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Sánchez CS, García OL, Ruiz MDLÁC, Pacheco P, Martínez-Gómez M, Corona-Quintanilla DL, Rodríguez-Antolín J, Castelán F, Nicolás-Toledo L. High-sucrose diet-fed male rats show affectations in pubococcygeus reflex activation and myofiber content. Tissue Cell 2023; 82:102047. [PMID: 36841128 DOI: 10.1016/j.tice.2023.102047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/18/2023] [Accepted: 02/19/2023] [Indexed: 02/23/2023]
Abstract
In males, the function of the pubococcygeus muscle (Pcm) shows a high androgen dependency. High sucrose intake increases testosterone levels in pubertal male rats. We aimed to analyze the Pcm reflex activity and fiber type in response to a 30 % sucrose diet. Wistar male rats were assigned into two groups: control and sugar. The Pcm electromyographic activity was recorded during the mechanical stimulation of the scrotal skin and penis. We also determined the relative levels of Glut4 expression, glycogen content, myofiber cross-sectional area (CSA), and the content of glycolytic and oxidative with NADH-TR or fast, intermediate, and slow fibers with alkaline (pH 9.4) ATPase histochemistry. The sugar group showed a short Pcm reflex activity, a higher Glut4 expression, and glycogen content; the CSA fibers showed a significant difference in the percentage of fibers with the different transversal areas. The number of nuclei was positively correlated with the CSA of the Pcm fibers. There was also a decrease in oxidative fibers but an increase in glycolytic fibers, while the content of fast muscle fibers increased to the detriment of intermediate and slow fibers. Thus, a high-sugar diet reduced Pcm reflex activity, fiber type, and dysregulation of skeletal muscle energy metabolism.
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Affiliation(s)
| | - Omar Lara García
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México.
| | | | - Pablo Pacheco
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México; Instituto de Neuroetología, Universidad Veracruzana, Xalapa, Veracruz, México.
| | - Margarita Martínez-Gómez
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México.
| | | | - Jorge Rodríguez-Antolín
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México.
| | - Francisco Castelán
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México.
| | - Leticia Nicolás-Toledo
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala, México.
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Seppan P, Muhammed I, Mohammad ZIK, Sathyanathan SB. Pathobiology of ischiocavernosus and bulbospongiosus muscles in long-term diabetic male rats and its implication on erectile dysfunction. Aging Male 2020; 23:979-990. [PMID: 31368398 DOI: 10.1080/13685538.2019.1647160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE To analyze pathobiology of ischiocavernosus (IC) and bulbospongiosus (BS) muscles in long-term diabetic male rats and its implication on erectile dysfunction (ED). METHODS Male rats were grouped into control and diabetic rats (received single injection of 60 mg/kg bw. of streptozotocin [STZ]). At 120th day, the animals were subjected to various analyses like serum hormone, penile reflex, electromyography of IC and BS muscles, after euthanasia IC and BS muscles were processed for morphological, histology, histometric analysis, immunostaining and immunoblotting synaptophysin, nNOS and NADPH diaphorase histochemistry. RESULTS Significant reduction in serum hormone level, penile reflex, reduced action potential or activity in both these muscles and wide range of histological alterations were observed in STZ rats. Muscles showed significant reduction in the diameter, volume and numerical density of the fiber in both muscles of STZ rats. Synaptophysin, nNOS and NADPH diaphorase were significantly reduced in diabetic animal IC and BS. CONCLUSION Severe neuromuscular circuitry alteration in IC and BS. Study concludes that degenerative changes in IC and BS may play a major role in ED in diabetic condition. Indicating diabetic-induced postsynaptic neuronal degeneration along with impaired motor action of the muscle and severe muscle degeneration affecting ED.
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Affiliation(s)
- Prakash Seppan
- Department of Anatomy, Dr. Arcot Lakshmanasamy Mudaliar Postgraduate Institute of Basic Medical Sciences, University of Madras, Chennai, Tamil Nadu, India
| | - Ibrahim Muhammed
- Department of Anatomy, Dr. Arcot Lakshmanasamy Mudaliar Postgraduate Institute of Basic Medical Sciences, University of Madras, Chennai, Tamil Nadu, India
| | - Zafar Iqbal Khan Mohammad
- Department of Anatomy, Dr. Arcot Lakshmanasamy Mudaliar Postgraduate Institute of Basic Medical Sciences, University of Madras, Chennai, Tamil Nadu, India
| | - Sathya Bharathy Sathyanathan
- Department of Electrical and Electronics Engineering, Loyola-ICAM College of Engineering and Technology, Chennai, Tamil Nadu, India
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Diabetes Mellitus-Related Dysfunction of the Motor System. Int J Mol Sci 2020; 21:ijms21207485. [PMID: 33050583 PMCID: PMC7589125 DOI: 10.3390/ijms21207485] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 12/20/2022] Open
Abstract
Although motor deficits in humans with diabetic neuropathy have been extensively researched, its effect on the motor system is thought to be lesser than that on the sensory system. Therefore, motor deficits are considered to be only due to sensory and muscle impairment. However, recent clinical and experimental studies have revealed that the brain and spinal cord, which are involved in the motor control of voluntary movement, are also affected by diabetes. This review focuses on the most important systems for voluntary motor control, mainly the cortico-muscular pathways, such as corticospinal tract and spinal motor neuron abnormalities. Specifically, axonal damage characterized by the proximodistal phenotype occurs in the corticospinal tract and motor neurons with long axons, and the transmission of motor commands from the brain to the muscles is impaired. These findings provide a new perspective to explain motor deficits in humans with diabetes. Finally, pharmacological and non-pharmacological treatment strategies for these disorders are presented.
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MacDonell CW, Chopek JW, Gardiner KR, Gardiner PF. α-Motoneurons maintain biophysical heterogeneity in obesity and diabetes in Zucker rats. J Neurophysiol 2017; 118:2318-2327. [PMID: 28747469 DOI: 10.1152/jn.00423.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 07/24/2017] [Accepted: 07/24/2017] [Indexed: 12/14/2022] Open
Abstract
Small-diameter sensory dysfunction resulting from diabetes has received much attention in the literature, whereas the impact of diabetes on α-motoneurons (MN) has not. In addition, the chance of developing insulin resistance and diabetes is increased in obesity. No study has examined the impact of obesity or diabetes on the biophysical properties of MN. Lean Zucker rats and Zucker diabetic fatty (ZDF) rats were separated into lean, obese (ZDF fed standard chow), and diabetic (ZDF fed high-fat diet that led to diabetes) groups. Glass micropipettes recorded hindlimb MN properties from identified flexor and extensor MN. MN were separated within their groups on the basis of input conductance, which created high- and low-input conductance subpopulations for each. A significant shorter (20%) afterhyperpolarization half-decay (AHP1/2) was found in low-conductance MN for the diabetic group only, whereas AHP½ tended to be shorter in the obese group (19%). Significant positive correlations were found among rheobase and input conductance for both lean and obese animals. No differences were found between the groups for afterhyperpolarization amplitude (AHPamp), input conductance, rheobase, or any of the rhythmic firing properties (frequency-current slope and spike-frequency adaptation index). MN properties continue to be heterogeneous in obese and diabetic animals. Obesity does not seem to influence lumbar MN. Despite the resistance of MN to the impact of diabetes, the reduced AHP1/2 decay and the tendency for a reduction in AHPamp may be the first sign of change to MN function.NEW & NOTEWORTHY Knowledge about the impact of obesity and diabetes on the biophysical properties of motoneurons is lacking. We found that diabetes reduces the duration of the afterhyperpolarization and that motoneuron function is unchanged by obesity. A reduced afterhyperpolarization may impact discharge characteristics and may be the first sign of change to motoneuron function.
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Affiliation(s)
- Christopher W MacDonell
- Spinal Cord Research Centre, Department of Physiology & Pathophysiology, Rady Faculty of Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jeremy W Chopek
- Spinal Cord Research Centre, Department of Physiology & Pathophysiology, Rady Faculty of Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Kalan R Gardiner
- Spinal Cord Research Centre, Department of Physiology & Pathophysiology, Rady Faculty of Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Phillip F Gardiner
- Spinal Cord Research Centre, Department of Physiology & Pathophysiology, Rady Faculty of Health, University of Manitoba, Winnipeg, Manitoba, Canada
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Muramatsu K, Niwa M, Tamaki T, Ikutomo M, Masu Y, Hasegawa T, Shimo S, Sasaki SI. Effect of streptozotocin-induced diabetes on motoneurons and muscle spindles in rats. Neurosci Res 2016; 115:21-28. [PMID: 27826051 DOI: 10.1016/j.neures.2016.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 10/17/2016] [Accepted: 10/27/2016] [Indexed: 12/30/2022]
Abstract
This study examined the alterations in the number and size of motoneurons innervating the medial gastrocnemius (MG) and biceps femoris (BF) motor nuclei in diabetic rats (12 or 22 weeks after injection of streptozotocin) and age-matched controls using retrograde labeling technique. Additionally, morphological alterations of muscle spindles in BF and MG muscles were tested. Significantly fewer labeled MG motoneurons were found in 12- and 22-week diabetic rats as compared with age-matched control animals. In contrast, the number of BF motoneurons was preserved in each group. Compared to control animals, the ratio of larger motoneurons of MG and BF muscle were decreased at 12 weeks, and smaller MG motoneurons were drastically decreased at 22 weeks. Moreover, MG muscle spindle showed reduction of its number and increase of intrafusal muscle fibers; however, BF muscle spindles showed little or no difference from control animals. We conclude that there is an early loss of alpha motoneurons for both MG and BF muscles followed by a later loss of gamma motoneurons in MG muscle in diabetic animals. Moreover, loss of gamma motoneuron might induce atrophy of MG muscle spindles.
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Affiliation(s)
- Ken Muramatsu
- Department of Physical Therapy, Health Science University, Yamanashi, Japan.
| | - Masatoshi Niwa
- Department of Occupational Therapy, Kyorin University, Tokyo, Japan
| | - Toru Tamaki
- Department of Physical Therapy, Health Science University, Yamanashi, Japan
| | - Masako Ikutomo
- Department of Physical Therapy, Health Science University, Yamanashi, Japan
| | - Yujiro Masu
- Department of Physical Therapy, Health Science University, Yamanashi, Japan
| | - Tatsuya Hasegawa
- Division of Human Environmental Science, Mount Fuji Research Institute, Yamanashi, Japan
| | - Satoshi Shimo
- Department of Occupational Therapy, Health Science University, Yamanashi, Japan
| | - Sei-Ichi Sasaki
- Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan
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Muramatsu K, Niwa M, Nagai M, Kamimura T, Sasaki SI, Ishiguro T. The size of motoneurons of the gastrocnemius muscle in rats with diabetes. Neurosci Lett 2012; 531:109-13. [PMID: 23127853 DOI: 10.1016/j.neulet.2012.10.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 10/07/2012] [Accepted: 10/19/2012] [Indexed: 11/15/2022]
Abstract
Alterations in the number and size of motoneurons were studied in the medial gastrocnemius (MG) motor nucleus of diabetic rats (12 or 22 weeks after injection of storeptozotocin) and age-matched controls. Each group contained 6 animals. MG motoneurons were retrogradely labeled by dextran-fluorescein and the number and size of cell bodies were examined. Significantly fewer labeled MG motoneurons were found in the 22-week diabetic rats as compared with age-matched control animals. The mean soma diameter of MG motoneurons was significantly smaller in the 12- and 22-week diabetic animals. Furthermore the soma size for 22-week diabetic animals was smaller than for 12-week diabetic animals. The distribution of average soma diameters in the MG nucleus of control animals was bimodal; cells with larger average diameter were presumed to be alpha-motoneurons and those with smaller diameters were presumed to be gamma. Compared to control animals, the number of smaller MG motoneurons was reduced in 12 week diabetic animals. By 22 weeks, diabetic animals had no small MG motoneurons and the size distribution became unimodal. We conclude that there is a significant decrease in the absolute number and size of MG motoneurons in diabetic rats, with the possibility that the decrease occurred predominantly among the smaller gamma-motoneurons.
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Affiliation(s)
- Ken Muramatsu
- Department of Physical Therapy, Health Science University, Yamanashi, Japan.
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