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Biomedical subjects

Y Y Wen

Publications and source records attributed to Y Y Wen.

At least 19 recordsLinked to original sources
PubMed2000

Light-independent inactivation of dengue-2 virus by carboxyfullerene C3 isomer.

Carboxyfullerene (C60) is known as a photosensitizer for virus inactivation. Its regioisomer with C3 symmetry, named the C3 isomer, could also inactivate the dengue-2 virus without light when the dose of C3 isomer was increased to 40 microM, indicating the possible involvement of a light-independent mechanism. Further analysis showed that the C3 isomer blocked viral replication at the attachment and penetration stages, suggesting that a direct interaction between the C3 isomer and the virion is required for inactivation. The C3 isomer with a bipolar structure showed better lipid interaction and dengue-2 virus suppression than D3, another isomer that contains evenly distributed hydrophilic side chains. Moreover, the C3 isomer selectively inactivated enveloped viruses (viz., dengue-2 virus and Japanese encephalitis virus) instead of nonenveloped viruses (viz., enterovirus 71 and coxsackievirus B3). Collectively, these findings support the hypothesis that C3 isomer suppression of enveloped viruses is effected through its hydrophobic interaction with the viral lipid envelope. Our report, which demonstrates the light-dependent and -independent mechanisms of C60 on viral inactivation, will aid in the development of novel anti-viral agents for use against enveloped viruses.

Animals↗
PubMed1999

Studies on age-related changes in vascular smooth muscle and their Ca2+ mechanisms.

1. Increases in cell proliferation and DNA synthesis were observed in vascular smooth muscle cells (VSMC) from old rats. These effects were significantly enhanced by noradrenaline but were inhibited by nifedipine. 2. Ginsenosides, traditional Chinese drugs, inhibited the proliferation and DNA synthesis in VSMC from old rats. Cytosolic and nuclear Ca2+ levels, as well as calmodulin activity, were clearly higher in old rats compared with young rats. 3. Both Ca2+ and calmodulin levels rose abruptly in the late G1 phase in the VSMC cell cycle in old rats. 4. The increase in inositol phosphate levels stimulated by phenylephrine in VSMC was greater in old than in young rats. 5. The platelet-derived growth factor (PDGF) gene was overexpressed in old rats. The results indicate that vascular ageing is related to enhanced proliferation of VSMC. Abnormal Ca2+ homeostasis as well as overexpression of the PDGF gene may be responsible. 6. Nifedipine and ginsenosides may inhibit VSMC proliferation with age.

Aging↗
PubMed1998

[Changes of activities of MLCK and dephosphatase in different arterial vessels from hypertensive rats].

The changes of activities of myosin light chain kinase (MLCK) and Ca2+/CaM-PP in different arterial vessels from hypertensive and normotensive rats were studied. The results were as follows. The MLCK activity of different arteries of spontaneous hypertensive rats (SHR) was different with the order of aorta (A) >> caudal artery (CA) >> mesenteric artery (MA), while in WKY rats the order of activity among different arteries is A << CA and MA and MA Ca2+/CaM-PP is obviously higher than in SHR. In renal hypertensive rats the activities of Ca2+/CaM-PP in different arteries are not quite different from those of the Wistar rats. The above results suggest that higher activities of MLCK or/and lower activity might be related to vasocontraction and hypertension.

Animals↗
PubMed1993

[Further studies on the depressor effect of erythrocytic antihypertensive factor].

We previously demonstrated the presence of a long-acting antihypertensive factor (AHF) in the erythrocytes of essential hypertensive subjects (EHS). The present investigation demonstrates further that the AHF is also capable of producing a rapid and transient blood pressure lowering effect in stroke prone spontaneously hypertensive rats (from 26.8 +/- 1.7 to 20.1 +/- 1.5 kPa by 10-30 s, P < 0.001). An even more stronger antihypertensive effect could be found if the AHF prepared from normal subjects or rats was used. We also found that some hypertensive factor was present in EHS plasma, but not in normal subjects. The results of the present paper suggest that AHF deficiency and higher level of pressor substance may play an important role in the development of essential hypertension.

Animals↗
PubMed1991

[Effects of antihypertensive factor from erythrocytes of essential hypertensive subjects on blood pressure in rats].

The effects of antihypertensive factor (AHF) from erythrocytes of essential hypertensive human subjects on the systolic blood pressure (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive rats (SHR), renal hypertensive rats (RHR), Wistar-Kyoto rats (WKY) and Wistar rats were examined. Single intraperitoneal injection of AHF (1.6 mg/kg body weight) resulted in a significant decrease in SBP of SHR and RHR. At 10 min postinjection, AHF lowered the SBP in SHR by 34.0 mmHg. SBP recovered to the original level at 3 h. The maximal decrease of SBP in RHR by 92.5 mmHg was at 24h postadministration and the SBP did not recover until the 9th day. When AHF was administered via femoral vein (0.8 mg/kg body weight), the maximal decrease values of the SBP and the DBP were 42.8 and 48.2 mmHg in SHR at 12 min and 38.3 and 42.5 mmHg in RHR at 25 min postinjection respectively. The DBP in Wistar rats decreased considerably (from 96.7 +/- 12.9 to 83.3 +/- 11.7 mmHg) at 5 min postadministration of AHF, but no effect on DBP in WKY rats was observed. The depressor effect of AHF on SBP in RHR was dose-dependent. AHF could also antagonize the pressor effect of norepinephrine in Wistar rats.

Aged↗
PubMed1991

[Effect of antihypertensive factor on Ca2+ influx in arterial smooth muscle from normotensive and spontaneously hypertensive rats].

Aorta segments (A) and mesenteric arteries (MA) from stroke prone spontaneously hypertensive rats (SHRsp) and control Wistar Kyoto rats (WKY) were used in the present study to assess the effect of AHF on Ca2+ influx in vascular smooth muscle (VSM). The results indicated that Ca2+ influx in VSM of SHRsp was much higher than that of WKY rats (P less than 0.05). AHF at 10(-7), 10(-6) and 10(-5) g/ml can significantly inhibit Ca2+ influx in a dose-dependent manner in VSM of both A and MA (P less than 0.05 and less than 0.01). The suppression effect of AHF on Ca2+ influx and the concentration-dependent relationship were more obvious in MA than in A. The Ca2+ influx in VSM of WKY rats was unaffected by administration of AHF.

Animals↗
PubMed1991

[The depressor effect of antihypertensive factor from rat erythrocytes].

This study observed the depressor effects of erythrocyte antihypertensive factor (AHF) from spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) rats on SHR, renal hypertensive rats (RHR) and their control animals. Blood pressure (BP) tests were carried out in two parts. Chronic experiment: Six-month-old male rats weighing 200-300 g were divided into six groups: (1) Stroke prone SHR (SHRsp, n = 5); (2) WKY (n = 4); (3) RHR (n = 4); (4) Wistar (n = 4). The rats in each group were given intraperitoneal injections of AHF (10 mg/100 g BW) once. The rats in groups (5) and (6) were injected with normal saline as control. BP was measured just prior to injection and at 0.5, 1, 3, 6, 24 h and 24 h intervals thereafter. BP in SHRsp dropped (from 180.0 +/- 11.5 to 145.0 +/- 12.6, P less than 0.05). Within 24 h there was a further reduction, and the average value of the fall was 65 mmHg (P less than 0.01). BP remained significantly depressed for 4 days and did not recover until the seventh day. In contrast to the effect of this extract on SHR, the BP in WKY rats did not appear to be affected. Normal saline injected intraperitoneally did not lower BP in either SHRsp or WKY rats. BP in RHR rats showed a profound decrease within 3 h, with the average value for the drop being 56 mmHg (P less than 0.001). BP recovered to normal at 6 h. Acute group: Three SHRsp rats with BP 180.0 +/- 5.8 mmHg and weighing 231.0 +/- 11.2 g were anesthetized with sodium pentobarbital. AHF was injected into the femoral vein (0.35 mg/100 g BW). The results showed that the BP markedly decreased after administration of the extract, and the average value for the drop was 35 mmHg (P less than 0.05). The BP did not show any obvious change after injection of WKY rat extract.

Animals↗
PubMed1991

Effects of antihypertensive factor from erythrocyte of spontaneously hypertensive rats on the blood pressure and Ca2+ influx of arterial smooth muscle in rats.

The effects of a partially purified antihypertensive factor (AHF) from erythrocytes of spontaneously hypertensive rats (SHR) on the blood pressure (BP) and Ca2+ influx of vascular smooth muscle (VSM) in rats were studied. The results indicated that AHF could produce a marked prolonged depressor effect and significantly inhibit the Ca2+ influx dose-dependently on both SHR and renal hypertensive rat (RHR) either in acute or in chronic experiments, but not on normotensive rats. It suggested that the inhibition of Ca2+ influx might be one of the important mechanisms for AHF as an endogenous depressor substance.

Animals↗
PubMed1989

Effect of ligustrazine on Ca2+ uptake by inside-out red cell membrane vesicles from renal hypertensive rats.

The effect of ligustrazine (Lig) on blood pressure and Ca2+ uptake by inside-out red cell membrane vesicles (IOV) was investigated in renal hypertensive rats (RHR). After oral administration of Lig (30 mg/kg body weight/day) for 10 days, the blood pressure of RHR was not significantly changed (before vs after experiment: 147.50 +/- 2.50 vs 150.00 +/- 13.42 mmHg). The active Ca2+ uptake rate of IOVs from RHR was 5.03 +/- 1.15 nmol/ng IOV protein/min, and this was lower than that of IOVs from normotensive Wistar rats (8.95 +/- 1.08 nmol/ng IOV protein/min, P less than 0.01). In RHR, no change in IOV Ca2+ uptake capacity was observed after administration of Lig in vivo. Experiments in vitro showed that Lig markedly reduced Ca2+ uptake by IOVs from both RHR and control rats. The results indicate that the active Ca2+ transport capacity of red cell membranes is decreased in RHR and not significantly affected by oral administration of Lig; this drug, however, exerts an inhibitory effect on the transport process in vitro.

Animals↗
PubMed1983

Further investigation on the hypothesis of meridian-cortex-viscera interrelationship.

The hypothesis of Meridian-Cortex-Viscera Interrelationship maintains: 1. Meridian channel system is an independent system connected with the nerves to the cortex; 2. It acts through the nerves; 3. The nervous action is realized by humoral agents. This article gives preliminary-experimental supports for the above criteria.

Acupuncture Therapy↗