OBJECTIVE: To study the morphological changes of the rat claw inner skeletal muscle after ulnar nerve injury at different sections and different recovery times. METHODS: Forty-two adult male Sprague-Dawley rats were selected and placed randomly in seven groups. After establishing model of injury and repair of claw inner skeletal muscle by cutting off the ulnar nerve, the muscle wet weight, cross section area of myocytes, and collagen fibers were measured. RESULTS: Claw inner skeletal muscle atrophy was significantly less in experiment groups compared with the control groups after ulnar nerve injuries. The functional recovery was better in the early repair groups than the late repair group. Collagen fibers increased slowly in earlier stage, but more significantly in late stage. The muscle atrophy was similar in wrist and elbow after ulnar nerve injury during the same recovery period. CONCLUSION The function can recover completely or partly in early repair groups, but not quite effective in late stage. The increase of collagen fiber is one of the reasons to undermine the recovery effect of damaged ulnar nerve. There is no obvious difference of effect on the morphological changes of the rat claw inner skeletal muscle no matter the ulnar nerve is injured at wrist or elbow.
Animals ; Male ; Muscle, Skeletal/pathology* ; Muscular Atrophy/prevention & control* ; Nerve Regeneration/physiology* ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Plastic Surgery Procedures ; Ulnar Nerve/surgery*

PURPOSE: The purpose of this study was to determine the effect of Dehydroepiandrosterone (DHEA) administration alone or exercise combined with DHEA before steroid treatment on rat hindlimb muscles. METHODS: Male Sprague-Dawley rats were assigned to one of three groups: a steroid group (S, n=10) that had no treatment for 7 days before steroid treatment; a DHEA-steroid group (DS, n=8) that had 0.34 mmol/kg/day DHEA injection once a day for 7 days before steroid treatment and an exercise?steroid group (EDS, n=9) that ran on the treadmill combined with 0.34 mmol/kg/day DHEA injection for 7 days before steroid treatment. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Body weight, food intake, muscle weight, myofibillar protein content and cross-sectional area of the dissected muscles were determined. RESULTS: The DS group showed significant increases (p<.05) as compared to the steroid group in body weight, and muscle weight of gastrocnemius muscles. The EDS group showed significant increases (p<.05) as compared to the S group in body weight, muscle weight, myofibrillar protein content, and Type II fiber cross-sectional area of soleus, plantaris and gastrocnemius muscles. CONCLUSION: Exercise combined with DHEA administration before steroid treatment prevents steroid induced muscle atrophy, with exercise combined with DHEA administration being more effective than DHEA administration alone in preventing muscle atrophy.
Animals ; Body Weight ; Dehydroepiandrosterone/*administration & dosage ; Hindlimb ; Male ; Muscle Contraction/drug effects ; Muscle, Skeletal/*drug effects/pathology ; Muscular Atrophy/chemically induced/*prevention & control ; *Physical Conditioning, Animal ; Rats ; Rats, Sprague-Dawley ; Steroids/*toxicity

AIMTo study the effect of radix-astragali compound(RC) on muscle atrophy in tail-suspended rats. Muscle weight, fiber type distribution, cross-sectional area (CSA), and activity of myosin adenosine triphosphatase (ATPase) in rat soleus muscle were investigated.

METHODSThe tail-suspended rats were subjected to a 14 days simulated weightlessness, during which period, RC or saltwater was given via intragastric instillation during tail suspension. The changes of soleus muscle weight were scaled by muscle-to-body weight ratio. The activities of myosin ATPase of muscle fibers were detected by method of Ca(2+) -ATPase.

RESULTSAfter a 14 days tail suspension it was found: in rats treated with RC, soleus muscle-to-body weight ratio rose by 33.33% (P < 0.01), both CSA of type I and II fiber drastically enhanced by(143.03%, P < 0.01; 83.25%, P < 0.01), the percentage of type I fiber significantly declined compared to the untreated rats.

CONCLUSIONRC is able to effectively prevent muscle atrophy caused by tail suspension and restrain the increase in the myosin ATPase activities caused by simulated weightlessness.

Animals ; Drugs, Chinese Herbal ; pharmacology ; Hindlimb Suspension ; Male ; Muscle Fibers, Skeletal ; enzymology ; Muscle, Skeletal ; drug effects ; enzymology ; Muscular Atrophy ; prevention & control ; Myosins ; metabolism ; Rats ; Rats, Sprague-Dawley ; Weightlessness Simulation ; methods

OBJECTIVETo study the effects of Ligusticum and its two components (Sodium Ferulate and Ligustrazine as main efficacy components in Ligusticum for invigorating blood circulation) on muscle atrophy in a hind limb unloaded rat model.

METHODSThe tail-suspended rats were subjected to a 14-days disuse, immunohistochemistry and hemorheology were used to study the effects of medicines on soleus muscle.

RESULTSCompared with HLU+ W: (1) The CSA of soleus type I fibers in HLU + SfH and HLU+ TmpH increased by 37.3% and 39.4% respectively (P < 0.05). (2) Expression level of MHC II were inhibited in all treatment groups (P < 0.01). (3) Expression of MHC II in nuclear bag 2 fiber were altered from positive to negative. (4) The blood viscosity in low shear rates decreased obviously (P < 0.01), even near to control.

CONCLUSIONLigusticum and its two main efficacy components (Sodium Ferulate and Ligustrazine) can prevent soleus atrophy induced by disuse, and Sodium Ferulate and Ligustrazine in high dose showed most efficacy.

Animals ; Coumaric Acids ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Extremities ; Female ; Hemorheology ; Hindlimb Suspension ; Ligusticum ; chemistry ; Muscle Fibers, Skeletal ; drug effects ; Muscular Atrophy ; blood ; etiology ; prevention & control ; Myosin Heavy Chains ; metabolism ; Pyrazines ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

To study the effects of ciliary neurotrophic factor (CNTF) on denervated skeletal muscle atrophy and to find a new approach to ameliorate atrophy of denervated muscle, a model was established by cutting the right sciatic nerve in 36 Wistar mice, with the left side serving as control. Then they were divided into two groups randomly. CNTF (1 U/ml) 0.1 ml was injected into the right tibial muscle every day in experimental group, and saline was used into another group for comparison. The muscle wet weight, muscle total protein, Ca2+, physiological response and morphology were analyzed on the 7th, 14th and 28th day after operation. Our results showed that compared to control group, there was a significant increase in muscle wet weight, total protein, Ca2+, muscle fiber cross-section area in CNTF group (P < 0.05). CNTF could ameliorate the decrease of tetanic tension (PO), post-tetanic twitch potentiation (PTP), and the prolonged muscle relaxation time (RT) caused by denervation (P < 0.05). The motor end-plate areas 7 days and 14 days after denervation was similar (P > 0.05), but significantly larger 28 days after the denervation (P < 0.05). Our results suggest that CNTF exerts myotrophic effects by attenuating the morphological and functional changes associated with denervation of rat muscles and has protective effects on denervated muscle and motor end plate.
Animals ; Ciliary Neurotrophic Factor ; pharmacology ; Male ; Motor Endplate ; pathology ; physiopathology ; Muscle Denervation ; adverse effects ; Muscle, Skeletal ; innervation ; pathology ; physiopathology ; Muscular Atrophy ; etiology ; prevention & control ; Random Allocation ; Rats ; Rats, Wistar ; Sciatic Nerve ; surgery

OBJECTIVETo explore measures to prevent motor endplate degeneration and muscular atrophy after motor nerve injury.

METHODSThirty Sprague-Dawley rats were randomized into 3 equal groups. In two of the groups, the right common peroneal nerves of the rats were transected and immediately sutured with implantation of collagen gel carrier of acidic fibroblast growth factor (aFGF) or the empty carrier into the denervated tibialis anterior muscles. In the control group, the transected nerves were sutured without implantation. Six weeks after the operation, morphological and electrophysiological examinations were performed.

RESULTSIn the control rats and those with empty collagen gel carrier implantation, obvious motor endplate degeneration and muscular atrophy occurred, which were not obvious in rats receiving aFGF carrier implantation. The decrement of repetitive nerve stimulation was significantly greater in the former two groups than in the latter.

CONCLUSIONImplantation of collagen gel carrier of aFGF may prevent motor endplate degeneration and facilitate functional recovery of the neuromuscular junction after motor nerve injury.

Animals ; Electrophysiology ; Female ; Fibroblast Growth Factor 1 ; pharmacology ; therapeutic use ; Male ; Motor Endplate ; drug effects ; injuries ; physiopathology ; Muscle Denervation ; methods ; Muscular Atrophy ; pathology ; physiopathology ; prevention & control ; Nerve Degeneration ; physiopathology ; prevention & control ; Nerve Regeneration ; drug effects ; Peroneal Nerve ; drug effects ; injuries ; physiopathology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of Astragali Radix on the denervated tibial muscle atrophy in rats, and discuss its mechanism.

METHODTotally 60 SPF-grade Sprague-Dawley rats were selected in the common peroneal nerve crush model, and then randomly divided into 6 groups: Astragali Radix high-dose, medium-dose, low-dose groups, the Mecobalamin group, the model group, and the sham operation group. They were administered with drugs after the operation. At 18 d, the pathological section staining and morphological analysis were performed. The wet-weight ratio and section area of tibial muscles were also measured. The real-time fluorescence quantification was adopted to detect the differential expression between Angptl4 and PI3K genes.

RESULT(1) Wet-weight ratio: The wet-weight ratio in Astragali Radix high-dose, medium-dose groups was much higher than that in the model group (P < 0.05 or P < 0.01). (2) Section area: The sham operation group was higher, with regular morphology; Whereas the model group showed significant decrease, with chaotic structure and obvious connective tissue proliferation; Astragali Radix groups and the mecobalamin group showed relatively small section areas, with chaotic structure and unobvious connective tissue proliferation. Compared with the model group, Astragali Radix groups showed significant increase (P < 0.01). (3) Motor end plate: The sham operation group was in uniform brownish black color and oval or round shape; Astragali Radix medium-dose and high-dose group and the mecobalamin group showed rough line edges; Astragali Radix medium-dose and low-dose groups and the model group showed decline in the number, with irregular morphology, rough line edges and a light color. (4) Angptl4 and PI3K: Compared with the model group, the Astragali Radix high-dose group showed significant increase (P < 0.05).

CONCLUSIONAstragali Radix has a significant effect in preventing and treating denervated tibial muscle atrophy. It may delay the muscle atrophy by increasing Angptl4 and PI3K gene expressions.

Angiopoietin-like 4 Protein ; Angiopoietins ; genetics ; Animals ; Astragalus Plant ; Astragalus membranaceus ; chemistry ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Gene Expression Regulation ; drug effects ; Male ; Muscular Atrophy ; drug therapy ; genetics ; pathology ; prevention & control ; Phosphatidylinositol 3-Kinases ; genetics ; Rats ; Rats, Sprague-Dawley ; Tibia