Disease relevance of Denervation

• Cyclosporine-induced hypertension is associated with sympathetic neural activation, which may be accentuated by the cardiac denervation that results from heart transplantation [1].
• Sprouting of synapses after partial denervation of frag cardic ganglion [2].
• Serotonergic denervation partially protects rat striatum from kainic acid toxicity [3].
• Nevertheless, (a) minimal alteration of endogenous glucose production, (b) increased concentration of insulin and glucagon, and (c) defective counterregulation during hypoglycemia may reflect an alteration of the liver-CNS-islet circuit which is due to denervation of the transplanted graft [4].
• In vitro, short-circuit current changes to exogenously added l-epinephrine were significantly greater in diabetics, suggesting that denervation hypersensitivity was due to increased numbers of postsynaptic alpha 2-adrenergic receptors [5].

Psychiatry related information on Denervation

• Inappropriate sexual behavior and denervation supersensitivity of limbic and midbrain LHRH receptors in Tourette's syndrome [6].
• A regional cholinergic denervation of both cortical microvessels and reduced nicotinamide adenine dinucleotide phosphate-diaphorase neurons was found in Alzheimer's disease patients as compared to aged controls, and it paralleled the loss of total cholinergic nerve terminals in the corresponding areas of the cerebral cortex [7].
• The spontaneous motor activity in these mice was profoundly and persistently depressed (-66%) as a result of the MPTP-induced DA denervation and the motor deficit was completely reversed by L-DOPA treatment [8].
• D1 dopamine receptor-mediated substance P depletion in the striatonigral neurons of rats subjected to neonatal dopaminergic denervation: implications for self-injurious behavior [9].
• Huntington's chorea is characterized by more prominent striatal dopamine receptor loss, whereas nigrostriatal denervation is present to a lesser degree [10].

High impact information on Denervation

• Immunohistochemical detection of myofibers expressing the neural-cell adhesion molecule corroborated ongoing denervation in both patient groups [11].
• However, nigrostriatal denervation produces a concomitant depletion of striatal DA [12].
• Denervation of newborn rat muscle does not block the appearance of adult fast myosin heavy chain [13].
• Denervation supersensitivity in the striatonigral GABA pathway [14].
• Effect of denervation and local damage on extrajunctional L-glutamate receptors in locust muscle [15].

Chemical compound and disease context of Denervation

• Pathophysiologic theories postulate that tardive dyskinesia arises from the development of chemical denervation supersensitivity of dopamine receptors produced by chronic long-term neuroleptic treatment [16].
• Conversely, intravenous infusion of norepinephrine preferentially shortened the effective refractory period of sites in the ischemic zone, thereby indicating that denervation hypersensitivity had occurred at these sites [17].
• Conclusions are that 1) MIBG can be used noninvasively to determine the presence of regional myocardial efferent sympathetic denervation and subsequent reinnervation, 2) reinnervation occurs after phenol application or transmural myocardial infarction, and 3) denervation supersensitivity persists even after reinnervation occurs [18].
• We used myocardial ischemia and chemical stimuli to increase the activity of the sensory endings in 15 chloralose-anesthetized, mechanically ventilated dogs with sinoaortic denervation and vagotomy [19].
• The antinatriuretic response to acute hypercapnic acidosis could be attenuated significantly by surgical renal denervation, intrarenal phenoxybenzamine, and by intrarenal infusion of 1-sarcosine,8-glycine angiotensin II [20].

Biological context of Denervation

• Surgical denervation of the adrenal gland or pharmacologic blockade of synaptic transmission, treatments known to decrease catecholamine traits, increased [Leu]enkephalin content [21].
• In contrast, renal denervation, intravenous bretylium (10 mg/kg), intravenous atropine (0.5 mg/kg) or intrarenal SQ 20881 (0.20 mg/min) has no effect on postarrhythmic renal vasoconstriction [22].
• The effects of denervation were investigated in mice with transgenes containing promoter elements from the muscle acetylcholine receptor epsilon- and alpha-subunit genes [23].
• To determine if the down-regulation of myogenin and MyoD mRNA levels during development is due to innervation, we quantitated message levels in adult calf muscles after denervation [24].
• Blockade of the TNS-induced vasodilation by tetrodotoxin (TTX) or cold storage denervation did not prevent the arteries from relaxing in response to ACh or methacholine (MCh) [25].

Anatomical context of Denervation

• Here we demonstrate that a reserpine-induced depletion of DA produces a decrease in D-3 binding comparable to that seen with nigrostriatal denervation, independent of presynaptic terminal degeneration [12].
• Moreover, increased efficacy of Bay K 8644 was maintained for at least 24 h after denervation produced by removal of ganglia from the culture [26].
• Fibers immunoreactive for 5-HT3R in the duodenal but not ileal mucosa were markedly reduced by subdiaphragmatic vagotomy or chemical denervation of vagal afferents [27].
• METHODS: Six groups of rats were studied: control, chemical denervation (3 mmol/L BAC), surgical denervation, intraluminal stasis produced by partial obstruction, chemical inflammation (5% acetic acid), and surgical inflammation (serosa removal only) [28].
• Skeletal muscle denervation activates acetylcholine receptor genes [29].

Associations of Denervation with chemical compounds

• Denervation thus causes the clustered junctional acetylcholine receptors to assume the rapid turnover characteristic of extrajunctional receptors before innervation [30].
• These observations suggest that an increase in alphaadrenergic receptor numbers may account for the denervation supersensitivity to infused norepinephrine in patients with sympathetic degeneration [31].
• Consistent with this concept, we show here that selective sensory-fiber denervation with capsaicin and targeted deletion of the PPT-A gene protect murine lungs against both immune complex-mediated and stretch-mediated injuries [32].
• The enhancement of ileal glucose absorption was half-maximal in 40-45 d, could be reversed by 10 d of treatment with insulin and did not result from adrenergic denervation [33].
• Changes in glomerular hemodynamic response to angiotensin II after subacute renal denervation in rats [34].

Gene context of Denervation

• Accelerated response of the myogenin gene to denervation in mutant mice lacking phosphorylation of myogenin at threonine 87 [35].
• Four AML1 transcripts are expressed in denervated muscle, and the abundance of each transcript increases after denervation [36].
• Natural history of denervation in SMA: relation to age, SMN2 copy number, and function [37].
• The comparable response to leptin under intravenous or intracerebroventricular infusion and the loss of responsiveness after denervation strongly suggest that the acute effects of leptin involve central signaling pathways [38].
• In conclusion, our observations strongly indicate that myenteric denervation in acute-phase T. cruzi infection is because of IFN-gamma-elicited NO production resulting from iNOS activation in the inflammatory foci along the intestinal wall [39].

Analytical, diagnostic and therapeutic context of Denervation

• Adrenal denervation and hypophysectomy selectively block the increases in cofactor level in medulla and cortex, respectively, while cycloheximide prevents the increase in both tissues [40].
• Successful denervation was demonstrated by absence of a contractile response to electrical stimulation, supersensitivity to exogenous norepinephrine, an extremely low content of endogenous norepinephrine, reduced accumulation of 3H-norepinephrine, and inability of electrical stimulation and tyramine to augment the overflow of 3H-norepinephrine [41].
• We conclude that TMI produced by latex injection and ligation of multiple coronary arteries produces heterogeneous loss of efferent sympathetic innervation in noninfarcted apical sites as early as 5-20 minutes after coronary occlusion with more complete denervation occurring over time.(ABSTRACT TRUNCATED AT 400 WORDS)[42]
• Adrenal enucleation or denervation of the adrenal gland by suprarenal ganglionectomy prevented vagotomy-induced decrease in baseline paw withdrawal threshold and enhancement of bradykinin-induced hyperalgesia [43].
• Quantitative autoradiography of 3H-SP binding to striatal sections in vitro also failed to reveal any effects of dopamine denervation [44].

References