The effect of local passive heating on skeletal muscle histamine concentration: Implications for exercise-induced histamine release

Aerobic exercise induces mast cell degranulation and increases histamine formation by histidine decarboxylase, resulting in an ~150% increase in intramuscular histamine. The purpose of this study was to determine if the increase in skeletal muscle temperature associated with exercise is sufficient to explain this histamine response. Specifically, we hypothesized that local passive heating that mimics the magnitude and time-course of changes in skeletal muscle temperature observed during exercise would result in increased intramuscular histamine concentrations comparable to exercising values. Seven subjects participated in the main study in which pulsed short-wave diathermy was used to passively raise the temperature of the vastus lateralis over 60 min. Heating increased intramuscular temperature from 32.6 (95% CI 32.0 to 33.2) to 38.9 (38.7 to 39.2) oC (P < 0.05) and increased intramuscular histamine concentration from 2.14 (1.92 to 2.36) to 2.97 (2.57 to 3.36) ng/ml (P < 0.05), an increase of 41%. In a follow-up in vitro experiment utilizing human-derived cultured mast cells, heating to comparable temperatures did not activate mast cell degranulation. Therefore, it appears that exercise-associated changes in skeletal muscle temperature are sufficient to generate elevations in intramuscular histamine concentration. However, this thermal effect is most likely due to changes in de novo histamine formation via histidine decarboxylase and not due to degranulation of mast cells. In conclusion, physiologically relevant increases in skeletal muscle temperature explain part, but not all, of the histamine response to aerobic exercise. This thermal effect may be important in generating the positive adaptations to exercise training.

A comparison of moist heat, dry heat, chemical dry heat and icy hot for deep tissue heating and changes in tissue blood flow.

Background: Intermittent bouts of heavy activity at greater than normal exercise intensity can cause delayed onset muscle soreness (DOMS). Several products are commercially available, all alleging to reduce DOMS. In the present investigation, 40 subjects (average age 27.0+/-4.4 years, average BMI 26.8) were assessed to determine the effect of 4 of these products on skin and muscle temperature and blood flow during 2 hours of application. These included ThermaCare Dry Heat Wraps, ThermaCare Moist Heat Wraps, Icy Hot Patches, and hydrocollator heat packs. Methods; Blood flow was measured (by laser doppler flow meter) over and in the quadriceps muscle and tissue temperature was measured (by thermistors and thermocouples) in these same areas. Results: The results of the study indicated that only ThermaCare Dry and Moist Heat Wraps both heated the muscle and increased muscle blood flow. The menthol and methyl salicylate compounds in Icy Hot cooled muscle. Skin blood flow increased 300% after the moist heat was applied after 45 minutes, low level continuous dry heat almost 256% but it took 105 minutes to reach this flow, hydrocollator heat wraps increased by 201% but only for only first 45 minutes and then back to baseline, a slight reduction in skin blood flow was seen with Icy Hot gel applied to the skin. Moist heat caused muscle temperature to increase by an average of 3.1 Deg C. Dry heat caused muscle temperature to increase by 2.2 Deg C, while hydrocollator packs increased temperature by 0.4 Deg C. Icy hot had no effect on muscle temperature. Conclusion: Continuous low level heat products had better penetration into muscle and increased blood flow the best compared to hydrocollator heat packs and Icy Hot patches.

Diagnosis of Temporomandibular Disorders Using Thermovision Imaging

Temporomandibular joint dysfunction (TMD) is a chronic disease of various etiologies. Correct TMD diagnosis enables to apply effective treatment and significantly improves the quality of patients’ lives. One of the diagnostic methods subjected to evaluation in recent years is thermography, which enables safe, noninvasive, and quick imaging of the temperature distribution of temporomandibular joint-associated tissues. This paper, based on Medline, Dentistry & Oral Sciences Source, Academic Search Ultimate, Medline Complete databases, presents basic information related to thermovision imaging and outlines the direction of research conducted in recent years which fight with difficulties in the interpretation of thermograms that require specialized, dedicated analysis and processing of the obtained images. The problem concerns also no standardized protocol for measuring masticatory muscle temperature.

Is GLUT4 translocation the answer to exercise stimulated muscle glucose uptake?

Exercise increases muscle glucose uptake up to 100 fold compared to rest. The magnitude of increase depends on exercise intensity and duration. While KO of GLUT4 convincingly has shown that GLUT4 is necessary for exercise to increase muscle glucose uptake, studies only show an approximate 2-fold increase in GLUT4 translocation to the muscle cell membrane when transitioning from rest to exercise. Therefore, there is a big discrepancy between the increase in glucose uptake and GLUT4 translocation. It is suggested that either the methods for measurements of GLUT4 translocation in muscle grossly underestimate the real translocation of GLUT4 or alternatively that GLUT4 intrinsic activity increases in muscle during exercise, perhaps due to increased muscle temperature and/or mechanical effects during contraction/relaxation cycles.

Effects of Ibuprofen Intake in Muscle Damage, Body Temperature and Muscle Power in Paralympic Powerlifting Athletes

The aim of this study is to evaluate the effect of ingesting ibuprofen on post-workout recovery of muscle damage, body temperature and muscle power indicators in Paralympic powerlifting athletes. The study was carried out with eight Paralympic powerlifting athletes (aged 27.0 ± 5.3 years and 79.9 ± 25.5 kg of body mass) competing at the national level, with a minimum training experience of 12 months, who all submitted to two experimental conditions: Ibuprofen (2 × 00 mg) and control. The maximal isometric force of the upper limbs and rate of force development, thermography, and serum biochemical analyzes of creatine kinase, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were measured before, after, 24 h after and 48 h after the intervention. Maximal isometric force only decreased in the placebo condition, which increased back to baseline levels, while no substantial decline in baseline force was seen in the ibuprofen condition, although no effect for exercise condition was detected. After the exercise, the rate of force development decreased significantly for both conditions and did not exceed baseline levels again after 48 h. Muscle temperature decreased significantly at 48-h post-exercise in the placebo condition, when compared with the previous day of measurement; and deltoid muscle temperature at 48-h post-exercise was higher with the ibuprofen condition. Although the results indicate some positive effects of ibuprofen use, they do not enable a clear statement regarding its positive effects on muscle function and muscle damage. Ibuprofen seems to have caused a delay in the anti-inflammatory response following exercise.