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Biomedical subjects

M Q Chen

Publications and source records attributed to M Q Chen.

At least 19 recordsLinked to original sources
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

[Studies on reaction and antibacterial activity of 1-aryl-4-ethoxycarbonyl-5-amino-1,2,3-triazole with several electrophilic reagents].

Upon treatment of 1-aryl-4-ethoxycarbonyl-5-amino-1,2,3-triazoles (1) with excess acetic acid, acetic anhydride, acetyl chloride, benzoyl chloride, formamide, etc., fourteen new derivatives of 1 were obtained in good yields, such as, 1-H-4-ethoxycarbonyl-5-arylamino-1,2,3-triazoles (2b-d), 1-RCO-4-ethoxycarbonyl-5-arylamino-1,2,3-triazoles (3a-d), 1-aryl-4-ethoxycarbonyl-5-acetylamino-1,2,3-triazoles (4a-d) and 1-formoyl-4-ethoxycarbonyl-5-p-nitrophenylamino-1,2,3-triazole (5a), 1-benzoyl-4-ethoxycarbonyl-5-p-nitrophenylamino-1,2,3-triazoles (5b), 1-p-chlorobenzoyl-4-ethoxycarbonyl-5-p-nitrophenylamino-1,2,3-triazoles (5c). Some of them were rearrangement products. Structures of all heterocyclic compounds were identified by elemental analyses, IR, 1HNMR and MS. Inhibiting effects of some compounds on B. substilis, E. coli, E. aerogenes and S. aureus were also screened.

Anti-Bacterial Agents↗
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↗
PubMed1990

[Alterations of the sympathetic activity, plasma catecholamine content and pulmonary surfactant in neurogenic pulmonary edema in rats].

Neurogenic pulmonary edema (NPE) was induced by microinjection of kainic acid into bilateral preoptic area (POA) of the hypothalamus in rats. Sympathetic discharge of the left adrenal branch was recorded, plasma catecholamine (CA) was assayed and the physical properties of pulmonary surfactant (PS) of the lung lavage were measured. The results showed that some physical properties of PS were changed in NPE, i.e. maximal surface tension (gamma Max) decreased, minimum surface tension (gamma Min) increased, recruitment index (RI), stability index and area of hysteresis loop (H-area) decreased. After injection of kainic acid into POA, the sympathetic discharge increased by 22.8 +/- 7.20% and 32.2 +/- 8.0% respectively at 30 and 60 min after injection and paralleled by a marked elevation of plasma catecholamine (CA). The results showed that PS activity had decreased at an early stage of NPE and the change of the plasma CA level was parallel to that of sympathetic discharge. It is suggested that generation of NPE may be related to some disorder of the autonomic nervous system at the level of hypothalamus, increase of sympathetic discharge, elevation of plasma CA level and fall of PS activity.

Animals↗
PubMed1989

The role of the nucleus tractus solitarius and the locus coeruleus in the abdominal vagal pressor response.

The central mechanism of the pressor response induced by stimulation of the central ends of abdominal vagi (SCAV) was studied in 33 anesthetized cats. The results of the experiments showed that both electro-stimulation to part of the nucleus tractus solitarius (NTS) and SCAV caused similar rises of blood pressure. The microinjection of kainic acid into the NTS (40 mmol/L, 2 microliters) evoked a prolonged rise of blood pressure but did not affect the pressor response induced by SCAV. Electro-stimulation of the locus coeruleus (LC) also elicited a pressor effect. Kainic acid at blocking dose (40 mmol/L, 2 microliters bilaterally injected into the LC induced an increase followed by a decrease in blood pressure and markedly attenuated the SCAV's pressor response. Bilateral microinjections of phentolamine (4 micrograms/2 microliters), propranolol (2 micrograms/2 microliters) or 6-hydroxydopamine (6-OHDA, 8 micrograms/2 microliters) into LC had no significant effect on the pressor response, but atropine could markedly attenuate it. These results suggest that the pressor afferents in abdominal vagi do not terminate in but pass through the NTS and the neurons in the LC play an important role in the SCAV pressor reflex. Cholinergic transmission rather than catecholaminergic transmission in the LC may be involved in this pressor response.

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↗