central catecholaminergic and serotonergic neurons and the development of hypertension in the one-kidney, one-clip renal hypertensive(More)
Turnover rates, as estimated from the accumulation of the intermediates dihydroxyphenylalanine (DOPA) and 5-hydroxytryptophan (5-HTP) following decarboxylase inhibition, were used to investigate the relationship between central catecholaminergic and serotonergic neurons and the development of hypertension in 2-kidney, 1-clip renal hypertensive rats. Results(More)
Following bilateral adrenalectomy in adult male rats, there occurs a pattern of triphasic change in basal plasma concentration of radioimmunoassayable ACTH. Plasma ACTH is markedly elevated at 2 h, has returned down almost to normal at 20 h and is again markedly elevated 96 h after adrenalectomy. We have examined serotonin (5HT) synthesis rats in several(More)
Catecholamine and serotonin neurons in the hypothalamus regulate the secretion of corticotropin releasing factor (CRF). We considered the possibility that CRF might in turn affect the activity of these aminergic neurons. We examined the effect of intracisternal administration of synthetic CRF on the synthesis turnover rates of dopamine and serotonin in the(More)
After bilateral adrenalectomy in adult male rats a triphasic change occurs in the plasma concentration of radioimmunoassayable ACTH. Plasma ACTH is markedly elevated at 2 h, returns almost to normal at 20 h, and is again markedly elevated 92 h after adrenalectomy. We have examined brain serotonin (5HT) turnover during this period using two nonsteady state(More)
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