Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endoneurial hypoxia of ischaemic origin is believed to cause the reduction in sciatic nerve substance P levels in experimentally diabetic rats. The first part of this study was designed to determine whether the changes seen extended to another neuropeptide, calcitonin gene-related peptide, and to reveal any correlation between substance P and calcitonin gene-related peptide levels in the sciatic nerve of both diabetic and centrally hypoxaemic rats. Comparison of streptozotocin diabetic rats (four-week duration) with their control group showed clear reductions in both substance P-like immunoreactivity (control = 225 +/- 20 pg/mg protein, diabetic = 139 +/- 19; P < 0.01) and calcitonin gene-related peptide-like immunoreactivity (control = 9.08 +/- 0.65 ng/mg protein, diabetic = 4.43 +/- 0.44; P < 0.001). A similar pattern was seen with the comparison of five-week centrally hypoxaemic rats (housed in 10% O2) with their controls for both substance P-like immunoreactivity (control = 222 +/- 10 pg/mg protein, hypoxic = 148 +/- 13; P < 0.001) and calcitonin gene-related peptide-like immunoreactivity (control = 6.58 +/- 0.42 ng/mg protein, hypoxic = 3.01 +/- 0.45; P < 0.001). Calcitonin gene-related peptide levels correlated closely with substance P levels in both the diabetes and central hypoxaemia studies (r2 = 0.69 and 0.62, respectively). The second part of this study measured the messenger RNA levels of the substance P precursor, preprotachykinin-A, and calcitonin gene-related peptide messenger RNA in the L4 and L5 dorsal root ganglia of control, diabetic and centrally hypoxaemic rats. There was no change in preprotachykinin-A or calcitonin gene-related peptide messenger RNA levels between any of the groups, suggesting that the sciatic nerve decreases in substance P and calcitonin gene-related peptide described above are post-transcriptional in origin.
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PMID:Reduced sciatic nerve substance P and calcitonin gene-related peptide in rats with short-term diabetes or central hypoxaemia co-exist with normal messenger RNA levels in the lumbar dorsal root ganglia. 751 37

Small fiber sensory neuropathy is one of the most common complications of diabetes mellitus. Currently there is no adequate therapy to prevent this often debilitating problem. Nerve growth factor (NGF) is a protein that promotes the survival and integrity of a large percentage of sensory neurons including the small fiber pain transmitting neurons which are often prominently affected in diabetic neuropathy. We report here that exogenously administered NGF is capable of preventing the behavioral and biochemical manifestations of diabetic sensory neuropathy in a streptozocin induced rat model. NGF administration prevented the elevation of tailflick threshold (a measure of the rat's response to a thermal noxious stimulus) which occurred in streptozocin-induced diabetic rats. Further, it prevented the induced reduction in levels of the neuropeptides substance P and calcitonin gene related peptide measured from cervical dorsal root ganglia. Finally, NGF did not ameliorate the prolonged latency of the compound action potentials measured from the caudal nerve of the tail. In view of these results, a clinical trial of NGF in diabetic neuropathy has now commenced.
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PMID:Nerve growth factor administration protects against experimental diabetic sensory neuropathy. 751 29

Rats with streptozotocin-induced diabetes of 4 to 6 weeks duration showed a depletion of both substance P (P < 0.01) and calcitonin gene-related peptide (P < 0.01) in the sciatic nerve. Since expression of both peptides is sensitive to nerve growth factor (NGF) in vitro we examined the effect of treatment of diabetic rats with NGF, which significantly increased the levels of both peptides in treated diabetic animals (P < 0.01 for both). Treatment of non-diabetic rats with a similar NGF regime raised the mean peptide levels to a value similar to that seen in treated diabetic rats but the change was not statistically significant. In vehicle-treated diabetic rats the depletions of sciatic nerve neuropeptides were accompanied by a significant (P < 0.05) reduction in the level of CGRP mRNA in the 4th and 5th lumbar dorsal root ganglia, this was accompanied by an analogous reduction in the mRNA for gamma-preprotachykinin A (gamma-PPT), which did not attain statistical significance. Treatment of diabetic rats with NGF also prevented the deficits in the levels of CGRP and gamma-PPT mRNA in the lumbar dorsal root ganglia (P < 0.05). Treatment of other diabetic rats with the related neurotrophin, brain-derived neurotrophic factor (BDNF), had no effect on the levels of substance P and calcitonin gene-related peptide in the sciatic nerve.
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PMID:Expression of neuropeptides in experimental diabetes; effects of treatment with nerve growth factor or brain-derived neurotrophic factor. 751 41

Dorsal root ganglion neurons from streptozotocin (STZ)-induced diabetic, genetic diabetic and normal mice were cultured in serum-containing media with or without nerve growth factor (NGF). The immunocytochemical analysis carried out after 1 week in culture revealed that the ratios of neurons immunoreactive to calcitonin gene-related peptide (CGRP) in NGF-free medium in the STZ-diabetic mice (average 23.2%) were significantly lower than those in the normal mice (45.1%). The ratios of neurons immunoreactive to CGRP and substance P (SP) in the NGF-free medium were also lower in the genetic diabetic mice (23.6% and 21.8%) than those in the normal ones (40.7% and 34.2%). However, treatment with NGF restored these reduced immunoreactivities in the diabetic groups in a dose-dependent manner. These results show that NGF can be effective for the diabetes-induced depletion of CGRP and SP in sensory neurons, and suggest its possible role in the prevention and improvement of diabetic sensory neuropathy.
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PMID:Nerve growth factor (NGF) restores depletions of calcitonin gene-related peptide and substance P in sensory neurons from diabetic mice in vitro. 753 Jul 67

This study examined the expression of the sensory neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), in the lumbar 4 and 5 dorsal root ganglion (DRG) and spinal cord of spontaneously diabetic BB rats and non-diabetic controls using quantitative immunohistochemical analysis. In both animal groups immunoreactivities for CGRP and SP were widely distributed within the neurons of DRG and in nerve fibres of the dorsal spinal cord. Image analysis of each neuropeptide subpopulation in the DRG showed that in diabetic rats the cell diameter of immunostained CGRP neurons was significantly decreased compared with controls, while no difference could be found for SP-immunoreactive (IR) neurons. The decrease in the CGRP-IR cell diameter appeared to occur mainly in medium to large neurons (30-50 microns diameter; 2.2% controls, < 1% diabetes), this change being parallel to an increased frequency of small-size neurons (< 20 microns diameter) in diabetic rats (62% controls, 69% diabetes; P < 0.05). However, there was no statistical difference in the total number of cells immunostained for either CGRP or SP between control and diabetic rats. The ratio of CGRP or SP neurons compared to total cells in the ganglion was similar in control and diabetic groups. No difference could be observed for peptide immunoreactivity in the dorsal and ventral horns of either control or diabetic animals. The observed changes of perikaryal size in diabetic rats might relate to the reduced axonal calibre and conduction velocity observed in these animals, and indicate that subpopulations of sensory neurons are affected differently by diabetes.
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PMID:Changes in sensory neuropeptides in dorsal root ganglion and spinal cord of spontaneously diabetic BB rats. A quantitative immunohistochemical study. 753 45

The in vitro responses of rat urinary bladder, to substance P and capsaicin were studied at 1, 4, 16, and 26 weeks of diabetes induction by streptozotocin. We also studied the role of epithelium in these responses. The results were compared with those obtained in age-matched control rats. The bladder contractile response to exogenous substance P was similar in both groups at all stages (1-26 weeks) studied, whereas the bladder response to capsaicin gradually decreased with the progression of diabetes. Atropine did not inhibit these responses whereas indomethacin slightly reduced substance P- but not capsaicin-induced responses in control and diabetic rats. The removal of epithelium slightly increased the substance P- and capsaicin-induced responses in control tissue; these responses were significantly reduced in tissue excised from diabetic rats. Our results indicate that, in rat urinary bladder, diabetes (1) provokes an impairment of capsaicin-sensitive sensory fibers but not of the cholinergic system even at an early stage (4 weeks) of the disease, (2) has no effect on the sensitivity of smooth muscle cells to substance P, (3) stimulates the release of epithelial contracting factors, partially non-prostanoic. Furthermore epithelium removal impairs acetylcholine-induced contraction in bladder excised from diabetic rats but not in controls.
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PMID:Effect of substance P and capsaicin on urinary bladder of diabetic rats and the role of the epithelium. 753 29

This study examined the sciatic nerve axonal transport of substance P-like immunoreactivity (SPLI) and its basal content in stomach, sciatic nerve and lumbar spinal cord of 8- and 12-week alloxan-diabetic rats, respectively. One group of diabetic rats received acetyl-l-carnitine (ALCAR) throughout the experimental period. Alloxan treatment caused hyperglycemia and reduced boy growth. Axonal transport of SPLI was studied by measurement of 24-hour accumulation at a ligature on the sciatic nerve. There was a marked reduction (from 50% to 100% according to the nerve segment examined) of anterograde and retrograde accumulation of SPLI in the constricted nerve of 8-week diabetic rats. In the sciatic nerve of ALCAR-treated diabetic rats, the accumulation of SPLI was comparable to control values. In the sciatic nerve, lumbar spinal cord and stomach of 12-week diabetic rats, there is a significant reduction of SPLI content. ALCAR treatment prevented SPLI loss in these tissues. Sciatic nerves showed the typical sorbitol increase and myo-inositol loss that were significantly counteracted by ALCAR. This study suggests that ALCAR treatment prevents diabetes-induced sensory neuropathy by improving altered metabolic pathways such as polyol activity and myo-inositol synthesis, and by preventing the reduction of synthesis and axonal transport of substance P.
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PMID:Diabetic neuropathy in the rat: 1. Alcar augments the reduced levels and axoplasmic transport of substance P. 753 69

Complications of diabetes include sensory and autonomic neuropathy. The aim of the present paper was to study the degree of sensory and autonomic neuropathy and correlate these findings with the distribution and density of neuropeptidergic nerve fibers in the skin of the forearm of diabetic patients and healthy controls. We investigated 30 diabetics (24 type 1 and 6 type 2) and compared them with 13 healthy controls. There were no differences between the groups with respect to density and distribution of nerve fibers displaying immunoreactivity to the pan-neuronal marker PGP 9.5 and sensory and parasympathetic neuropeptides (substance P, calcitonin gene-related peptide and vasoactive intestinal peptide). By contrast, nerve fibers containing neuropeptide Y, a marker of sympathetic neurons, were reduced in number in the diabetic patients. C-fiber function (measured as the axon-reflex-evoked flare response) became impaired with increasing age in all subjects. The diabetic patients, however, showed a reduced flare compared to age-matched healthy controls. The reduction was particularly prominent in the younger patients (20-50 years). There was a greater reduction of the flare in neuropathic patients than in non-neuropathic patients, but there was no correlation between the degree of functional impairment and the duration of the disease.
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PMID:Innervation of the skin of the forearm in diabetic patients: relation to nerve function. 753 56

The in vitro responses of longitudinal preparations of rat stomach fundus and ileum to capsaicin at 1, 8, 4, 16 and 26 weeks and to substance P at 1 and 8 weeks from diabetes induction were studied. The results were compared with those obtained in age-matched control rats. The contractile responses to exogenous substance P and capsaicin were not affected in the stomach fundus from diabetic rats. Atropine (1 microM) did not antagonize the substance P-induced response whereas it inhibited about 90% of the capsaicin-induced response in controls and about 60% of the response in diabetic rats. At the resting tone, capsaicin induced a relaxation followed by a contraction in stomach fundus of control rats. Only a contraction was evoked in diabetic rats. In carbachol (0.05-0.1 microM) pre-stimulated strips, a complete restoration of the biphasic response was obtained in the diabetic state. The contractile response elicited by exogenous substance P was not significantly increased in the ileum preparations from diabetic rats; nevertheless the EC50 value for substance P was reduced 8 weeks after the onset of diabetes. The response elicited by capsaicin in the ileum of control rats was also biphasic. The capsaicin-induced contraction was greater in tissue from diabetic rats as compared with controls and relaxation was not evident. An age-related decrease of the contraction was also evident in both groups. Atropine (1 microM) partially antagonized the responses to substance P and capsaicin. The inhibition of the responses with atropine was more evident in control than in diabetic rats. These results suggest that the myogenic actions of several agonists in these two tissues are differently modified in experimental diabetes.
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PMID:Effect of substance P and capsaicin on stomach fundus and ileum of streptozotocin-diabetic rats. 754 Jan 41

The extranuclear endogenous mono-ADP-ribosylation of proteins in cellular fractions from retinas of control and diabetic rats was studied. At least six proteins were ADP-ribosylated in the crude extract, membrane and cytosolic fractions from control preparations, whereas in diabetic rats the number of labeled proteins and the extent of labeling were highly reduced. Treatment of diabetic animals with silybin, a flavonoid with ADP-ribosyltransferase inhibitory activity, did not affect hyperglycemia, but prevented the alterations of the extent of ADP-ribosylation of the 38 K cytosolic, 39 K, 40 K membrane and 39 K, 41 K and 42 K crude extract proteins. These data suggest a hyperactivity of extranuclear endogenous protein mono-ADP-ribosylation in the diabetic rat retina, and that treatment with silybin inhibits such enzyme activity, thus improving the extent of ADP-ribosylation. Sciatic nerve axonal transport of substance P was reduced markedly in diabetic rats, and inhibition of mono-ADP-ribosylation with silybin prevented such a loss in spite of high blood glucose levels. These results suggest that the abnormal endogenous ADP-ribosylation of proteins might play a role in the onset of diabetic peripheral neuropathy and its inhibition may represent a novel pharmacological approach to the treatment of diabetes complications.
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PMID:Experimental diabetic neuropathy. Inhibition of protein mono-ADP-ribosylation prevents reduction of substance P axonal transport. 754 40


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