Search results for "Plexus"
showing 10 items of 164 documents
GABAergic inhibition of nitric oxide-mediated relaxation of guinea-pig ileum
1999
The effects of GABA receptor agonists were investigated on guinea-pig isolated ileum longitudinal muscle with intact myenteric plexus. Electrical field stimulation (1 Hz, 10 s) of the histamine (1 microM)-precontracted preparation caused a contraction followed by a relaxation. Relaxations were inhibited by L-N(G)-nitroarginine (L-NA; EC50 3 microM) in a concentration-dependent manner. The inhibitory action of 10 microM L-NA was blocked by 10 microM L-arginine but not by D-arginine, which indicates that the relaxation was largely mediated by endogenous nitric oxide (NO). Tetrodotoxin (1 microM) reduced the relaxation only by about 50%. GABA and the GABA(B) agonist, baclofen, inhibited the fi…
Coronary artery fistulas as a cause of angina: How to manage these patients?
2015
Abstract Coronary artery fistulas represent the most common hemodynamically significant congenital defect of the coronary arteries and the clinical presentation is mainly dependent on the severity of the left-to-right shunt. We describe a case of a 55-year-old man with history of chest pain and without history of previous significant chest wall trauma or any invasive cardiac procedures. A coronary multislice computed tomography showed two large coronary fistulas arising from the left anterior descending coronary artery and ending in an angiomatous plexus draining into the common pulmonary trunk. Coronary angiography confirmed the CT finding and showed a third fistulous communication arising…
Evaluation by reverse phase HPLC of [3H]acetylcholine release evoked from the myenteric plexus of the rat.
1990
Myenteric plexus-longitudinal muscle strips isolated from the small intestine of rats were incubated with [3H]choline to measure the synthesis and the release of [3H]acetylcholine. To separate different radioactive compounds (acetylcholine, choline, phosphorylcholine) from both the tissue and the overflow a new method, the reverse phase HPLC, was used. The radiochromatogram following the injection of a [3H]choline-standard and a [14C]acetylcholine-standard onto the HPLC showed a clear separation of both isotopes with a recovery rate of roughly 100%. Incubation of the muscle strips with [3H]choline caused the synthesis of [3H]acetylcholine (30,000 dpm/preparation) that increased 2-fold, when…
Presynaptic effects of scopolamine, oxotremorine, noradrenaline and morphine on [3H] acetylcholine release from the myenteric plexus at different sti…
1987
The inhibition by three modulators (oxotremorine, noradrenaline, morphine) of acetylcholine release from the myenteric plexus preincubated with [3H]choline was investigated at different stimulation frequencies and calcium concentrations. Moreover, [3H]acetylcholine release evoked by a low (0.1 Hz) or a high (10 Hz) stimulation rate was investigated at different calcium concentrations either in the absence or presence of scopolamine. A reduced calcium concentration (0.6 mmol/l) inhibited acetylcholine release more at 0.1 Hz (74% +/- 3%) than at 10 Hz (44% +/- 8%). Scopolamine enhanced the stimulated acetylcholine release at a calcium concentration of 1.8 mmol/l. At calcium concentrations hig…
Formation and release of acetylpyrrolidinecholine (N-methyl, N-acetoxyethylpyrrolidinium) as a false cholinergic transmitter in the myenteric plexus …
1977
1. Longitudinal muscle strips of the guineapig small intestine were incubated with Tyrode solution containing the choline analogue pyrrolidinecholine. At the end of the incubation the concentrations of acetylcholine and its analogue acetylpyrrolidinecholine were determined in the strips by gas chromatography. 2. After 120 min of incubation with 1 mM pyrrolidinecholine, acetylpyrrolidinecholine comprised about 15% of the total amount of acetylcholine plus acetylpyrrolidinecholine. Electrical stimulation (1 Hz) of the strips during the incubation slightly increased the proportion of acetylpyrrolidinecholine to 21%. 3. The acetylcholine content of control strips increased significantly during …
Impulse interval-dependent effect of sympathetic nerve stimulation on evoked acetylcholine release from the rabbit perfused atria preparation.
1995
The aim of the present study was to explore possible prejunctional effects mediated by impulse activity of sympathetic terminals on evoked acetylcholine release in an organ innervated by the autonomic ground plexus. Rabbit atria were isolated with the extrinsic right vagus and sympathetic nerves intact and perfused with Tyrode solution. Acetylcholine overflow was determined after labelling of the transmitter stores with [14C]choline and fractionation of the radioactivity on cation exchange columns. The overflow of endogenous noradrenaline was measured by HPLC and electrochemical detection. The vagus nerve was stimulated at 2 Hz for 3 min four times at intervals of 10 min. During the second …
Comparison between local and regional anesthesia in arteriovenous fistula creation.
2011
Purpose Assessment of the effectiveness of Brachial Plexus Block (BPB) via axillary approach compared to regional anesthesia for arteriovenous fistula surgery in patients affected by end-stage renal disease. Methods We compared forty patients randomly divided into two groups. Group A underwent BPB procedure with 15 mL ropivacaine 1% and 10 mL of saline (0.9% NaCl) via axillary approach. Group B received local anesthesia with lidocaine 2%. The forearm blood vessels were assessed by Doppler ultrasonography before and after the intervention. Results BPB performed on Group A was associated with a considerable venous dilation and a significant decrease (48.7%, P<.05) in pulsatility index (PI)…
Late onset of dropped head syndrome following mantle radiation therapy for Hodgkin lymphoma.
2018
Dropped head syndrome (DHS) is a rare condition, characterised by weakness of the cervical paraspinal muscles with sagging of the head. It is usually seen in association with neurological disorders and rarely can follow radiotherapy. We report a case of a 54-year-old man survivor of Hodgkin lymphoma (HL), who developed DHS 28 years after radiotherapy. He was referred to our department due to progressive weakness and atrophy of cervical paraspinal and shoulder girdle musculature. Physical and neurophysiological examination, electromyography and MRI confirmed the diagnosis of DHS. In the following years, there was no progression of symptoms.
Region specific expression of furin mRNA in the rat brain.
1993
The distribution of furin mRNA was examined in the rat central nervous system. Northern blot analysis reveals the presence of a 4.4 kb band in all brain tissues examined. In situ hybridization analysis of frozen rat brain sections using a radioactively labeled antisense cRNA probe to rat furin demonstrated moderate to low levels of expression in both neuronal and non-neuronal tissue in all areas examined. Interestingly, higher levels of furin were expressed in selective regions which include the ventricles (the choroid plexus and ependymal cells), the islands of Calleja, the hippocampus and the pineal gland. the ubiquitous localization of furin in the brain is consistent with its postulated…
In vitro and in vivo porphyrin accumulation by C6 glioma cells after exposure to 5-aminolevulinic acid
1998
Several malignant tissues synthesize endogenous porphyrins after exposure to 5-aminolevulinic acid (5-ALA). The present experiments have been designed to elucidate whether the C6 glioma cell, a model cell for human malignant glioma, similarly synthesizes porphyrins when exposed to 5-ALA, and whether specific synthesis occurs when C6 cells are inoculated into rat brains to form a tumor. In this situation the blood-brain barrier may interfere with 5-ALA availability, and spreading of porphyrins with edema outside the tumor may occur. Flow cytometry is used to determine the course of cell volume and porphyrin fluorescence intensities in cultured C6 cells which are incubated in 1 mM 5-ALA. For …