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F Z Wang

Publications and source records attributed to F Z Wang.

At least 55 records · Page 3Linked to original sources
PubMed1991

[An electrophysiological analysis of pathways from lateral septum to hippocampal CA1 area in rat].

Upon stimulating the lateral septal region, a population spike could be recorded in the stratum pyramidale of hippocampal CA1 together with a recordable EPSP in the apical dendrites (stratum radiatum). After destruction of hippocampal CA3, CA4 pyramidal cells by intraventricular microinjection of kainic acid, electrical stimulation of the lateral septum could no longer evoke EPSP in the apical dendrites. This experiment suggests that the neural connection of the lateral septo-CA1 apical dendrites is mediated by the collaterals of the ipsilateral CA3 pyramidal cells. But after the destruction of CA3, CA4, electric stimulation of lateral septum could still evoke EPSP in the basal dendrites (stratum oriends). The neural connection mediating the response of the lateral septo-CA1 basal dendrites was not reported before, but the neural pathway remains to be investigated.

Animals↗
PubMed1990

Cholinergic function in cultures of mouse spinal cord neurons.

Cholinergic synapses formed in cultures of fetal mouse spinal cord (SC) and superior cervical ganglion (SCG) were studied using intracellular and extracellular stimulation and recording as well as immunohistochemical staining for choline acetyltransferase (ChAT). Dissociated SC neurons and SC explants exhibited cholinergic terminals on SCG and SC neurons as demonstrated by ChAT immunoreactivity. Intracellular recordings showed that cholinergic inputs to SCG neurons were relatively common and that these synaptic inputs were blocked by the nicotinic acetylcholine (ACh) receptor blocker, tubocurarine. A comparison of three preparations indicated that the incidence of cholinergic activity recorded in SCG neurons was significantly higher in co-cultures of SCG with spinal cord ventral horn (VH) neurons grown on a substrate of non-neuronal cells from cerebral cortex, than in co-cultures with VH alone or with SC and dorsal root ganglion cells. Consistency between cholinergic physiology and staining for ChAT-positive terminals on SCG neuronal somata was obtained in cultures of SC explants grown with dissociated SCG. Application of acetylcholine, muscarine, and/or vasoactive intestinal polypeptide (VIP) produced slow excitation of SC neurons. Fast excitatory cholinergic interactions between SC neurons were not observed. Excitatory synaptic interactions between SC neurons were augmented by ACh or muscarine, while inhibitory synaptic interactions were diminished. Both types of synaptic modulation probably were produced by a presynaptic mechanism. Acetylcholine or muscarine affected synaptic interactions between SC neurons in only one-third of the synaptic connections tested, suggesting that the incidence of presynaptically cholinoceptive SC neurons is low in dissociated cell cultures. The experimental results show that a culture system incorporating dissociated fetal mouse SC neurons or explants of SC with sympathetic ganglion neurons expresses both nicotinic and muscarinic cholinergic function.

Acetylcholine↗
PubMed1990

[The relationship between tissue type plasminogen activator therapy and ventricular late potentials in acute myocardial infarction].

We studied the relationship between thrombolysis and late potentials (LP) in 137 patients with acute myocardial infarction (AMI). Among 37 patients treated with tissue-type plasminogen activator(t-PA treated group), LP were recorded in 2 patients (5%). In contrast, among 100 conventionally treated patients (control group), LP were seen in 26 (26%, P less than 0.01). When the two groups were matched with respect to age, sex, absence of prior infarction, LVEF, number of abnormal Q waves, ECG score and CAD score, the same incidence of LP was seen, i.e. 6% of the 34 t-PA treated patients had LP as compared with 24% of the 42 conventionally treated patients (P less than 0.05). Angiographic examination following t-PA infusion revealed that the incidence of LP was 0% and 40% in patients with patent and closed infarct-related coronary artery respectively. 1 year follow-up data showed that no deaths occurred in the t-PA treated group, while in the control group. 18 deaths were recorded and 8 of them were classified as sudden death. These observations suggest that patients with AMI treated early with thrombolysis have electrically more stable ventricles due to improvement of ischemia.

Aged↗
PubMed1989

Decreased incidence of ventricular late potentials after successful thrombolytic therapy for acute myocardial infarction.

In some patients with acute myocardial infarction, low-amplitude potentials that prolong the QRS complex, termed "late potentials," can be recorded on a signal-averaged electrocardiogram. The presence of these late potentials is known to be associated with an increase in the risk of ventricular tachycardia and sudden death. Because patients with acute myocardial infarction who receive thrombolytic therapy have a reduced incidence of ventricular tachyarrhythmia and sudden death, we sought to determine whether such patients also have a decreased incidence of late potentials. We studied 106 patients less than 75 years of age who were admitted with a first myocardial infarction and in whom a signal-averaged electrocardiogram was recorded within 48 hours of admission. Within four hours of the onset of chest pain, tissue plasminogen activator (t-PA) was given to 44 patients, and 62 were treated conventionally. In the t-PA group, late potentials were recorded in 2 of 44 patients (5 percent), as compared with 14 of 62 (23 percent) in the conventionally treated group (P = 0.01). Furthermore, among the patients treated with t-PA, continued occlusion of the infarct-related artery was related to the presence of late potentials. In the t-PA group, late potentials were recorded within 24 hours of angiography in 2 of the 6 patients with an occluded infarct-related artery, as compared with none of the 38 patients with a patient infarct-related artery. Our data suggest that successful thrombolytic therapy is associated with a marked reduction in the incidence of late potentials on the signal-averaged electrocardiogram. Long-term follow-up will be required to determine whether this finding predicts a reduced incidence of subsequent ventricular tachyarrhythmia and sudden death.

Cardiac Pacing, Artificial↗
PubMed1989

Alterations of coronary vascular responses to noradrenaline, acetylcholine and isoprenaline during acute myocardial ischaemia in dogs.

1. The reactivity of coronary arteries to noradrenaline (NA), acetylcholine (ACh) and isoprenaline (Iso) during acute myocardial ischaemia was studied in anaesthetized, open-chest dogs. 2. The left anterior descending coronary artery (LAD) was cannulated and perfused via an extracorporal circuit at constant flow. Ischaemia was produced by decreasing the perfusion blood flow of the LAD to 50% (moderate ischaemia) and 27% (severe ischemia) of normal. A dose of each agent which had no significant myocardial effects was chosen. Heart rate was held constant by ventricular pacing during ACh administration. 3. Under normal conditions, the infusion of NA, ACh and Iso into the LAD produced significant decreases in coronary vascular resistance (P less than 0.01). However, under either moderate or severe ischaemic conditions intracoronary NA resulted in a marked increase in coronary vascular resistance (P less than 0.01), which was completely blocked by phentolamine, an alpha-adrenoceptor blocker; intracoronary ACh and Iso did not have a significant effect on coronary vascular resistance (P greater than 0.05). 4. These results indicate that coronary arterial responsiveness to some intrinsic vasoactive substances, such as NA and ACh, is altered during acute myocardial ischaemia. This may be important in the pathophysiology of myocardial ischaemia.

Acetylcholine↗
PubMed1989

[Effect of cardiac sympathetic nerves on changes of TXB2 and 6-keto-PGF1 alpha in venous blood of ischemic myocardium].

Experiments were performed on 54 anesthetized, open-chest dogs to observe the effect of cardiac sympathetic nerves and alpha- and beta-adrenoceptor blockades on changes of platelet function during the early phase of myocardial ischemia. It was shown that contents of TXB2 and 6-keto-PGF1 alpha after coronary occlusion were markedly increased, and the platelet count was reduced in the coronary venous blood of ischemic myocardium. It was found that the changes in parameters of platelet function after coronary occlusion were significantly relieved by topical application of lignocaine-soaked gauze pads to the ischemic area of the heart or by bilateral stellectomy for blocking impulse of afferent and efferent of cardiac sympathetic nerves, compared with changes in parameters of control group, P less than 0.01. On the other hand, changes in parameters of the control group could be restored by intravenous infusion of noradrenaline to dogs which bilateral stellectomy was performed on, but not by infusion of normal saline. Different effects of alpha- and beta-adrenoceptor blockades on the changes in aforementioned parameters were found. The changing degrees in elevation of TXB2 and 6-keto-PGF1 alpha and in decrease of platelet count were significantly relieved by intravenous infusion of yohimbine (an alpha 2-blocker), phentolamine (a nonselective alpha-blocker), and propranolol (a beta-blocker), but not by infusion of prazosin (an alpha 1-blocker). Results were compared with the control group, P less than 0.01. These results suggest that cardiac sympathetic nerves play an important role for the changes of platelet function during the early phase of myocardial ischemia and that, yohimbine and phentolamine may exert an improving effect by blocking alpha 2-receptors on the platelet membrane, and propranolol may directly contribute to stabilization of the platelet membrane.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

[Content, location and action site of enkephalins in arterial walls].

Contents of L-enkephalin (L-ENK) and M-enkephalin (M-ENK) in arteries of rabbit were measured by radioimmunoassay. Mean values of L-ENK and M-ENK (pg/mg of wet tissue) were 38.99 +/- 17.29 and 134.67 +/- 8.11 in the rabbit ear artery; 31.10 +/- 7.76 and 93.60 +/- 18.22 in the renal artery; 25.70 +/- 13.60 and 88.43 +/- 18.16 in the mesenteric artery, respectively. L-ENK in these arteries decreased significantly (P less than 0.001) after chemicosympathectomy by injection of 6-OHDA; ENK in the ear artery were reduced significantly (P less than 0.001) following the excision of the superior cervical ganglion or electrical-field stimulation, but not changed after injection of reserpine. Content of NE in the artery strip bath medium was measured by fluorimetric assay. NE in the medium was decreased significantly after administration of L-ENK or M-ENK. The results suggest that enkephalins may exist in the sympathetic nerve terminals innervating arterial walls and may be released by electrical-field stimulation. Enkephalins inhibit the contracting activity of artery strips probably by decreasing the release of NE from sympathetic nerve endings.

Animals↗
PubMed1987

Intra-hisian block associated with unusual etiologies.

One hundred and sixty-nine patients underwent electrophysiologic study for atrioventricular block. Forty-five (27%) had intra-Hisian block. Four of these 45 patients had unusual etiologies: rheumatoid arthritis, cysticercosis cellulosae, Behcet's disease, and Takayasu aorto-arteritis. Their clinical and electrophysiologic features are described in detail.

Adult↗