Suppressive Impact of Ginsenoside-Rg2 on Catecholamine Secretion from the Rat Adrenal Medulla

This study was designed to characterize the effect of ginsenoside-Rg2 (Rg2), one of panaxatriol saponins isolated from Korean ginseng root, on the release of catecholamines (CA) in the perfused model of the rat adrenal medulla, and also to establish its mechanism of action. Rg2 (3~30 µM), administered into an adrenal vein for 90 min, depressed acetylcholine (ACh)-induced CA secretion in a dose- and time-dependent manner.Rg2 also time-dependently inhibited the CA secretion induced by 3-(m-chloro-phenyl-carbamoyl-oxy)-2-butynyltrimethyl ammonium chloride (McN-A-343), 1.1-dimethyl-4-phenyl piperazinium iodide (DMPP), and angiotensin II (Ang II). Also, during perfusion of Rg2, the CA secretion induced by high K+ , veratridine, cyclopiazonic acid, methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoro-methyl-phenyl)-pyridine-5-carboxylate (Bay-K-8644) depressed, respectively. In the simultaneous presence of Rg2 and Nω -nitro-L-arginine methyl ester hydrochloride (L-NAME), the CA secretion induced by ACh, Ang II, Bay-K-8644 and veratridine was restored nearly to the extent of their corresponding control level, respectively, compared to those of inhibitory effects of Rg2-treatment alone. Virtually, NO release in adrenal medulla following perfusion of Rg2 was significantly enhanced in comparison to the corresponding spontaneous release. Also, in the coexistence of Rg2 and fimasartan, ACh-induced CA secretion was markedly diminished compared to the inhibitory effect of fimasartantreated alone. Collectively, these results demonstrated that Rg2 suppressed the CA secretion induced by activation of cholinergic as well as angiotensinergic receptors from the perfused model of the rat adrenal gland.This Rg2-induced inhibitory effect seems to be exerted by reducing both influx of Na + and Ca 2+ through their ionic channels into the adrenomedullary cells as well as by suppressing Ca 2+ release from the cytoplasmic calcium store, at least through the elevated NO release by activation of NO synthase, which is associated to the blockade of neuronal cholinergic and AT 1 -receptors. Based on these results, the ingestion of Rg2 may be helpful to alleviate or prevent the cardiovascular diseases, via reduction of CA release in adrenal medulla and consequent decreased CA level in circulation.

Suppressive Impact of Ginsenoside-Rg2 on Catecholamine Secretion from the Rat Adrenal Medulla

This study was designed to characterize the effect of ginsenoside-Rg2 (Rg2), one of panaxatriol saponins isolated from Korean ginseng root, on the release of catecholamines (CA) in the perfused model of the rat adrenal medulla, and also to establish its mechanism of action. Rg2 (3~30 µM), administered into an adrenal vein for 90 min, depressed acetylcholine (ACh)-induced CA secretion in a dose- and time-dependent manner.Rg2 also time-dependently inhibited the CA secretion induced by 3-(m-chloro-phenyl-carbamoyl-oxy)-2-butynyltrimethyl ammonium chloride (McN-A-343), 1.1-dimethyl-4-phenyl piperazinium iodide (DMPP), and angiotensin II (Ang II). Also, during perfusion of Rg2, the CA secretion induced by high K+ , veratridine, cyclopiazonic acid, methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoro-methyl-phenyl)-pyridine-5-carboxylate (Bay-K-8644) depressed, respectively. In the simultaneous presence of Rg2 and Nω -nitro-L-arginine methyl ester hydrochloride (L-NAME), the CA secretion induced by ACh, Ang II, Bay-K-8644 and veratridine was restored nearly to the extent of their corresponding control level, respectively, compared to those of inhibitory effects of Rg2-treatment alone. Virtually, NO release in adrenal medulla following perfusion of Rg2 was significantly enhanced in comparison to the corresponding spontaneous release. Also, in the coexistence of Rg2 and fimasartan, ACh-induced CA secretion was markedly diminished compared to the inhibitory effect of fimasartantreated alone. Collectively, these results demonstrated that Rg2 suppressed the CA secretion induced by activation of cholinergic as well as angiotensinergic receptors from the perfused model of the rat adrenal gland.This Rg2-induced inhibitory effect seems to be exerted by reducing both influx of Na + and Ca 2+ through their ionic channels into the adrenomedullary cells as well as by suppressing Ca 2+ release from the cytoplasmic calcium store, at least through the elevated NO release by activation of NO synthase, which is associated to the blockade of neuronal cholinergic and AT 1 -receptors. Based on these results, the ingestion of Rg2 may be helpful to alleviate or prevent the cardiovascular diseases, via reduction of CA release in adrenal medulla and consequent decreased CA level in circulation.

Corrigendum to: Gintonin facilitates catecholamine secretion from the perfused adrenal medulla

The original version of this article contained misspelled name of authors. The name of Seung-Yeol Na is replaced with Seung-Yeol Nah. The name of Mi-Sung Choi is replaced with Mee-Sung Choi.

Factors Related to Medication Adherence in Outpatients with Schizophrenia under More Than 5 Years of Treatment / 신경정신의학

OBJECTIVES: This study aimed to investigate the medication adherence rate and related factors in chronic schizophrenia. METHODS: A total of 65 (34 male and 31 female) outpatients with schizophrenia and with less than 5 years schizophrenia treatment were randomly selected to participate in the study survey. Medication adherence rate was evaluated by counting remaining tablets. The Korean version of Drug Attitude Inventory-10 (KDAI-10) was used to determine the subjective adherence rate. Adherence was defined as a patient taking more than 80% of their total prescribed medication. Positive KDAI-10 scores indicate good adherence. RESULTS: The rate of good adherence was 87.7%. Our analysis showed that an older age (r=0.323, p=0.009), longer duration of illness (r=0.296, p=0.017), employment (F=4.41, p=0.016), remaining married (F=5.26, p=0.008), and being supported by family members, especially spouse or siblings (F=3.02, p=0.025) were significantly associated with good adherence. Presence of symptoms such as delusion (p=0.033) and hallucination (p=0.032) were related to poor adherence. CONCLUSION: The results indicate that future study should investigate patient characteristics associated with medication adherence and analyze the clinician/patient alliance and its affect on adherence. The results also show that further studies might be useful in developing and validating measures of adherence, as well as in designing and evaluating interventions to improve adherent behaviors.

Prevalence and Factors Related to Depressive Symptoms among University Students : From the Honam District, Korea / 신경정신의학

OBJECTIVES: This study investigates the prevalence of depressive symptoms and co-variates among university students in Honam district, Korea. METHODS: One thousand seven hundred and thirty (792 male and 938 female) university students were randomly selected to participate in a survey. Subjects were administered self-report questionnaires : Beck Depression Inventory, Life Experience Survey, Satisfaction with Life Scale. RESULTS: The prevalence of depressive symptoms was 14.9% overall, and 10.8% in males, 18.3% in females. In stepwise multiple regression analysis, satisfaction with life (β=-0.405, R²=0.257, p<0.001), stress (β=0.212, R²=0.312, p<0.001), suicidal attempt (β=0.133, R²=0.349, p<0.001) and female gender (β=-0.108, R²=0.358, p<0.001) were significantly associated with depressive symptoms. Among life stress factors, worry about employment, maladaptation of major field of study, appearance and body shape, lack of time and academic achievement were significantly associated, over r=0.25 with depression in sequence (r=0.256 to r=0.321). CONCLUSION: This study showed very high prevalence of depressive symptoms among university students in Honam district, Korea. Intensive mental health promotion programs to prevent depression and early detection of depressive symptoms appear needed to improve mental health status for university students.

Gintonin facilitates catecholamine secretion from the perfused adrenal medulla

The present study was designed to investigate the characteristics of gintonin, one of components isolated from Korean Ginseng on secretion of catecholamines (CA) from the isolated perfused model of rat adrenal gland and to clarify its mechanism of action. Gintonin (1 to 30 µg/ml), perfused into an adrenal vein, markedly increased the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. The gintonin-evoked CA secretion was greatly inhibited in the presence of chlorisondamine (1 µM, an autonomic ganglionic bloker), pirenzepine (2 µM, a muscarinic M₁ receptor antagonist), Ki14625 (10 µM, an LPA₁/₃ receptor antagonist), amiloride (1 mM, an inhibitor of Na⁺/Ca²⁺ exchanger), a nicardipine (1 µM, a voltage-dependent Ca²⁺ channel blocker), TMB-8 (1 µM, an intracellular Ca²⁺ antagonist), and perfusion of Ca²⁺-free Krebs solution with 5mM EGTA (a Ca²⁺chelater), while was not affected by sodium nitroprusside (100 µM, a nitrosovasodialtor). Interestingly, LPA (0.3~3 µM, an LPA receptor agonist) also dose-dependently enhanced the CA secretion from the adrenal medulla, but this facilitatory effect of LPA was greatly inhibited in the presence of Ki 14625 (10 µM). Moreover, acetylcholine (AC)-evoked CA secretion was greatly potentiated during the perfusion of gintonin (3 µg/ml). Taken together, these results demonstrate the first evidence that gintonin increases the CA secretion from the perfused rat adrenal medulla in a dose-dependent fashion. This facilitatory effect of gintonin seems to be associated with activation of LPA- and cholinergic-receptors, which are relevant to the cytoplasmic Ca²⁺ increase by stimulation of the Ca²⁺ influx as well as by the inhibition of Ca²⁺ uptake into the cytoplasmic Ca²⁺ stores, without the increased nitric oxide (NO). Based on these results, it is thought that gintonin, one of ginseng components, can elevate the CA secretion from adrenal medulla by regulating the Ca²⁺ mobilization for exocytosis, suggesting facilitation of cardiovascular system. Also, these findings show that gintonin might be at least one of ginseng-induced hypertensive components.