title: Sweating response to passive stretch of the calf muscle during activation of forearm muscle metaboreceptors in heated humans.
abstract: Activation of muscle metaboreceptors and mechanoreceptors has been shown to independently influence the sweating response, while their integrative control effects remain unclear. We examined the sweating response when the two muscle receptors are concurrently activated in different limbs, as well as the blood pressure response. In total, 27 young males performed passive calf muscle stretches (muscle mechanoreceptor activation) for 30 s in a semisupine position with and without postisometric handgrip exercise muscle ischemia (PEMI, muscle metaboreceptor activation) at exercise intensities of 35 and 50% of maximum voluntary contraction (MVC) under hot conditions (ambient temperature, 35°C, relative humidity, 50%). Passive calf muscle stretching alone increased the mean sweating rate significantly on the forehead, chest, and thigh (SRmean) and mean arterial blood pressure (MAP), but not the heart rate (HR), from prestretching levels by 0.04 ± 0.01 mg·cm(2)·min(-1), 4.0 ± 1.3 mmHg (P < 0.05), and -1.0 ± 0.5 beats/min (P > 0.05), respectively. The SRmean and MAP during PEMI were significantly higher than those at rest. The passive calf muscle stretch during PEMI increased MAP significantly by 3.4 ± 1.0 and 2.0 ± 0.7 mmHg for 35 and 50% of MVC, respectively (P < 0.05), but not that of SRmean or HR at either exercise intensity. These results suggest that sweating and blood pressure responses to concurrent activation of the two muscle receptors in different limbs differ and that the influence of calf muscle mechanoreceptor activation alone on the sweating response disappears during forearm muscle metaboreceptor activation.
authors.affiliation: Laboratory for Applied Human Physiology, Graduate School of Human Development and Environment, Kobe University, Kobe, Japan;
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Amano
authors.affiliation: Human Integrative Physiology Laboratory, School of Business Administration, Meiji University, Tokyo, Japan;
authors.forename: Masashi
authors.initials: M
authors.lastname: Ichinose
authors.affiliation: Institute of Health and Sports Science, University of Tsukuba, Tsukuba, Japan;
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishiyasu
authors.affiliation: Laboratory for Human Performance Research, Osaka International University, Osaka, Japan; and.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: Applied Physiology Laboratory, Kobe Design University, Kobe, Japan.
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Koga
authors.affiliation: Laboratory for Applied Human Physiology, Graduate School of Human Development and Environment, Kobe University, Kobe, Japan;
authors.forename: Mikio
authors.initials: M
authors.lastname: Miwa
authors.affiliation: Laboratory for Applied Human Physiology, Graduate School of Human Development and Environment, Kobe University, Kobe, Japan; kondo@kobe-u.ac.jp.
authors.forename: Narihiko
authors.initials: N
authors.lastname: Kondo
mesh_terms: D001132:Arm / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology*; D001833:Body Temperature Regulation / Q000502:physiology*; D005542:Forearm; D018737:Hand Strength / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D007866:Leg / Q000502:physiology; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D052580:Muscle Stretching Exercises; D018482:Muscle, Skeletal / Q000502:physiology*; D013546:Sweating / Q000502:physiology*; D055815:Young Adult
keywords: group III and IV muscle afferents; nonthermal factors; sweat gland; sympathetic nervous system; thermoregulation