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Hahm SC, Yoon YW, Kim J. High-Frequency Transcutaneous Electrical Nerve Stimulation Alleviates Spasticity After Spinal Contusion by Inhibiting Activated Microglia in Rats. Neurorehabil Neural Repair 2014; 29:370-81. [DOI: 10.1177/1545968314545172] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background. Transcutaneous electrical nerve stimulation (TENS) can be used as a physical therapy for spasticity, but the effects of TENS on spasticity and its underlying mechanisms remain unclear. Objective. The purpose of this study was to test the effects of TENS on spasticity and the role of activated microglia as underlying mechanisms of TENS treatment for spasticity in rats with a 50-mm contusive spinal cord injury (SCI). Methods. A spinal contusion was made at the T12 spinal segment in adult male Sprague-Dawley rats using the NYU impactor. Behavioral tests for motor function were conducted before and after SCI and before and after TENS application. To assess spasticity, the modified Ashworth scale (MAS) was used before and after SCI, high-frequency (HF)/low-frequency (LF) TENS application at 3 different intensities (motor threshold [MT], 50% and 90% MT) or minocycline administration. Immunohistochemistry for microglia was performed at the lumbar spinal segments. Results. Motor recovery reached a plateau approximately 28 days after SCI. Spasticity was well developed and was sustained above the MAS grade of 3, beginning at 28 days after SCI. HF-TENS at 90% MT significantly alleviated spasticity. Motor function did not show any significant changes with LF- or HF-TENS treatment. HF-TENS significantly reduced the proportion of activated microglia observed after SCI. Minocycline, the microglia inhibitor, also significantly alleviated spasticity with the reduction of activated microglia expression. Conclusions. These results suggest that HF-TENS at 90% MT alleviates spasticity in rats with SCI by inhibiting activated microglia.
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Affiliation(s)
- Suk-Chan Hahm
- Department of Physical Therapy, Korea University College of Health Science, Seoul, Korea
- Rehabilitation Science Program, Department of Health Science, Graduate School, Korea University, Seoul, Korea
- BK21+ Program in Embodiment, Health-Society Interaction, Department of Public Health Science, Graduate School, Korea University, Seoul, Korea
| | - Young Wook Yoon
- Neuroscience Research Institute and Department of Physiology, Korea University College of Medicine, Seoul, Korea
| | - Junesun Kim
- Department of Physical Therapy, Korea University College of Health Science, Seoul, Korea
- Rehabilitation Science Program, Department of Health Science, Graduate School, Korea University, Seoul, Korea
- BK21+ Program in Embodiment, Health-Society Interaction, Department of Public Health Science, Graduate School, Korea University, Seoul, Korea
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Strain GM, Waldrop RD. Temperature and vascular volume effects on gastric ulcerogenesis after cord transection. Dig Dis Sci 2005; 50:2037-42. [PMID: 16240212 DOI: 10.1007/s10620-005-3004-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Accepted: 02/17/2005] [Indexed: 12/09/2022]
Abstract
Gastric ulcers are an important cause of morbidity and mortality in the critically ill, especially those with CNS injury. We used cervical spinal cord transection (CCT) in the rat to model these ulcers and examined the effect of core body temperature and vascular volume on gastric ulcerogenesis. Hypothermia significantly increased ulcerogenesis compared to euthermia, while maintained euthermia produced ulcer indices not different from sham surgery. Hypovolemia (10% blood volume withdrawal) significantly increased ulcerogenesis compared to hypervolemia (10% of blood volume crystalloid infusion) or sham surgery. These results support crystalloid infusion and maintenance of core body temperature in the clinical setting.
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Affiliation(s)
- George M Strain
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
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Kato K, Murai I, Asai S, Takahashi Y, Nagata T, Komuro S, Mizuno S, Iwasaki A, Ishikawa K, Arakawa Y. Circadian rhythm of melatonin and prostaglandin in modulation of stress-induced gastric mucosal lesions in rats. Aliment Pharmacol Ther 2002; 16 Suppl 2:29-34. [PMID: 11966521 DOI: 10.1046/j.1365-2036.16.s2.11.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND We previously demonstrated the circadian variation of water-immersion restraint stress (WRS)-induced gastric mucosal lesions in rats. AIM To investigate the roles of melatonin and prostaglandin in the gastric mucosa in circadian modulation of WRS. METHODS Fasted rats were subjected to 4-h WRS during both the diurnal and nocturnal phases of a light/dark cycle. Mucosal lesions, serum melatonin concentrations, mucosal generation of prostaglandin E2 (PGE2) and mucosal gene expressions of cyclooxygenase (COX)-1 and -2 were evaluated. RESULTS Lesion area after 4-h stress during the dark phase was significantly smaller than that in light-phase controls. Serum melatonin concentration in control rats during the light phase was significantly increased 4 h after WRS, but PGE2 generation was decreased by 48% as compared to that in intact mucosa before stress. In the dark phase, melatonin concentration after 4-h WRS was significantly depressed as compared with the control level at the corresponding time. PGE2 concentrations after 4-h WRS in the dark phase were not decreased compared with the control level at the corresponding time, although PGE2 level was significantly lower than that in light-phase controls. Expression of COX-1 and COX-2 mRNA was detected after exposure to stress in both the light and dark phases. CONCLUSION These results suggest that circadian rhythm has an important role in the formation of stress-induced gastric mucosal lesions in rats. The circadian rhythm of melatonin responses and PGE2 generation may contribute to nocturnal/diurnal rhythmicity of gastric mucosal defences between day and night.
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Affiliation(s)
- K Kato
- Third Department of Internal Medicine, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan.
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Waldrop RD, Strain GM. Autonomic regulation of gastric ulcerogenesis after cervical cord transection in the rat. Acad Emerg Med 1998; 5:230-3. [PMID: 9523931 DOI: 10.1111/j.1553-2712.1998.tb02618.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To examine the role of anticholinergic and sympathomimetic drugs in preventing gastric ulcerogenesis after cervical cord transection (CCT) in the rat. METHODS A randomized, prospective, interventional trial was performed comparing pirenzepine (muscarinic type I receptor antagonist) and ephedrine (nonspecific sympathomimetic) in the prevention of gastric ulcerogenesis after CCT in the rat. After isoflurane-induced general anesthesia, group 1 (n = 12) received sham CCT with no pretreatment, group 2 received CCT with no pretreatment, group 3 received CCT with pirenzepine pretreatment (0.01/mg/kg IP), and group 4 received CCT with ephedrine pretreatment (3 mg/kg IP). Six hours after intervention, all the rats were euthanized with isoflurane, stomachs were dissected, and a gastric ulcer index was determined. RESULTS The mean (+/- SD) ulcer index was 0.08 +/- 0.1 for group 1, 2.33 +/- 0.5 for group 2 (p = 0.01), 0.41 +/- 0.7 for group 3 (p = 0.037 compared with group 2), and 0.75 +/- 0.7 for group 4 (p = 0.0005 compared with group 2). Groups 3 and 4 were not significantly different from each other (p = 0.30). CONCLUSIONS Gastric ulcerogenesis after CCT in the rat is decreased by anticholinergic and sympathomimetic drug pretreatment.
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Affiliation(s)
- R D Waldrop
- Department of Emergency Medicine, Earl K. Long Medical Center, Baton Rouge, LA 70805, USA.
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Abstract
BACKGROUND Fasting during the month of Ramadan provides researchers with a good opportunity to study experimental hunger. METHODS The case histories of patients brought to Ankara Numune Hospital and hospitalized there because of peptic ulcer complaints during the period 1987-92 were retrospectively studied. RESULTS The ratio of peptic ulcer complications was in all the years of the study higher during Ramadan than during the periods before Ramadan (0.05 > p > 0.01) and after Ramadan (0.1 > p > 0.05). Female patients tended to develop more haemorrhage and perforations during Ramadan. In the peptic ulcer perforation group the average age of women was significantly higher during Ramadan, whereas it was significantly lower in men. CONCLUSIONS A type of partial hunger during Ramadan increased peptic ulcer complications.
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Affiliation(s)
- O Dönderici
- Second and Third Internal Disease Clinics, Ankara Numune Hospital, Turkey
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Larsen KR, Moore JG, Dayton MT, Yu Z. Circadian rhythm in aspirin (ASA)-induced injury to the stomach of the fasted rat. Dig Dis Sci 1993; 38:1435-40. [PMID: 8344098 DOI: 10.1007/bf01308600] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Circadian rhythms exist in several gastric parameters affecting ulcerogenesis. This study investigated possible circadian rhythmicity in observed aspirin (ASA)-induced gastric lesions in the rat. In five experiments 183 rats were studied at 14 time points over a 24-hr period. Rats were adapted for three weeks on a 12-hr light schedule, fasted 18 hr, then given oral acidified ASA. One hour later, the rats were sacrificed, the stomachs were removed, stretched flat, photographed, scanned, and measured for percent area of gross lesions in the gastric corpus by computer planimetry. Cosinor rhythmometric analysis showed a significant (P < 0.001) rhythm. Mean of rhythm (MESOR) was 5.60 +/- 0.25% of total corpus. Amplitude was 25.89 +/- 6.07% of MESOR. Peak time (acrophase) was 1909 +/- 0101 hr after lights on. Thus, gastric vulnerability to ASA injury exhibited circadian rhythmicity with peak injury during the dark period in this species.
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Affiliation(s)
- K R Larsen
- Department of Medicine, Salt Lake Veterans Affairs Medical Center, Salt Lake City 84148
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Yi I, Bays ME, Stephan FK. Stress ulcers in rats: the role of food intake, body weight, and time of day. Physiol Behav 1993; 54:375-81. [PMID: 8372135 DOI: 10.1016/0031-9384(93)90126-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Rats were housed in activity wheels (n = 32) or in hanging cages (n = 32) for 2 weeks. Food intake of rats in hanging cages was curtailed to match body weight to that of the activity group. All rats then received 6 g of food at one of four different times of day (n = 8, each mealtime) for 4 consecutive days and were sacrificed 24 h after the last meal. Twenty-three rats in the activity group and 13 rats in the hanging cage group had ulcers in the glandular portion of the stomach. Ulcers were significantly larger and more numerous in the activity group, and activity levels were highly correlated with area of ulceration. In both groups, terminal body weight was also significantly correlated with area of ulceration. No statistically reliable mealtime effects were observed because of large within-group variability. Because many rats in hanging cages developed ulcers in the absence of wheel running, the results suggest that restricted food supply and loss of body weight are initiating factors in ulcer formation, while excessive wheel running contributes to the severity of ulcerations in the glandular stomach.
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Affiliation(s)
- I Yi
- Department of Psychology, Florida State University, Tallahassee 32310-1051
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Moore JG, Mitchell MD, Larsen KR, Dayton MT. Circadian rhythm in prostacyclin activity in gastric tissue of the fasting rat. Am J Surg 1992; 163:19-22. [PMID: 1733369 DOI: 10.1016/0002-9610(92)90246-n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gastroduodenal ulcer disease may result from the desynchronization of the circadian rhythms of gastric protective and destructive factors. The purpose of this study was to evaluate whether gastric tissue 6-keto prostaglandin F1 alpha (PGF1 alpha), a catabolic derivative of the putative protective factor prostacyclin, is produced in a circadian fashion in the rat model. Forty-eight male Sprague-Dawley rats were acclimatized in sound-attenuated, lightproof chambers for 3 weeks on a 12:12 hour light/dark entrainment schedule. After an 18-hour fast, six rats were killed at each of eight sampling times. The stomachs were exposed, removed, and assayed for total 6-keto PGF1 alpha content by radioimmunoassay. Cosinor analysis of the data showed significant (p = 0.0262) circadian rhythmicity in 6-keto PGF1 alpha content with an acrophase (peak time) value of 0503 HALO (hours after lights on) or in the middle of the lights-on inactive period for the rats. Hypothetically, the circadian rhythm in some gastric protective factors may render the gastric mucosa vulnerable to injury in a circadian fashion.
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Affiliation(s)
- J G Moore
- Salt Lake City Veterans Administration Medical Center, Department of Medicine, Utah 84148
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Larsen KR, Moore JG, Dayton MT. Circadian rhythms of gastric mucus efflux and residual mucus gel in the fasting rat stomach. Dig Dis Sci 1991; 36:1550-5. [PMID: 1935492 DOI: 10.1007/bf01296396] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We hypothesized that two putative gastric protective factors, mucus efflux and residual mucus gel content, would manifest circadian rhythms, as reported in several other gastric functions. Rats were adapted for three weeks on a 12-hr light schedule, fasted 18-hr and studied at 3-hr intervals. Under anesthesia, the stomachs were cannulated and filled with test solution. Thirty minutes later, they were drained and the luminal fluid was analyzed for mucus content by Alcian blue binding. Residual mucus gel was determined by direct injection of dye into the lumen. Alcian blue binding of rat mucus was expressed as equivalent milligrams of porcine mucin. Both parameters showed a significant (P less than 0.001) circadian rhythm. Mucus efflux peaked at 5:03 +/- 0:52 HALO (hours after lights on), and residual mucus at 6:00 +/- 0.46 HALO. Thus, the interplay of circadian rhythms in aggressive and defensive gastric mucosal functions is supported.
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Affiliation(s)
- K R Larsen
- Department of Medicine, Salt Lake Veterans Affairs Medical Center, Utah 84148
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Larsen KR, Dayton MT, Moore JG. Circadian rhythm in gastric mucosal blood flow in fasting rat stomach. J Surg Res 1991; 51:275-80. [PMID: 1921365 DOI: 10.1016/0022-4804(91)90107-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Circadian rhythms are present in several gastric functions including acid secretion and emptying rates. We hypothesize that aggressive and defensive factors in the gastric mucosa follow similar circadian rhythms. The purpose of this study was to determine if gastric mucosal blood flow, a known defensive factor, manifests a circadian rhythm in fasting rats. Ninety-six male Sprague-Dawley rats were light-adapted in isolation chambers for 3 weeks prior to the study. Half the rats experienced light from 6:00 AM to 6:00 PM, the other half from 6:00 PM to 6:00 AM. After an 18-hr fast, 12 rats were studied at each of eight sampling times: 0100, 0400, 0700, 1000, 1300, 1600, 1900, and 2200 hr after lights on (HALO). After anesthesia and laparotomy, the stomachs were opened along the anterior surface, gently stretched with mucosal surface upmost, and trapped between two lucite rings, with blood supply intact. Mucosal blood flow (ml/min/100 g) was measured in the forestomach, corpus, and antrum with a laser Doppler flowmeter (TSI Laserflo BPM 403). Cosinor analysis showed a significant (P less than 0.01) circadian rhythm in gastric mucosal blood flow within the corpus and antrum, but not in the forestomach. Peak time for corpus blood flow was 21:45 +/- 0:56 HALO (3:45 AM). In the antrum it was 0:51 +/- 1:08 HALO (6:51 AM). These results support the hypothesis that circadian rhythms in mucosal defensive functions are an integral part of normal gastric physiology.
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Affiliation(s)
- K R Larsen
- Department of Medicine, Salt Lake Veterans Affairs Medical Center, Utah 84148
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