Grip Strength In Rats Research Articles

Boosting physical performance in SD rats through brain-targeted delivery of caffeine-loaded transferrin liposomes

This study aimed to explore the impact of caffeine (CAF) encapsulated in transferrin-modified, sterically-stabilized liposomes (Tf-SSL) on the physical performance of rats, specifically forelimb grip strength, running, and swimming. The brain-targeted drug delivery system, Tf-SSL, was used for the administration of caffeine. 168 male Sprague-Dawley (SD) rats were randomly assigned to different groups, including swimming, running, running wheel, and strength groups. Each group was further subdivided into high, medium, and low dose free caffeine (HCAF, MCAF, LCAF) and Tf-SSL CAF groups, along with a control group (CON). The strength, swimming, and running groups underwent training for four weeks, three times per week. The running wheel group was placed in rearing cages for a one-week adaptation period. After the final training session, the resistance, swimming, running, and running wheel exercise capacities of the rats were tested. The rats were administered treatment via tail vein injection, while the blank CON group received 0.9 % saline solution without treatment throughout the entire process. The results demonstrated a Tf-SSL CAF group encapsulation rate of 70.58 ± 5.14 %. Increasing the concentration of supplemented caffeine led to enhanced forelimb grip strength in rats, with significant differences observed in HCAF alone group, medium-dose Tf-SSL CAF (MTf-SSL CAF), and high-dose Tf-SSL CAF (HTf-SSL CAF) groups compared to the CON group. In the running and swimming experiments, higher caffeine supplementation concentrations correlated with increased running and swimming time to exhaustion, and the MTf-SSL CAF group showed longer running and swimming time compared to the HCAF alone group. The results of rat striatal dopamine levels indicated that increased caffeine supplementation concentrations led to higher dopamine secretion, with significantly different striatal concentrations in the HCAF group, MTf-SSL CAF group, and HTf-SSL CAF group compared to the CON group. The running wheel experiment revealed that rats in the medium- and high-dose Tf-SSL CAF groups exhibited greater 6-h running distances than the HCAF group and CON group. In conclusion, caffeine supplementation improved the physical performance of rats, with the high concentration CAF group outperforming the low and medium concentration groups. Furthermore, Tf-SSL CAF demonstrated superior physical enhancement compared to caffeine supplementation alone.

High-intensity interval training improves cognitive impairment of vascular dementia rats by up-regulating expression of brain-derived neurotrophic factor in the hippocampus.

The present study aims to investigate the effect and its potential mechanism of high-intensity intermittent training (HIIT) on cognitive function in vascular dementia (VD) rats. The VD rats with the cognitive impairment were induced by bilateral common carotid artery occlusion (BCCAO), and the ones in the moderate-intensity continuous training (MICT) group and HIIT group received MICT or HIIT for 5 consecutive weeks, respectively. The swimming speed, endurance, and grip strength of rats were all measured after training. The effect and mechanisms of HIIT on ameliorating the cognitive dysfunction were further evaluated by the Morris water maze test, histomorphological analysis, and Western blot analysis. As a result, no significant difference in motor function between VD rats and sham rats was observed. After 5-week HIIT, the motor function of VD rats was significantly enhanced. The results of the Morris water maze test revealed that HIIT significantly reduced escape latency as well as distance to find the platform compared with the sedentary control group (SED group), indicating the improvement in cognitive function. In addition, the hippocampal tissue damage of VD rats measured by H&E staining was markedly ameliorated after 5-week HIIT. Moreover, brain-derived neurotrophic factor (BDNF) expression level in the cerebral cortex and hippocampus tissue detected by Western blot were significantly up-regulated in HIIT group compared to SED group and MICT group. In conclusion, HIIT can improve BCCAO-induced cognitive impairment via up-regulating BDNF expression in VD rats.

A novel view of the problem of Osteoarthritis in experimental rat model

Introduction: The article presents the results of the functional tests to improve the assessment of MIA-induced osteo­arthritis development and the effectiveness of NSAID therapy.
 Materials and methods: In the study, 26 male SD rats were used. MIA-induced osteoarthritis was simulated in the right knee joint. After an intra-articular injection of MIA, the animals were treated with ibuprofen and meloxicam. Pain assessment was studied in the following functional tests: incapacitance (hind limb weight bearing) test, von Frey test (mechanical allodynia), grip strength test, and knee diameter measurement. At the end of the study, a histological analysis of the knee joint was performed.
 Results and discussion: An intra-articular MIA injection reduced 1.5 times the paw withdrawal threshold. In the rats that suffered MIA-induced osteoarthritis, the difference between the diameters of the intact and injected joints was 1.05 mm, compared to 0.03 mm difference in the control group. Hind limb weight bearing asymmetry was 89.5% when simulating MIA-induced osteoarthritis. The muscular hind limb grip strength in rats with MIA-induced osteoarthritis was significantly reduced on 3rd and 7th days after simulating osteoarthritis. Ibuprofen and meloxicam showed signif­icant efficacy in all the above tests, although ibuprofen effectiveness was more pronounced than that of meloxicam.
 Conclusion: The following functional tests were identified as the most significant and sufficient to assess the devel­opment of MIA-induced osteoarthritis and analgesic efficacy of NSAIDs: incapacitance test, allodynia test (von Frey filaments), measurement of hind limb grip strength and measurement of the diameter of the inflamed knee joint. The histological analysis made it possible to confirm the correspondence of the physiological response and pathological changes in the knee joint.

The Effect Of Resistance Training During Chemotherapy On Grip Strength In Rats.

The Effect Of Resistance Training During Chemotherapy On Grip Strength In Rats.

Grip strength evaluation of Wistar rats submitted to a model of median nerve compression treated with neural mobilization

Among the technical features of median nerve compression, may include: pain, paresthesias and grip strength decreased. There are several treatment options, but no therapy is universally accepted, some still occurring for unwanted side effects. The neural mobilization is one of the possibilities held with stretching of the nerve distal to mobilization. Thus the aim of this study was to assess the grip strength in rats submitted to the model of median nerve compression treated with neural mobilization. We used 10 Wistar rats divided into 2 groups: CG (n=5) – subject to nerve compression and untreated; NMG (n=5) – subject to nerve compression and treated with neural mobilization for 3 minutes in 3 rd , 5 th and 7 th postoperatively (PO). To perform the compression of the median nerve was performed knot with wired Catgut 4.0 Chrome in 4 points, with a distance of approximately 1 mm in the median nerve in the proximal region to the right elbow. Muscle strength was assessed using grip strength meter, with the animals can cling to the instrument and pulled by the tail, the evaluations occurred before the injury and on the 3 rd , 5 th , 7 th and 9 th PO. For both groups a significant decrease in values after pre-injury, and the comparison between groups did not differ. It is concluded that the use of neural mobilization in animals subjected to a compression of the median nerve had no effect on the grip strength in rats.

Assessment of chemically-induced changes in the neuromuscular function of rats using a new recording grip meter

The effects of several psychoactive drugs on the grip strength of rats were evaluated by a new recording grip meter technique that provides graded or continuous data. The same subjects were also tested by an inclined screen procedure, which yields quantal or all-or-none data. The lowest doses (lowest effective dose; LED) required to produce a significant decrease in grip meter scores by chlorpromazine (CPZ), chlordiazepoxide (CDZ), and phenobarbital (PHEN) were 5, 9, and 20 mg/kg respectively. d -Amphetamine (0.5– 8 mg/kg) resulted in a significant, dose-related increase in grip meter scores. The LEDs for CPZ and PHEN using the inclined screen test were 10 and 40 mg/kg, respectively. These values are 2 times the corresponding figures obtained in the grip meter test. The LED for chlordiazepoxide was 9 mg/kg in the inclined screen, which is the same as that in the grip meter test, while d -amphetamine had no effect on neuromuscular function measured by the inclined screen. The results of these experiments indicate that the grip method is a useful technique capable of measuring both increases and decreases in the grip strength of rats. Relative to the inclined screen procedure, which measures a combination of factors, the grip meter technique appears to be a sensitive procedure capable of measuring forelimb grip strength selectively.

A simple recording grip strength device

A simple-to-construct, inexpensive recording strain gauge device which may be used to obtain graded measurements of forelimb grip strength in rats and mice is described.