- Best Practices for Intrathecal Baclofen Therapy: Troubleshooting. [REVIEW, JOURNAL ARTICLE]
- Neuromodulation 2016 Jul 19.
Troubleshooting helps optimize intrathecal baclofen (ITB) therapy in cases of underdose, overdose, and infection.An expert panel of 21 multidisciplinary physicians currently managing >3200 ITB patients was convened, and using standard methodologies for guideline development, created an organized approach to troubleshooting ITB. They conducted a structured literature search that identified 263 peer-reviewed papers, and used results from an online survey of 42 physicians currently managing at least 25 ITB patients each.The panel developed two algorithms. The first was for loss-of-efficacy and applies to patients with previously well-controlled hypertonia on a stable dosing regimen who have increased spasticity Evaluation includes a targeted history (onset, duration, course, exacerbating/relieving factors, medications, recent procedures), physical examination (neuromuscular, vital signs, mental status), radiologic/laboratory testing (catheter imaging, noxious stimuli, infection, rising CK levels), and pump telemetry (pump interrogation, reservoir volume). Rapidly progressing hypertonia with autonomic instability or hypotonia and somnolence require emergent care and perhaps hospitalization. The second algorithm was for emergent care and describes treatment of overdose or withdrawal, which requires immediate care in a monitored setting and restoration of ITB delivery. The previous dosing schedule can be used in withdrawal of short duration; 10-20 mg every six hours can be used in longer-duration withdrawal. Supportive care includes maintenance of airway, respiration, and circulation. Seizure prevention should be considered, along with pump reprogramming or interruption, cerebrospinal fluid drainage, and sequential lumbar punctures/drains. Physostigmine and flumazenil are not usually advised. Superficial infections can be treated with oral antibiotics, and deep infections with broad-spectrum IV antibiotics (e.g., cefazolin, clindamycin, vancomycin). Explantation is often required. A new pump can be implanted in a new site under IV antibiotic coverage.Orderly troubleshooting helps ensure patient safety.
- Imaging of Cerebral α4β2* Nicotinic Acetylcholine Receptors with (-)-[()F]Flubatine PET: Implementation of Bolus Plus Constant Infusion and Sensitivity to Acetylcholine in Human Brain. [JOURNAL ARTICLE]
- Neuroimage 2016 Jul 14.
The positron emission tomography (PET) radioligand (-)-[(18)F]flubatine is specific to α4β2(⁎) nicotinic acetylcholine receptors (nAChRs) and has promise for future investigation of the acetylcholine system in neuropathologies such as Alzheimer's disease, schizophrenia, and substance use disorders. The two goals of this work were to develop a simplified method for α4β2(⁎) nAChR quantification with bolus plus constant infusion (B/I) (-)-[(18)F]flubatine administration, and to assess the radioligand's sensitivity to acetylcholine fluctuations in humans. Healthy human subjects were imaged following either bolus injection (n=8) or B/I (n=4) administration of (-)-[(18)F]flubatine. The metabolite-corrected input function in arterial blood was measured. Free-fraction corrected distribution volumes (VT/fP) were estimated with modeling and graphical analysis techniques. Next, sensitivity to acetylcholine was assessed in two ways: 1. A bolus injection paradigm with two scans (n=6), baseline (scan 1) and physostigmine challenge (scan 2; 1.5 mg over 60 min beginning 5 min prior to radiotracer injection); 2. A single scan B/I paradigm (n=7) lasting 210-240 min with 1.5 mg physostigmine administered over 60 min beginning at 125 min of radiotracer infusion. Changes in VT/fP were measured. Baseline VT/fP values were 33.8±3.3 mL/cm(3) in thalamus, 12.9±1.6 mL/cm(3) in cerebellum, and ranged from 9.8-12.5 mL/cm(3) in other gray matter regions. The B/I paradigm with equilibrium analysis at 120 min yielded comparable VT/fP values with compartment modeling analysis of bolus data in extrathalamic gray matter regions (regional means <4% different). Changes in VT/fP following physostigmine administration were small and most pronounced in cortical regions, ranging from 0.8-4.6% in the two-scan paradigm and 2.8-6.5% with the B/I paradigm. These results demonstrate the use of B/I administration for accurate quantification of (-)-[(18)F]flubatine VT/fP in 120 min, and suggest possible sensitivity of (-)-[(18)F]flubatine binding to physostigmine-induced changes in acetylcholine levels.
- EXPRESSION AND EFFECTS OF MUTANT Bombyx mori ACETYLCHOLINESTRASE1 IN BmN CELLS. [JOURNAL ARTICLE]
- Arch Insect Biochem Physiol 2016 Jul 12.
The main mechanism of toxicity of organophosphate (OP) and carbamate (CB) insecticides is their irreversible binding and inhibition of acetylcholinestrase (AChE), encoded by ace1 (acetylcholinestrase gene 1), leading to eventual death of insects. Mutations in AChE may significantly reduce insects susceptibility to these pesticides. Bombyx mori is an important beneficial insect, and no OP- or CB-resistant strains have been generated. In this study, wild-type ace1 (wace1) and mutant ace1 (mace1) were introduced into BmN cells, confirmed by screening and identification. The expression of wace1 and mace1 in the cells was confirmed by Western blot and their expression levels were about 21-fold higher than the endogenous ace1 level. The activities of AChE in wace1 and mace1 transgenic cells were 10.6 and 20.2% higher compared to control cells, respectively. mace1 transgenic cells had higher remaining activity than wace1 transgenic cells under the treatment of physostigmine (a reversible cholinesterase inhibitor) and phoxim (an OP acaricide). The results showed that ace1 transgene can significantly improve ace1 expression, and ace1 mutation at a specific site can reduce the sensitivity to AChE inhibitors. Our study provides a new direction for the exploration of the relationship between AChE mutations and drug resistance.
- Increased cell proliferation and neural activity by physostigmine in the telencephalon of adult zebrafish. [JOURNAL ARTICLE]
- Neurosci Lett 2016 Jul 1.:189-195.
Physostigmine, an acetylcholinesterase inhibitor, is known to affect the brain function in various aspects. This study was conducted to test whether physostigmine affects cell proliferation in the telencephalon of zebrafish. BrdU-labeled cells was prominently observed in the ventral zone of the ventral telencephalon of zebrafish. The increased number of BrdU- and proliferating cell nuclear antigen-labeled cells were shown in zebrafish treated with 200μM physostigmine, which was inhibited by pretreatment with 200μM scopolamine. iNOS mRNA expression was increased in the brain of zebrafish treated with 200μM physostigmine. Consistently, aminoguanidine, an iNOS inhibitor, attenuated the increase in the number of BrdU-labeled cells by physostigmine treatment. Zebrafish also showed seizure-like locomotor activity characterized by a rapid and abrupt movement during a 30min treatment with 200μM physostigmine. Neural activity in response to an electrical stimulus was increased in the isolated telencephalon of zebrafish continuously perfused with 200μM physostigmine. None of the number of BrdU-labeled cells, neural activity, or locomotor activity was affected by treatment with 20μM physostigmine. These results suggest that 200μM physostigmine increased neural activity and induced cell proliferation via nitric oxide production in zebrafish.
- Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby. [Journal Article]
- Plant Signal Behav 2016 Jun 2; 11(6):e1187355.
We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10(-4) M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10(-5) M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants.
- Cholinesterase in porcine saliva: Analytical characterization and behavior after experimental stress. [Journal Article]
- Res Vet Sci 2016 Jun.:23-8.
The purpose of this study was to measure and characterize the enzyme cholinesterase (ChE) in porcine saliva, as well as to evaluate its behavior in experimental stressful conditions. The results of ChE characterization by using different substrates and the selective inhibitors ethopropazine and physostigmine showed that the main enzyme existing in porcine saliva was butyrylcholinesterase (BChE). An automated assay using butyrylthiocholine iodide as substrate was validated providing adequate reproducibility, linearity results and limit of detection. Salivary ChE was measured using the validated assay in two models of acute stress: twenty pigs stressed for 2min with a nasal snare and other twenty pigs subjected to a short-term road transport. Salivary ChE significantly increased after restraint and transport stress in pigs, as well as the ChE to total protein ratio. In conclusion, BChE is the predominant isoenzyme in porcine saliva, it can be measured by the fast, simple and automated method described in this paper and it increases in the models of stress used in this study.
- [Anti-inflammatory effect of acetylcholine on lipopolysaccharide induced inflammatory response of alveolar macrophages]. [English Abstract, Journal Article]
- Zhonghua Wei Zhong Bing Ji Jiu Yi Xue 2015 Oct; 27(10):811-5.
To observe the effect of acetylcholine (ACh) on lipopolysaccharide (LPS) induced inflammatory model of rat alveolar macrophages, and to observe the effect of the acetylcholinesterase inhibitor physostigmine (Phy) on the anti-inflammatory effect of ACh.The rat alveolar macrophages NR8383 were cultured in vitro, which were divided into five groups: blank control group, LPS group (stimulated with 1 mg/L LPS for 12 hours), LPS + ACh group (0.01, 0.1, 1, 10, 100 μmol/L of ACh were added for 5 minutes before LPS stimulation), LPS + Phy group (1 mmol/L Phy was added for 5 minutes before LPS stimulation), and LPS + ACh + Phy group (1 mmol/L Phy and 10 μmol/L ACh were added for 5 minutes before LPS stimulation). The supernatants were collected in each group, the enzyme-linked immunosorbent assay (ELISA) was used to assay the contents of tumor necrosis factor-α (TNF-α), interleukins (IL-1β, and IL-6). The activity of acetylcholine esterase (AChE ) in the supernatant was also determined.(1) The contents of TNF-α (ng/L: 605.09 ± 57.13 vs. 34.07 ± 8.62), IL-1β (ng/L: 377.09 ± 28.55 vs. 32.33 ± 10.62) and IL-6 (ng/L: 558.04 ± 77.45 vs. 42.62 ± 11.21) in the LPS group were significantly higher than those in the blank control group (all P < 0.05). These results indicated that the inflammatory model of rat alveolar macrophages was constructed successfully. (2) ACh with the final concentrations of 0.01, 0.1, and 1 μmol/L had less influence on the production of TNF-α, IL-1β and IL-6 in the culture supernatants of alveolar macrophages stimulated with LPS compared with LPS group (all P > 0.05). Nevertheless, 10 μmol/L and 100 μmol/L ACh notably reduced the production of TNF-α (ng/L: 451.19 ± 30.67, 332.19 ± 32.19 vs. 604.96 ± 22.56), IL-1β (ng/L: 261.08 ± 24.78, 143.98 ± 28.39 vs. 367.06 ± 10.44) and IL-6 (ng/L: 342.75 ± 54.60, 235.48 ± 29.75 vs. 562.69 ± 63.34) in the culture supernatants compared with the LPS group (all P < 0.05). (3) The activity of AChE in the LPS group was significantly higher than that in the blank control group (kU/L: 5.21 ± 0.63 vs. 3.09 ± 0.10, P < 0.05). The activity of AChE was successfully inhibited by 1 mmol/L acetylcholinesterase inhibitor Phy pretreatment compared with that in the LPS group (1.51 ± 0.12 vs. 5.21 ± 0.63, P < 0.05). (4) The level of TNF-α (ng/L: 183.17 ± 35.44 vs. 451.19 ± 30.67), IL-1β (ng/L: 91.49 ± 12.27 vs. 261.08 ± 24.78) and IL-6 (ng/L: 108.17 ± 22.82 vs. 342.75 ± 54.60) in the culture supernatants of LPS + ACh + Phy group was significantly decreased as compared with LPS + ACh group (all P < 0.05).ACh with the final concentrations of 10 μmol/L and 100 μmol/L can inhibit the LPS induced inflammatory reaction in alveolar macrophages. The acetylcholinesterase inhibitor Phy can reinforce the ACh-mediated anti-inflammatory effect on alveolar macrophages inflammatory model.
- Neuroinflammation: effect of surgical stress compared to anaesthesia and effect of physostigmine. [Journal Article]
- Neurol Res 2016 May; 38(5):397-405.
Surgical interventions can cause systemic postoperative inflammation, which in turn can induce neuroinflammation. A close link between immune reaction and cholinergic metabolism has been postulated. Pharmacological enhancement of cholinergic activity by administering physostigmine is known to induce protective effects. It is not known, however, whether physostigmine has an impact on postoperative inflammation and acetylcholine metabolism after a partial liver resection (PLR) surgery.Rats (n = 100) underwent a PLR or sham surgery. Rats were investigated before the intervention and 120 min and 24 h postoperatively. The control group only received sevoflurane anaesthesia. Half of each treatment group received a single intraoperative dose of physostigmine, whereas the others were given placebo. Acetylcholine (ACHE) and butyrylcholinesterase (BuCHE) activity and IL1β, IL6 and corticosterone levels were measured in rat plasma and brain. Acetylcholine (ACH) concentrations were determined additionally in cerebral tissue.Surgical interventions induced a peripheral stress reaction, which was characterized by an increase (p < 0.05) in pro-inflammatory cytokines, cholinergic esterases and corticosterone at 120 min postoperatively in rat blood and in cerebral tissue. At 24 h postoperatively, all measured cerebral parameters reached control values. In blood, IL1β and BuCHE were still increased, suggesting they are peripheral markers of a stress reaction. The reduced cerebral acetylcholine is increased after physostigmine administration. Furthermore, physostigmine reduced IL1β (p < 0.05).We show in this observational study that a single intraoperative dose of physostigmine produced a sustained anti-inflammatory effect in rat blood and brain up to 120 min postoperatively, which was especially pronounced under the condition of PLR surgery.
- Tramadol state-dependent memory: involvement of dorsal hippocampal muscarinic acetylcholine receptors. [Journal Article]
- Behav Pharmacol 2016 Aug; 27(5):470-8.
The effects on tramadol state-dependent memory of bilateral intradorsal hippocampal (intra-CA1) injections of physostigmine, an acetylcholinesterase inhibitor, and atropine, a muscarinic acetylcholine receptor antagonist, were examined in adult male NMRI mice. A single-trial step-down passive avoidance task was used for the assessment of memory retention. Post-training intra-CA1 administration of an atypical μ-opioid receptor agonist, tramadol (0.5 and 1 μg/mouse), dose dependently impaired memory retention. Pretest injection of tramadol (0.5 and 1 μg/mouse, intra-CA1) induced state-dependent retrieval of the memory acquired under the influence of post-training tramadol (1 μg/mouse, intra-CA1). A pretest intra-CA1 injection of physostigmine (1 μg/mouse) reversed the memory impairment induced by post-training administration of tramadol (1 μg/mouse, intra-CA1). Moreover, pretest administration of physostigmine (0.5 and 1 μg/mouse, intra-CA1) with an ineffective dose of tramadol (0.25 μg/mouse, intra-CA1) also significantly restored retrieval. Pretest administration of physostigmine (0.25, 0.5, and 1 μg/mouse, intra-CA1) by itself did not affect memory retention. A pretest intra-CA1 injection of the atropine (1 and 2 μg/mouse) 5 min before the administration of tramadol (1 μg/mouse, intra-CA1) dose dependently inhibited tramadol state-dependent memory. Pretest administration of atropine (0.5, 1, and 2 μg/mouse, intra-CA1) by itself did not affect memory retention. It can be concluded that dorsal hippocampal muscarinic acetylcholine receptor mechanisms play an important role in the modulation of tramadol state-dependent memory.
- Muscarinic acetylcholine receptor-mediated stimulation of retinal ganglion cell photoreceptors. [Journal Article]
- Neuropharmacology 2016 Sep.:305-15.
Melanopsin-dependent phototransduction in intrinsically photosensitive retinal ganglion cells (ipRGCs) involves a Gq-coupled phospholipase C (PLC) signaling cascade. Acetylcholine, released in the mammalian retina by starburst amacrine cells, can also activate Gq-PLC pathways through certain muscarinic acetylcholine receptors (mAChRs). Using multielectrode array recordings of rat retinas, we demonstrate that robust spiking responses can be evoked in neonatal and adult ipRGCs after bath application of the muscarinic agonist carbachol. The stimulatory action of carbachol on ipRGCs was a direct effect, as confirmed through calcium imaging experiments on isolated ipRGCs in purified cultures. Using flickering (6 Hz) yellow light stimuli at irradiances below the threshold for melanopsin activation, spiking responses could be elicited in ipRGCs that were suppressed by mAChR antagonism. Therefore, this work identified a novel melanopsin-independent pathway for stimulating sustained spiking in ganglion cell photoreceptors. This mAChR-mediated pathway could enhance ipRGC spiking responses in conditions known to evoke retinal acetylcholine release, such as those involving flickering or moving visual stimuli. Furthermore, this work identifies a pharmacological approach for light-independent ipRGC stimulation that could be targeted by mAChR agonists.