• Food Science and Biotechnology
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• v.17 no.1
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• pp.156-160
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• 2008

This study was conducted to evaluate the hypotensive properties of the extract of Chinese balloon flower (Platycodon grandiflorum)'s root. In the studies for calcium channel-blocking using Xenopus oocytes, the ethanol-extract ($26.2{\pm}5.2%$) showed higher activity than water-extract. Twenty female rats were fed 25, 35, and 45 mg/kg BW/day of the ethanol-extract for 14 days to observe the changes in blood pressures and heart pulses. Ethanol-extract decreased the systolic, diastolic, and mean blood pressures of the rats. Especially, the rats fed with 45 mg/kg BW/day of the ethanol-extract showed significant decreases in the blood pressures. These results suggested that a decrease in blood pressures was due to the extension of a blood vessel with calcium channel-blocking by ethanol-extract of Chinese balloon flower. Forty %-ethanol showed the highest efficiency for ethanol-extraction of Chinese balloon flower.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.23-32
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• 1993

Recent studies have shown that a GABAergic mechanism in the brain modulates arterial blood pressure (BP) through alterations of sympathetic activity in the brain. The purpose of the present study was to determine if this modulation is involved in the pressor response to raised intracranial pressure (ICP). The pressor response to raised ICP was abolished by pretreatment of anesthetized rabbits with intracerebroventricular (icv) muscimol (a GABA agonist) as well as with icv clonidine $(an\;{\alpha}_2-agonist)$. Raising ICP in the hypertensive state after icv yohimbine $(an\;{\alpha}_2-antagonist)$ did not cause an additional increase in the BP, whereas raising ICP in the hypertensive state following icv bicuculline (a GABA antagonist) produced a further increase. Bicuculline produced an increase of the BP which had been lowered by muscimol or by clonidine, whereas it failed to increase the hypertensive state induced by either previous yohimbine or raised ICP. Yohimbine reversed the BP which had been made low by clonidine but was incapable of raising the hypotensive state after muscimol. Yohimbine failed to increase the heightened BP due to raised ICP, whereas bicuculline-induced pressor state was further elevated by yohimbine. Muscimol, besides the bicuculline-antagonizing property, inhibited the pressor response to yohimbine, suggesting participation of a GABAergic mechanism in the pressor action of yohimbine. From these results it was inferred that there were three ways in which BP could be increased via raised ICP: inactivation of the inhibitory sympathetic activity through (1) ${\alpha}_{2}-adrenoceptors$, (2) bicuculline-sensitive GABA receptors, (3) yohimbine-sensitive, clonidine-acting GABAergic sites.