Attenuation of natural killer cell activity during 2-h exercise in individuals with spinal cord injuries

Abstract

Design: Non-randomized study. Objective: To determine natural killer cell cytotoxic activity (NKCA) to 2-h arm ergometer exercise in persons with spinal cord injuries (SCI) and the underlying mechanism of such response. Setting: University of Occupational and Environmental Health, Japan. Methods: We examined NKCA response to 2-h arm crank ergometer exercise at 60% of maximum oxygen consumption (VO 2max ) in SCI and able-bodied persons. NKCA and plasma concentrations of prostaglandin E 2 (PGE 2 ), adrenaline and cortisol were measured before, during and immediately after the exercise. The study included seven subjects with SCI between Th11 and L4 and six able-bodied persons.Results: NKCA in able-bodied subjects increased (Po0.05) at 60 min of exercise and immediately after the exercise, and remained elevated up to 2 h after exercise. However, NKCA in SCI decreased (Po0.05) immediately after exercise but recovered at 2 h after exercise. Plasma adrenaline in both groups increased significantly (Po0.05) immediately after exercise and returned to baseline level 2 h after the exercise. Plasma cortisol in both groups remained constant throughout the study. In SCI, PGE 2 significantly increased immediately after 2 h exercise and returned to the baseline level 2 h after exercise; however, it remained unchanged during the test in able-bodied subjects. Conclusion: Our results suggested that increase of PGE 2 in SCI partially contributes to NKCA.

Impaired immune response to voluntary arm-crank ergometer exercise in patients with cervical spinal cord injury

“…10 NKCA increased significantly in AB immediately after exercise, but decreased significantly in SCI immediately after exercise. 10 Cortisol levels remained constant throughout the experiment in all subjects. In this study, with substantially shorter exercise duration, NKCA in CSCI did not decrease immediately after exercise.…”

“…for 3 min before the supernatant was removed, and cells were then resuspended in 250 ml 1% Other blood tests Total blood cell counts, hematocrit, the percentage of neutrophils, total lymphocytes, and monocytes, plasma catecholamines, and cortisol levels were measured using the methods described earlier. 10 Statistical analysis Data were expressed as mean±standard error of the mean (s.e.m.) and analyzed using a 2 Â 4 repeated measures analysis of variance (ANOVA).…”

“…5 Very few studies have examined the immunological changes after exercise in SCI. [6][7][8][9][10] We reported previously that competitive wheelchair athletes with paraplegia show decreased peripheral NK cell numbers and NKCA immediately after a full marathon race and recovery to baseline values after just one night of rest. 6 However, NKCA increased significantly in paraplegics immediately after a wheelchair half-marathon and remained so during the next day of recreational athletics.…”

Immunoendocrine responses of male spinal cord injured athletes to 1-hour self-paced exercise: Pilot study

“…More strenuous and prolonged upper-body exercise (>60 min) has been shown to significantly decrease the number of NK cells and their cytotoxicity postexercise [19], but this compromised response did not occur in nondisabled athletes [20]. It was proposed that these differences were likely mediated by changes in cortisol [19] and prostaglandin E2 in the SCI group [20].…”

“…Previously, studies have reported increases in circulating NK cell number and cytotoxicity (part of innate immunity) in sedentary SCI individuals following electrically stimulated cycling [17] and 20 min of orthotic gait exercise [18]. More strenuous and prolonged upper-body exercise (>60 min) has been shown to significantly decrease the number of NK cells and their cytotoxicity postexercise [19], but this compromised response did not occur in nondisabled athletes [20]. It was proposed that these differences were likely mediated by changes in cortisol [19] and prostaglandin E2 in the SCI group [20].…”