1
|
Ozaki K, Yamano S, Matsuura T, Narama I. Insulin-ameliorated peripheral motor neuropathy in spontaneously diabetic WBN/Kob rats. J Vet Med Sci 2013; 75:1323-8. [PMID: 23748976 PMCID: PMC3942929 DOI: 10.1292/jvms.13-0184] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Rodent models of diabetes develop a slowing of nerve conduction velocity and mild axonal
atrophy, but generally lack overt degenerative neuropathy. Spontaneously diabetic Wistar
Bonn Kobori (WBN/Kob) rats develop severe diabetic peripheral motor neuropathy with a
slowing of nerve conduction velocity. We examined the effect of glycemic control, using
insulin implant, on neuropathic changes in these rats. Animals were divided into 2 groups:
WBN group (spontaneously occurring diabetes rats) and WBN + insulin group (spontaneously
occurring diabetes rats treated with insulin implants until 90 weeks of age). Conduction
velocity was measured in sciatic–tibial motor nerves. These nerves also underwent
qualitative and quantitative histomorphologic analysis. Mild to severe hyperglycemia
(>200 mg/dl) and glycosuria (>100 mg/dl) were
observed in the WBN group. In contrast, the blood glucose level of the WBN + insulin group
fluctuated between normoglycemia (<200 mg/dl) and hyperglycemia.
Conduction velocity significantly decreased in WBN group compared with WBN + insulin
group. Morphologic analysis of the sciatic and tibial nerves of WBN group showed severe
changes, including axonal degeneration, myelin distention, endoneurial fibrosis and
microangiopathy. Insulin treatment corrected these changes without microangiopathy. These
results suggest that insulin could decrease axonal atrophy and myelin distension of
peripheral nerve in diabetic WBN/Kob rats. Observation of WBN/Kob rats revealed changes of
axon, myelin and capillary caused by diabetes, thus indicating that this animal is a
suitable model for investigating diabetic peripheral neuropathy.
Collapse
Affiliation(s)
- Kiyokazu Ozaki
- Department of Pathology, Setsunan University, 45-1 Nagaotohge-cho, Hirakata, Osaka 573-0101, Japan
| | | | | | | |
Collapse
|
2
|
Oliveira FS, Nessler RA, Castania JA, Salgado HC, Fazan VPS. Ultrastructural and morphometric alterations in the aortic depressor nerve of rats due to long term experimental diabetes: effects of insulin treatment. Brain Res 2012; 1491:197-203. [PMID: 23123208 DOI: 10.1016/j.brainres.2012.10.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/17/2012] [Accepted: 10/26/2012] [Indexed: 10/27/2022]
Abstract
Most of the reports about an altered baroreflex attribute this condition to the diabetic efferent neuropathy of the aortic depressor nerve (ADN) (afferent arm of the baroreflex less explored). We evaluated the ADN ultrastructural alterations caused by long term experimental diabetes and the effects of insulin treatment. Wistar rats (N=14) received a single intravenous injection of streptozotocin (40 mg/kg) 12 weeks before the experiment. Control animals (N=9) received vehicle (citrate buffer). Insulin treated animals (N=8) received a single subcutaneous injection of insulin daily. Under pentobarbital anesthesia the ADNs were isolated and had their spontaneous activity recorded. Afterwards, proximal and distal segments of the nerves were prepared for transmission electron microscopy study. Morphometry of the unmyelinated fibers was carried out with the aid of computer software. ADN of the diabetic animals showed axonal atrophy for myelinated fibers, with more pronounced alterations of the myelin sheath, such as myelin infolding and out folding, presence of myelin balls and very thin myelin sheath in relation to the axonal size, particularly for the small myelinated fibers becoming evident. No differences were observed in myelinated fiber number and their density, as well as on the fascicular area. Unmyelinated fiber number was significantly larger in the diabetic group while fiber diameter was significantly smaller compared to control. This result suggests axonal atrophy or, if associated to the larger number of fibers present in this group, could indicate fiber sprouting. These alterations were more evident in the distal segments of the nerves and were moderated by insulin treatment.
Collapse
Affiliation(s)
- Fabrício S Oliveira
- Veterinary Medicine, Maringá State University-Umuarama Campus, Umuarama, Paraná, Brazil
| | | | | | | | | |
Collapse
|
3
|
Glucose metabolism in the idiopathic blepharoptosis: Utility of the Oral Glucose Tolerance Test (OGTT) and of the Insulin Resistance Index. J Neurol Sci 2009; 284:24-8. [DOI: 10.1016/j.jns.2009.03.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 03/01/2009] [Accepted: 03/13/2009] [Indexed: 11/22/2022]
|
4
|
Abstract
Diabetes mellitus is associated with many different neuropathic syndromes, ranging from a mild sensory disturbance as can be seen in a diabetic sensorimotor polyneuropathy, to the debilitating pain and weakness of a diabetic lumbosacral radiculoplexus neuropathy. The etiology of these syndromes has been studied extensively, and may vary among metabolic, compressive, and immunological bases for the different disorders, as well as mechanisms yet to be discovered. Many of these disorders of nerve appear to be separate conditions with different underlying mechanisms, and some are caused directly by diabetes mellitus, whereas others are associated with it but not caused by hyperglycemia. This article discusses a number of the more common disorders of nerve found with diabetes mellitus. It discusses the symmetrical neuropathies, particularly generalized diabetic polyneuropathy, and then the focal or asymmetrical types of diabetes-associated neuropathy.
Collapse
Affiliation(s)
- Jennifer A Tracy
- Peripheral Neuropathy Research Laboratory, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | | |
Collapse
|
5
|
Jamali R, Mohseni S. Hypoglycaemia causes degeneration of large myelinated nerve fibres in the vagus nerve of insulin-treated diabetic BB/Wor rats. Acta Neuropathol 2005; 109:198-206. [PMID: 15549329 DOI: 10.1007/s00401-004-0932-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2004] [Revised: 08/25/2004] [Accepted: 09/06/2004] [Indexed: 10/26/2022]
Abstract
The aim of this study was to find out whether dysglycaemia causes neuropathy in the vagus nerve of insulin-treated diabetic BB/Wor rats. Specimens were collected from the left vagus nerve proximal and distal to the level of recurrent laryngeal branch and from the recurrent branch itself in control rats and diabetic BB/Wor rats subjected to hyper- or hypoglycaemia. Myelinated and unmyelinated axons were counted and myelinated axon diameters were measured by electron microscopy. In controls, the vagus nerve proximal to the recurrent branch exhibited three regions in terms of fibre composition: part A was mainly composed of large myelinated axons, part B contained small myelinated and unmyelinated axons, and part C contained mainly unmyelinated axons. The distal level resembled part C at the proximal level and the recurrent branch resembled parts A and B. In hyperglycaemic rats, a normal picture was found at the proximal and distal levels of the vagus nerve and in the recurrent branch. In hypoglycaemic rats, signs of past and ongoing degeneration and regeneration of large myelinated axons were found at the proximal and distal levels and in the recurrent branch. We conclude that hypoglycaemia elicits degenerative alterations in large myelinated axons in the vagus and recurrent laryngeal nerves in diabetic BB/Wor rats. The absence of signs of neuropathy in unmyelinated and small myelinated axons suggests that the sensory and autonomic components of the nerve are less affected. In contrast, the hyperglycaemic rats examined here did not show obvious degenerative alterations.
Collapse
Affiliation(s)
- Reza Jamali
- Division of Cell Biology, Department of Biomedicine and Surgery and Diabetic Research Centre, Faculty of Health Sciences, Linköping University, 581 85 , Linköping, Sweden
| | | |
Collapse
|
6
|
Abstract
In this article we will review the clinical signs and symptoms of diabetic somatic polyneuropathy (DPN), its prevalence and clinical management. Staging and classification of DPN will be exemplified by various staging paradigms of varied sophistication. The results of therapeutic clinical trials will be summarized. The pathogenesis of diabetic neuropathy reviews an extremely complex issue that is still not fully understood. Various recent advances in the understanding of the disease will be discussed, particularly with respect to the differences between neuropathy in the two major types of diabetes. The neuropathology and natural history of diabetic neuropathy will be discussed pointing out the heterogeneities of the disease. Finally, the various prospective therapeutic avenues will be dealt with and discussed.
Collapse
Affiliation(s)
- K Sugimoto
- Department of Pathology, Wayne State University, School of Medicine and Detroit Medical Center, Detroit, MI 48201, USA
| | | | | |
Collapse
|
7
|
Tabata H. Peripheral neuropathy in B6C3F1 mice and SD rats induced by chronic intermittent insulin hypoglycemia. Drug Chem Toxicol 2000; 23:485-96. [PMID: 10959549 DOI: 10.1081/dct-100100130] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The effects of sustained insulin-induced hypoglycemia on peripheral nerves were examined in 9-10-week old female B6C3F1 mice and 9-10-week old female SD rats. Insulin was administered via osmotic minipumps at a dose of 81 IU/kg/day for 2 consecutive weeks. Mice and rats treated with this high insulin dose showed marked hypoglycemia, resulting in half the normal blood glucose level, hypothermia, impaired motor nerve conduction velocity, and an increased incidence of peripheral nerve lesions, consisting of nerve fiber degeneration characterized by irregular myelin sheaths and axonal atrophy.
Collapse
Affiliation(s)
- H Tabata
- Safety Research Laboratories, Yamanouchi Pharmaceutical Co., Ltd., Tokyo, Japan.
| |
Collapse
|
8
|
Di Paolo A, Danesi R, Innocenti F, Bocci G, Nardini D, Fogli S, Pollina L, Rossi B, Del Tacca M. Chronic administration of suramin induces neurotoxicity in rats. J Neurol Sci 1997; 152:125-31. [PMID: 9415531 DOI: 10.1016/s0022-510x(97)00185-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the present study, the ability of suramin 18 mg/kg i.p. twice a week to induce chronic neurotoxicity in rats was investigated. After 20 weeks of suramin treatment, morphological analysis of nerve fibers demonstrated that 57.7+/-3.2% of them presented vesicular disruption of myelin sheaths; their thickness was 0.23+/-0.07 microm in suramin-treated rats with respect to 0.43+/-0.07 microm of controls (P<0.05). To investigate the interaction between suramin and nerve tissue, the binding of the drug to partially purified myelin P0 protein obtained from sciatic nerves was analysed. The percentage of suramin bound to rat myelin P0 protein was 94.0+/-9.5%; this value was decreased to 55.0+/-7.6% when heparan sulfate was added to the myelin protein suspension before suramin. The analysis of tissue drug concentrations at 5, 10 and 20 weeks of treatment showed that suramin accumulated into the sciatic nerve in a time-dependent fashion (130.8+/-18.1, 219.7+/-17.1 and 449.3+/-15.6 microg/g of tissue, respectively). In conclusion, suramin induces a chronic peripheral neurotoxicity in rats characterized by myelin damage and high tissue levels of the drug. The high affinity of suramin for partially purified myelin P0 protein suggests a possible mechanism for drug-induced toxicity.
Collapse
Affiliation(s)
- A Di Paolo
- Superior School of University Studies and Doctoral Research S. Anna, Pisa, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Nickander KK, McPhee BR, Low PA, Tritschler H. Alpha-lipoic acid: antioxidant potency against lipid peroxidation of neural tissues in vitro and implications for diabetic neuropathy. Free Radic Biol Med 1996; 21:631-9. [PMID: 8891666 DOI: 10.1016/0891-5849(96)00172-4] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Nerve lipid peroxidation is increased in experimental diabetic neuropathy, and alpha-lipoic acid will prevent the deficits in nerve blood flow, oxidative stress, and distal sensory conduction. Because these alterations can occur by mechanisms other than augmenting lipid peroxidation in vivo, and because both pro-oxidant and antioxidant effects of the agent have been reported, we undertook studies of in vitro lipid peroxidation of brain and sciatic nerve using an in vitro lipid peroxidation model with an ascorbate-iron-EDTA system. We evaluated the effectiveness of the R(+)-, S(-)-enantiomers, and racemate of alpha-lipoic acid in reducing thiobarbituric acid reactive substances (TBARS) generation in rat brain and sciatic nerve. Studies were also done in an incubation medium containing 20 mM glucose, which increased lipid peroxidation up to fourfold. A dose-dependent and statistically significant reduction in lipid peroxidation was seen with both tissues with similar potencies for both enantiomers. This effect was unassociated with any reduction in the loss of alpha-tocopherol.
Collapse
Affiliation(s)
- K K Nickander
- Department of Neurology, Mayo Foundation, Rochester, MN 55905, USA
| | | | | | | |
Collapse
|
10
|
Yagihashi S. Pathology and pathogenetic mechanisms of diabetic neuropathy. DIABETES/METABOLISM REVIEWS 1995; 11:193-225. [PMID: 8536541 DOI: 10.1002/dmr.5610110304] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- S Yagihashi
- Department of Pathology, Hirosaki University School of Medicine, Japan
| |
Collapse
|
11
|
Weis J, Dimpfel W, Schröder JM. Nerve conduction changes and fine structural alterations of extra- and intrafusal muscle and nerve fibers in streptozotocin diabetic rats. Muscle Nerve 1995; 18:175-84. [PMID: 7823975 DOI: 10.1002/mus.880180205] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Streptozotocin-induced diabetes mellitus is known to cause a reduction of both conduction velocity and axon caliber in sciatic nerves and also a decrease in muscle fiber size. The present study investigates whether the distal parts of the peripheral nervous system, including extra- and intrafusal muscle fibers, are more severely affected than the proximal segments in the diabetic state. Proximal and distal sensory nerve conduction velocities were monitored during a period of 3 months in rats rendered diabetic by injection of streptozotocin. Segments of the sciatic and ventral coccygeal nerves, and of the biceps femoris and lumbrical muscles, were studied by light and electron microscopy, including morphometric analysis. In contrast to previous studies, daily suboptimal insulin injections were given to prevent acute metabolic complications. Sensory conduction velocity in the ventral coccygeal nerve was significantly (P < 0.05) decreased in the diabetic rats compared to controls. Proximal and distal nerve segments were equally affected. Mean cross-sectional axon area of the sciatic nerve was moderately, but significantly (P < 0.05), smaller in insulin-treated diabetic rats than in controls. In both the sciatic nerve and the terminal, intrafusal nerve segments, occasional axons showed moderate dystrophic changes. Fibers of the intrafusal nerve segments appeared to be equally affected compared to the fibers in the sciatic nerve, although no quantitative comparison was made. The increase of small caliber skeletal muscle fibers in experimental streptozotocin-induced diabetes was confirmed. These findings indicate that proximal and distal segments of peripheral nerves are affected equally in the early stages of experimental diabetic neuropathy.
Collapse
Affiliation(s)
- J Weis
- Institute of Neuropathology, Technical University, Aachen, Germany
| | | | | |
Collapse
|
12
|
Novotny MV, Yancey MF, Stuart R, Wiesler D, Peterson RG. Inhibition of glycolytic enzymes by endogenous aldehydes: a possible relation to diabetic neuropathies. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1226:145-50. [PMID: 8204661 DOI: 10.1016/0925-4439(94)90022-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Endogenous saturated and unsaturated aldehydes were found in significant elevations in serum of diabetic humans and rats. These compounds, originating from the lipid peroxidation processes, are shown here to be potent inhibitors of the glycolytic enzymes, phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. The inhibition process is non-competitive and progressive. The aldehyde mixture, when supplemented to the standard rat diet at 1/100 ratio, caused nerve damage that is reminiscent of diabetic polyneuropathies.
Collapse
Affiliation(s)
- M V Novotny
- Department of Chemistry, Indiana University, Bloomington 47405
| | | | | | | | | |
Collapse
|
13
|
Klueber KM, Feczko JD. Ultrastructural, histochemical, and morphometric analysis of skeletal muscle in a murine model of type I diabetes. Anat Rec (Hoboken) 1994; 239:18-34. [PMID: 8037375 DOI: 10.1002/ar.1092390104] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Since peripheral nerves are damaged in diabetes mellitus, morphological changes occur within the diabetic muscle in response to the diabetic neuropathy. The aim of this study was to examine the extensor digitorum longus (EDL) from a 42-day streptozotocin-induced diabetic Swiss Webster mouse (STZ) and compare the muscle morphology and histochemistry to age-matched, nondiabetic controls. METHODS The EDL was evaluated using electron microscopy in order to investigate the morphological integrity of the myofibers and neuromuscular junctions. Histochemical analysis was completed using the myofibrillar CA(++)-ATPase reaction of Doriguzzi et al. (1983. Histochemistry, 79:289-294) for use in computer-assisted morphometric analysis of fiber size using Bioquant System 4 software. RESULTS Ultrastructural analysis of the diabetic EDL (N = 5, 225 myofibers/animal) showed a significant number of abnormal myofibers, exhibiting various degrees of degeneration, signs of denervation, and necrosis. The STZ myofibers exhibited excessive lipid accumulations and abnormal mitochondrial arrangements. Histochemical analysis of the STZ EDL revealed a significant shift in fiber type profile (53.6% type 2A and 46.4% type 2B- STZ myofibers; 47.5% type 2A, 52.5% type 2B nondiabetic controls). Morphometric analysis of myofiber size by fiber type (200 myofibers/muscle/fiber type) indicated a significant decrease in myofiber size for both type 2A and type 2B fibers in the STZ diabetic mouse. CONCLUSION The degeneration and necrosis of myofibers concomitant with the sever atrophy of both the type 2A and 2B myofibers in the STZ muscle could account for the functional alterations seen in diabetic muscle.
Collapse
Affiliation(s)
- K M Klueber
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Kentucky 40292
| | | |
Collapse
|
14
|
Klueber KM, Porta DJ. Cytoarchitecture of diabetic myopathy during the pathogenesis of the disease: Fast versus slow muscle. Clin Anat 1994. [DOI: 10.1002/ca.980070606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
15
|
Britland ST, von Zimmermann O, Sharma AK, Bretzel RG, Federlin K. The effect of pancreatic islet transplantation on experimental diabetic neuropathy. J Neurol Sci 1991; 105:168-74. [PMID: 1757793 DOI: 10.1016/0022-510x(91)90141-s] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Quantitative light and electronmicroscopical morphometric techniques were used to determine the effect of pancreatic islet transplantation on experimental diabetic neuropathy. Groups of STZ-diabetic rats were given islet transplants at 3 weeks after diabetes onset (prevention) and at 6 months after diabetes onset (reversal). Comparisons were made with onset controls, age-matched non-diabetic controls and untreated diabetic controls 6 months later (n = 8 for all groups). Euglycaemia and normal levels of glycosylated haemoglobin were achieved in both groups of diabetics after islet transplantation. Loss of body weight in diabetic animals was prevented by early islet transplantation, but was only partially reversed following delayed islet transplantation. Normal growth of myelinated fibres and axons during development was retarded in untreated diabetics, but was normal in rats given islet transplants soon after the onset of diabetes (cross-sectional perimeter and area). Diabetics transplanted with islets after a delay had myelinated fibres and axons with diminished calibre. Teased fibre preparations of nerves from diabetics which had received islet transplants showed no excess of abnormalities. This study has shown that the development of certain structural abnormalities of peripheral nerve fibres is prevented in diabetic rats which receive transplants of islets of Langerhans soon after the onset of diabetes. However, once established abnormal fibre morphology can not be completely ameliorated merely by achieving and sustaining euglycaemia through delayed islet transplantation.
Collapse
|
16
|
Abstract
The duration and severity of hypoglycemia needed to induce neuropathy is not known. To test these variables, the percentage of teased fibers of peroneal and tibial nerves showing graded pathologic abnormalities was estimated in groups of rats that had been made hypoglycemic for various times and severities one week earlier. The techniques used maintained core temperature, pO2, pCO2, and hematocrit within physiologic limits. A control group was anesthetized and mechanically ventilated but insulin was not given. A second control group underwent no experimental manipulation. Life could not be sustained with hypoglycemia below 1 mmol/l. In 23 rats that were hypoglycemic (1.4 +/- 0.2 mmol/l, mean +/- S.E.M.) for various times less than 11 h, the frequency of axonal degeneration of teased myelinated fibers (0%-1%) was not different than in controls. In 9 young rats that were hypoglycemic (1.4 +/- 0.0 mmol/l) for various times of 12 or more hours, the frequency of fiber degeneration was significantly higher than in controls (P less than 0.01) and increased to as high as 26%. By contrast, in 5 older rats that were hypoglycemic (1.5 +/- 0.1 mmol/l) for various times of 12 or more hours, the frequency of degeneration was not different from that of controls. Both duration and severity of hypoglycemia are risk factors for fiber degeneration. The peripheral nerves are more vulnerable to prolonged severe hypoglycemia in younger rats than in older rats.
Collapse
Affiliation(s)
- S Yasaki
- Peripheral Nerve Center, Mayo Clinic, Rochester, MN 55905
| | | |
Collapse
|
17
|
Klueber KM, Feczko JD, Schmidt G, Watkins JB. Skeletal muscle in the diabetic mouse: histochemical and morphometric analysis. Anat Rec (Hoboken) 1989; 225:41-5. [PMID: 2774212 DOI: 10.1002/ar.1092250107] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Despite the extensive literature concerning the neuropathy associated with diabetes, only limited information describes changes in the associated muscle. The objective of this study was to evaluate the histochemical and morphometric characteristics of diabetic muscle in the C57BL/KsJ db-m strain of mouse. The histochemical analysis of myofiber type for the diabetic mouse revealed that the extensor digitorum longus muscle consisted of 53.1% type 2a, 46.0% type 2b, and 0.9% type 1 myofibers, a significant shift from the percentages found in the nondiabetic litter mates (44.4% type 2a, 55.6% type 2b, no type 1). Computer-assisted morphometric analysis of myofiber size by fiber type indicated a significant difference in myofiber size for the type 2b fibers in muscles from diabetic mice. Similarly, there was a shift in the fiber size distribution to include a greater number of small type 2b myofibers when compared to controls. Skeletal muscle from diabetic mice exhibited a significant change in the percentage of fiber types, with an increase in the number of type 2a fibers, a fiber type grouping that implies possible denervation and reinnervation, and a decrease in myofiber size. These findings may explain why some diabetic patients complain of muscle weakness.
Collapse
Affiliation(s)
- K M Klueber
- Medical Sciences Program, Indiana University, Bloomington
| | | | | | | |
Collapse
|
18
|
de Freitas MR, Chimelli L, Nascimento OJ, Barbosa GM. [Hypoglycemic polyneuropathy: report of a case with insulinoma]. ARQUIVOS DE NEURO-PSIQUIATRIA 1989; 47:235-40. [PMID: 2556983 DOI: 10.1590/s0004-282x1989000200017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A case of a young man who presented symptoms and clinical signs of polyneuropathy that occurred in connection with recurrent hypoglycemic episodes is reported. The hypoglycemia was probably caused by a pancreatic islet tumor. There were symmetric weakness and wasting of hands and feet, absent tendon reflexes and 'glove and stocking' loss of sensation. Electromyographic studies showed denervation potentials with slight reduction of nerve conduction velocities. Sural nerve biopsy studied by optic and electronic microscopy showed axonal degeneration without signs of demyelination or remyelination. There are only 30 similar cases reported in the literature. According to experimental findings, the authors believe that glucopenia is the mechanism responsible for the development of the neuropathy, and that at present time there is no evidence for a direct insulin effect.
Collapse
Affiliation(s)
- M R de Freitas
- Departamentos de Medicina Clínica e de Patologia, Faculdade de Medicina, Universidade Federal Fluminense
| | | | | | | |
Collapse
|
19
|
Abstract
Functional and structural neuropathy was examined in hyperglycemic (diabetic) BB rats maintained on small maintenance doses of insulin, hyperglycemic BB rats receiving no insulin, and BB rats in whom hypoglycemia was induced by the administration of excessive insulin doses. The data were compared with those of non-diabetic age- and sex-matched BB rats. Functional deficits and structural abnormalities were comparable in diabetic rats with and without insulin supplementation, suggesting that the generally necessary insulin dosing in this model does not per se account for the neuropathy. Hypoglycemic neuropathy was characterized by slowing of nerve conduction velocity, marked loss of anterior horn motoneurons and Wallerian degeneration, as well as loss of large myelinated fibers, suggesting a neuropathy involving predominantly motoneurons. Diabetic neuropathy was not associated with nerve cell loss but showed marked axonal atrophy involving predominantly sensory fibers. Thus, diabetic and hypoglycemic neuropathies are two distinguishable entities under strict experimental conditions, but may overlap in human diabetic subjects in whom tight insulin control is desirable.
Collapse
Affiliation(s)
- A A Sima
- Neuropathology Research Laboratory, Department of Pathology, University of Manitoba, Winnipeg, Canada
| | | | | |
Collapse
|
20
|
Larsen JR, Sidenius P. Slow axonal transport of structural polypeptides in rat, early changes in streptozocin diabetes, and effect of insulin treatment. J Neurochem 1989; 52:390-401. [PMID: 2463334 DOI: 10.1111/j.1471-4159.1989.tb09134.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The synthesis and transport of slowly transported polypeptides in sciatic nerves of rats was investigated by [35S]methionine pulse labeling and gel electrophoresis in control, diabetic, and insulin-treated diabetic rats. To detect very early changes diabetes was induced by streptozocin only 5 days prior to the labeling of the dorsal root ganglion cells. Fourteen days were allowed for axonal transport. In this experimental system, the neurofilament triplet is transported at an apparent velocity of 1.1 +/- 0.1 mm/day (mean +/- SD). The actin-related complex, including actin and two polypeptides of 87 kilodaltons and 37 kilodaltons, was transported at a velocity of 2.6 +/- 0.2 mm/day. For alpha- and beta-tubulin we found an apparent transport velocity of 2.2 +/- 0.1 mm/day, placing it between actin and the neurofilament triplet. The diabetic rats had a selective 32% decrease in the amount of the heaviest neurofilament subunit: 0.47 +/- 0.19% of trichloroacetic acid-insoluble radioactivity versus 0.69 +/- 0.17% in controls; 2p less than 0.05. This decrease was associated with a proximal accumulation of the two lighter neurofilament subunits. Insulin treatment of a diabetic group failed to normalize the changes of axonal transport and additional changes suggesting a hypoglycemic injury was observed.
Collapse
Affiliation(s)
- J R Larsen
- Diabetes Research Laboratory, Second University Clinic of Internal Medicine, Aarhus, Denmark
| | | |
Collapse
|
21
|
Abstract
Morphological and electrophysiological observations were made over 4 weeks on 5 groups of 8-week-old male Sprague-Dawley rats. These were comprised of controls, untreated diabetics, and diabetic animals in which sustained hypoglycemia, moderate hypoglycemia, or normoglycemia was induced by continuous subcutaneous insulin infusion (CSII) therapy. Teased fiber studies showed a marked increase in the number of myelinated fibers undergoing axonal degeneration and regeneration in the tibial nerve of severe hypoglycemic and also in moderate hypoglycemic animals but not in controls, untreated diabetic and normoglycemic groups. There was also a significant correlation between episodes of hypoglycemia (less than or equal to 2.0 mmol/l) and the prevalence of axonal degeneration and regeneration in CSII-treated diabetics. Motor nerve conduction velocity was significantly reduced in the moderate and severe hypoglycemic groups and also in untreated diabetic animals when compared with controls. However, it was significantly improved in the normoglycemic group over the untreated diabetic and severe hypoglycemic groups. In conclusion, this study has demonstrated that severe or even mild hypoglycemia produced a detrimental effect on peripheral nerve structure and function in experimental diabetes. Therefore, it may be desirable to avoid even asymptomatic hypoglycemia in the management of diabetes.
Collapse
Affiliation(s)
- C G Potter
- Program in Medical Neurobiology, Indiana University School of Medicine, Indianapolis 46223
| | | | | | | |
Collapse
|
22
|
Feczko JD, Klueber KM. Cytoarchitecture of muscle in a genetic model of murine diabetes. THE AMERICAN JOURNAL OF ANATOMY 1988; 182:224-40. [PMID: 3213821 DOI: 10.1002/aja.1001820304] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Although diabetic neuropathy is well documented, diabetic myopathy is not, except for descriptions of diabetic patients with muscular weakness thought to be due to metabolic changes in the muscle. Muscle and nerve are dependent on each other for normal structure and function; since the peripheral nerve is damaged in diabetes, one would expect concomitant changes in the muscle. This study examines the cytoarchitecture of diabetic muscle. The extensor digitorum longus (EDL) muscles from 165-day-old C57BL/KsJ dbm mice were examined using electron microscopy. Morphological analysis of the diabetic EDL revealed that a significant number of the myofibers, examined within the midbelly region of the muscle, exhibited various degrees of degeneration, signs of denervation, and abnormal lipid stores. Both myoneural junctions and muscle spindles showed significant signs of degeneration, denervation, and abnormal structure. Thus the morphologic changes seen could account for the physiologic changes seen in diabetic muscle.
Collapse
Affiliation(s)
- J D Feczko
- Medical Sciences Program/Anatomy, Indiana University School of Medicine, Bloomington 47405
| | | |
Collapse
|
23
|
Schlosser MJ, Kapeghian JC, Verlangieri AJ. Selected physical and biochemical parameters in the streptozotocin-treated guinea pig: insights into the diabetic guinea pig model. Life Sci 1987; 41:1345-53. [PMID: 2957557 DOI: 10.1016/0024-3205(87)90608-4] [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: 01/03/2023]
Abstract
Since evidence suggests that ascorbic acid deficits may provoke certain diabetic complications, it becomes necessary to develop a diabetic animal model which, like man, is unable to synthesize this vitamin. To this end, the present study monitored the diabetogenic effects of streptozotocin (STZ, 150 mg/kg) in the male guinea pig, a species rarely used in diabetes research. Over a 3-week period, body weight and relative food intake were lower in the STZ group compared to controls. The mean daily water intake and urine volume of the STZ group after 1 week were 175 and 270% of their initial pretreatment values, respectively, while control values were unchanged. The STZ group also exhibited a persistent glycosuria throughout the study. At the end of 3 weeks, aldehyde fuchsin staining of pancreatic beta cell granules (an index of stored insulin) was 58% lower in the STZ group compared to controls. Plasma C-peptide (indicator of insulin secretion) was expressed in human equivalents (mean +/- SEM). C-peptide was reduced in the STZ group (103 +/- 65 pg/ml) compared to controls (549 +/- 96 pg/ml); however, no change in plasma glucose was observed. Plasma ascorbic acid levels also were lower for STZ animals (150 +/- 26 micrograms%) versus controls (410 +/- 28 micrograms%). This study 1) demonstrates a diabetic syndrome in the STZ-treated guinea pig based on a reduced growth rate, beta cell dysfunction, polydipsia, polyuria and glycosuria, and 2) suggests the usefulness of this diabetic model in studies of pathologic mechanisms influenced by ascorbic acid.
Collapse
|
24
|
Abstract
Recent advances in the understanding of the pathogenesis of diabetic neuropathy have been made in six areas. There is support for the notion that a reduction in nerve free myoinositol may be responsible in part for the nerve conduction slowing in diabetic neuropathy. There is further evidence of microvascular abnormalities, including morphometric evidence of multifocal fiber loss and of capillary changes in biopsied sural nerve. There is evidence of endoneurial hypoxia, including the findings of reduced nerve blood flow and endoneurial oxygen tensions in chronic experimental diabetic neuropathy (EDN). The major mechanisms of resistance to ischemic conduction failure (RICF) is the marked increase in nerve energy substrates. Recent studies provide certain insights into clinical characteristics of human diabetic neuropathy (HDN), including the asymmetric pattern of HDN, the paradox between liability to pressure palsies and RICF, and insulin-related acute painful neuropathy. The suggested pathogenetic scheme incorporates the notion that once hypoxia is established, it may start a vicious cycle of further capillary damage and escalating hypoxia.
Collapse
|
25
|
McCallum KN, Sharma AK, Blanchard DS, Stribling D, Mirrlees DJ, Duguid IG, Thomas PK. The effect of continuous subcutaneous insulin infusion therapy on morphological and biochemical abnormalities of peripheral nerves in experimental diabetes. J Neurol Sci 1986; 74:55-67. [PMID: 3522807 DOI: 10.1016/0022-510x(86)90191-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Diabetes mellitus was induced in rats by the administration of streptozotocin and observations have been made over a period of 2 months in 3 groups of animals: controls, untreated diabetics and diabetics treated with continuous subcutaneous insulin infusion (CSII) therapy, using a 14-day Alzet osmotic minipump. Optimal control of day-to-day and 24-h blood glucose levels was achieved in diabetic animals treated with CSII. Body weight and skeletal growth, assessed by measurements of tibial length, were decreased in untreated diabetic rats and were normalized by insulin treatment. The concentrations of glucose, sorbitol and fructose in the nerves of diabetic animals were significantly increased and that of myoinositol significantly decreased; CSII therapy normalized these levels to those of age-matched controls. External myelinated fibre diameter in the tibial nerve was significantly less in untreated diabetic rats as compared with age-matched controls. In the insulin-treated group, fibre diameter significantly increased as compared with untreated diabetics and there was no significant difference between insulin-treated and control animals. Teased fibre preparations from the tibial nerve revealed very few abnormal fibres in all the three groups and no significant difference was detected between any of the groups. Continuous subcutaneous insulin infusion therapy, therefore, corrected biochemical abnormalities and also normalized myelinated fibre diameter in the peripheral nerves of experimental diabetic animals. The paradoxical excess of axonal degeneration that has been reported with conventional insulin treatment was not observed.
Collapse
|
26
|
Berti-Mattera L, Peterson R, Bell M, Eichberg J. Effect of hyperglycemia and its prevention by insulin treatment on the incorporation of 32P into polyphosphoinositides and other phospholipids in peripheral nerve of the streptozotocin diabetic rat. J Neurochem 1985; 45:1692-8. [PMID: 2997392 DOI: 10.1111/j.1471-4159.1985.tb10524.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The influence of varying doses of streptozotocin and preventive insulin treatment on phospholipid metabolism in sciatic nerve in vitro from diabetic rats was studied. Animals were given 30, 45, and 60 mg/kg injections of streptozotocin and 10 weeks later nerves were removed and incubated in the presence of [32P]-orthophosphate. The quantity of isotope incorporated into phosphatidylinositol-4,5-bisphosphate (PIP2) was progressively greater with increasing drug dosage, whereas uptake of label into other phospholipids was unchanged. Rats were made diabetic and within 72 h were implanted with long-acting, insulin-containing osmotic minipumps and the incorporation of [32P]orthophosphate into phospholipids of intact and epineurium-free nerves was examined 8 weeks later. For whole nerve, increased labeling in nerves from diabetic animals occurred only in PIP2 and phosphatidylinositol-4-phosphate (PIP) and was completely prevented by insulin treatment. Isotope incorporation into polyphosphoinositides was also markedly elevated (greater than or equal to 100%) in desheathed diabetic nerves, but not in nerves from insulin-treated animals. Other phospholipids in epineurium-free nerves displayed some rise in isotope uptake, but the increases were not prevented by insulin treatment and appeared unrelated to hyperglycemia. Morphological examination of nerves extended previous findings that prolonged insulin treatment produces axonal degeneration. These observations indicate that abnormal nerve polyphosphoinositide metabolism is at least in part a consequence of hyperglycemia. The metabolic alterations may be intimately involved in reduced nerve conduction velocity, which is characteristic of diabetic neuropathy.
Collapse
|
27
|
Sima AA, Brismar T. Reversible diabetic nerve dysfunction: structural correlates to electrophysiological abnormalities. Ann Neurol 1985; 18:21-9. [PMID: 3898998 DOI: 10.1002/ana.410180105] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Structural alterations of the nodal and paranodal areas were examined in the posterior tibial nerve in insulin-depleted and insulin-treated diabetic BB rats. The early metabolic phase of the distal symmetrical polyneuropathy was characterized by paranodal axonal swellings and nodal bulgings of the axon. These alterations correlate with intraaxonal sodium accumulation and decreased sodium equilibrium potentials which account for the early nerve conduction defect. Both the structural and electrophysiological abnormalities were completely normalized after vigorous insulin therapy. In the chronic diabetic polyneuropathy the paranodal area showed loss of paranodal axoglial junctions and paranodal myelin retraction. These changes may be partially responsible for the impaired electrical activity at the node as exemplified by irreversibly impaired sodium permeability and nerve conduction.
Collapse
|
28
|
Sharma AK, Duguid IG, Blanchard DS, Thomas PK. The effect of insulin treatment on myelinated nerve fibre maturation and integrity and on body growth in streptozotocin-diabetic rats. J Neurol Sci 1985; 67:285-97. [PMID: 3989572 DOI: 10.1016/0022-510x(85)90153-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Diabetes mellitus was produced in rats by the administration of streptozotocin and observations made over a period of 2 months. Four groups of animals were studied: onset and end controls, untreated diabetic rats and rats treated daily with a long-acting insulin preparation. Body weight increased in the end controls and insulin-treated diabetic animals to a similar degree over the observation period but was reduced in the untreated diabetic rats. Skeletal growth, assessed by measurements of tibial length, was also reduced in the untreated diabetic rats and partially corrected by insulin treatment. Myelinated fibre diameter in the tibial and sural nerves increased over the observation period in the controls, but the increase was less in the untreated animals and the growth deficit was not corrected by insulin treatment. Myelinated fibre numbers did not alter in the tibial or sural nerves between the onset and end controls. Numbers were significantly less in the tibial nerves of both the untreated and insulin-treated diabetic rats as compared with the two control groups; in the sural nerves, fibre numbers did not differ significantly between the four groups. Finally, the number of degenerating axons, assessed in teased fibre preparations, was very small in the control and untreated diabetic animals but was significantly increased in the insulin-treated group. Measurements of plasma glucose concentrations did not suggest that the axonal degeneration could be related to hypoglycaemia. The explanation for this paradoxical effect of insulin therapy is uncertain. It may be dependent upon fluctuations in blood glucose levels or other metabolic actions of insulin apart from its hypoglycaemic effect.
Collapse
|