A novel, noninvasive transdermal fluid sampling methodology: IGF-I measurement following exercise

2011 ◽  
Vol 300 (6) ◽  
pp. R1326-R1332 ◽  
Author(s):  
D. E. Scofield ◽  
H. L. McClung ◽  
J. P. McClung ◽  
W. J. Kraemer ◽  
K. R. Rarick ◽  
...  

This study tested the hypothesis that transdermal fluid (TDF) provides a more sensitive and accurate measure of exercise-induced increases in insulin-like growth factor-I (IGF-I) than serum, and that these increases are detectable proximal, but not distal, to the exercising muscle. A novel, noninvasive methodology was used to collect TDF, followed by sampling of total IGF-I (tIGF-I) and free IGF-I (fIGF-I) in TDF and serum following an acute bout of exercise. Experiment 1: eight men (23 ± 3 yrs, 79 ± 7 kg) underwent two conditions (resting and 60 min of cycling exercise at 60% V̇o2peak) in which serum and forearm TDF were collected for comparison. There were no significant changes in tIGF-I or fIGF-I in TDF obtained from the forearm or from serum following exercise ( P > 0.05); however, the proportion of fIGF-I to tIGF-I in TDF was approximately fourfold greater than that of serum ( P ≤ 0.05). These data suggest that changes in TDF IGF-I are not evident when TDF is sampled distal from the working tissue. To determine whether exercise-induced increases in local IGF-I could be detected when TDF was sampled directly over the active muscle group, we performed a second experiment. Experiment 2: fourteen subjects (22 ± 4 yr, 68 ± 11 kg) underwent an acute plyometric exercise condition consisting of 10 sets of 10 plyometric jumps with 2-min rest between sets. We observed a significant increase in TDF tIGF-I following exercise ( P ≤ 0.05) but no change in serum tIGF-I ( P > 0.05). Overall, these data suggest that TDF may provide a noninvasive means of monitoring acute exercise-induced changes in local IGF-I when sampled in proximity to exercising muscles. Moreover, our finding that the proportion of free to tIGF-I was greater in TDF than in serum suggests that changes in local IGF-I may be captured more readily using this system.

2012 ◽  
Vol 303 (10) ◽  
pp. R1080-R1089 ◽  
Author(s):  
Bradley C. Nindl ◽  
Maria L. Urso ◽  
Joseph R. Pierce ◽  
Dennis E. Scofield ◽  
Brian R. Barnes ◽  
...  

Insulin-like growth factor-I (IGF-I) resides across different biocompartments [blood, interstitial fluid (ISF), and muscle]. Whether circulating IGF-I responses to exercise reflect local events remains uncertain. We measured the IGF-I response to plyometric exercise across blood, ISF, and muscle biopsy from the vastus lateralis. Twenty volunteers (8 men, 12 women, 22 ± 1 yr) performed 10 sets of 10 plyometric jump repetitions at a 40% 1-repetition maximum. Blood, ISF, and muscle samples were taken pre- and postexercise. Circulating IGF-I increased postexercise: total IGF-I (preexercise = 546 ± 42, midexercise = 585 ± 43, postexercise = 597 ± 45, +30 = 557 ± 42, +60 = 536 ± 40, +120 = 567 ± 42 ng/ml; midexercise, postexercise, and +120 greater than preexercise, P < 0.05); Free IGF-I (preexercise = 0.83 ± 0.09, midexercise = 0.78 ± 0.10, postexercise = 0.79 ± 0.11, +30 = 0.93 ± 0.10, +60 = 0.88 ± 0.10, + 120 = 0.91 ± 0.11 ng/ml; +30 greater than all other preceding time points, P < 0.05). No exercise-induced changes were observed for ISF IGF-I (preexercise = 2.35 ± 0.29, postexercise = 2.46 ± 0.35 ng/ml). No changes were observed for skeletal muscle IGF-I protein, although IGF-I mRNA content increased ∼40% postexercise. The increase in circulating total and free IGF-I was not correlated with increases in ISF IGF-I or muscle IGF-I protein content. Our data indicate that exercise-induced increases in circulating IGF-I are not reflective of local IGF-I signaling.


2021 ◽  
Author(s):  
Sarah Ahmad ◽  
Rodney Hansen ◽  
Matthew Schmolesky

AbstractResearch suggests strong inter-relationships between physical exercise, levels of brain-derived neurotrophic factor (BDNF), levels of estrogen, and the menstrual cycle, and yet no single study has examined these factors collectively in humans. The current study assessed the effect of an acute bout of vigorous aerobic exercise (20 minutes of stationary cycling at 80% of heart rate reserve) on serum BDNF and estradiol in healthy, eumenorrheic women, ages 18-28. In addition, this study determined whether basal BDNF or the exercise-induced increase in BDNF varies throughout the menstrual cycle. Thirty-four subjects were assigned to an experimental (n = 27) or control condition (n = 7). Exercise transiently increased both estradiol (51.2%) and BDNF (23.6%), and basal levels of BDNF and estradiol predicted the magnitude of the exercise-induced increases. Basal BDNF did not vary significantly throughout the menstrual cycle. Exercise-induced changes in BDNF did not correlate with menstrual cycle day or basal estradiol. Basal estradiol and basal BDNF showed a marginally significant positive correlation. Taken together, these results indicate that brief, vigorous aerobic exercise is sufficient to elevate both BDNF and estradiol in healthy women and that the menstrual cycle dramatically influences the magnitude of exercise-induced changes in estradiol, but not BDNF


2014 ◽  
Vol 6 (2) ◽  
pp. 29-34
Author(s):  
Nirmala Limbu ◽  
Ramanjan Sinha ◽  
Meenakshi Sinha ◽  
Bishnu Hari Paudel

Objective: We aimed to investigate how EEG frequency bands change in females in response to acute exercise compared to males.Methods: Consenting healthy adult females (n=15) & males (n=15) bicycled an ergometer at 50% HRmax for 20 min. EEG was recorded using 10-20 system from mid-frontal (F4 & F3), central (C4 & C3), parietal (P4 & P3), temporal (T4 & T3) & occipital (O2 & O1) regions. Exercise-induced EEG changes were compared between two sexes by Mann Whitney test. EEG power (μV2) is presented as median & interquartile range.Results: In females, as compared to males, resting right side delta, alpha, and beta activities were more in almost all recorded sites [delta: F4= 49.82 (44.23-63.56) vs. 35.5 (32.70-44.44), p < 0.001; etc], [alpha F4: 127.62 (112.89-149.03) vs. 49.36 (46.37-52.98), p < 0.001; etc], [beta F4= 18.96 (15.83-25.38)  vs. 14.77 (10.34-17.55), p < 0.05; C4= 21.16 (18.4-25.9) vs. 15.48 (9.66-19.40), p < 0.01; etc]. Similarly, females resting right theta activity was more in parietal [P4= 33.04 (25.1-42.41) vs. 22.3 (18.36-34.33), p < 0.05] & occipital [O2= 50.81 (30.64-66.8) vs. 26.85 (22.18-34.42), p < 0.001] regions than in males. They had similar picture on the left side also. The delta values of right alpha power was less in female in frontal [F4= -11.61 (-45.24 -3.64) vs. 9.48 (1.05-16.58), p < 0.01] and central [C4= -72 (-32.98-9.48) vs. 22.69 (13.03-33.05), p < 0.01] regions compared to males. Also, they had less delta values of left central alpha [C3= -8.32 (-32.65-6.1) vs. 16.5 (0.36-36.36), p < 0.01] and temporal beta [T3= -6.29 (-10.09- -1.49) vs. 1.24 (-0.84- 2.8), p < 0.001] power compared to males.Conclusion: At rest females may have high EEG powers in different bands. In response to acute exercise, they respond in reverse way as compared to males.DOI: http://dx.doi.org/10.3126/ajms.v6i2.11116Asian Journal of Medical Sciences Vol.6(2) 2015 30-35


1986 ◽  
Vol 60 (3) ◽  
pp. 986-990 ◽  
Author(s):  
M. E. Wheeler ◽  
G. L. Davis ◽  
W. J. Gillespie ◽  
M. M. Bern

Acute exercise enhances fibrinolytic (FA), factor VIII coagulant and factor VIII ristocetin cofactor activities, and increases the concentration of factor VIII-related antigen. Little is known concerning the mechanisms of these changes. To investigate possible relationships between exercise-induced changes in blood lactate, 2,3-diphosphoglycerate (DPG), and the hemostatic variables, a branching multistage treadmill protocol was used to exercise male volunteers to a maximum effort. Blood samples were drawn before, immediately post-, and 8 min postexercise. All hemostatic variables were significantly (P less than 0.05) increased postexercise. Highest values for factor VIII coagulant, factor VIII-related antigens and factor VIII ristocetin cofactor were observed at 8 min postexercise. Significant (P less than 0.001) correlations were found postexercise for lactate with factor VIII coagulant (r = 0.64), while no association between pre-, post-, or 8 min postexercise. Postexercise lactate demonstrated a significant correlation (r = +0.81), which was strengthened by including the preexercise high-density lipoprotein (HDL) concentrations (r = +0.87). Consequently, the expected postexercise FA may be calculated from the observed values for postexercise lactate and preexercise HDL. The correlations of lactate with postexercise FA and with postexercise factor VIII coagulant may reflect a common stimulus for these exercise-induced changes.


1997 ◽  
Vol 272 (5) ◽  
pp. G1100-G1108 ◽  
Author(s):  
C. A. Peterson ◽  
H. V. Carey ◽  
P. L. Hinton ◽  
H. C. Lo ◽  
D. M. Ney

Growth hormone (GH) action is primarily mediated by insulin-like growth factor I (IGF-I), although both growth factors show tissue-selective effects. We investigated the effects of GH, IGF-I, and GH plus IGF-I on jejunal growth and function in rats maintained with total parenteral nutrition (TPN) and given recombinant human GH (rhGH) (400 micrograms/day sc, twice daily) and/or rhIGF-I (800 micrograms/day in TPN solution) for 5 days. Administration of GH or IGF-I alone produced similar increases in serum IGF-I levels and body weight; GH plus IGF-I further increased these parameters. TPN reduced mucosal mass, protein and DNA content, villus height, crypt depth, and enterocyte migration rate. IGF-I or GH plus IGF-I produced equivalent increases in all intestinal growth parameters; GH alone had no effect. GH, IGF-I, or GH plus IGF-I reduced TPN-induced increases in sucrase-specific activity. IGF-I, but not GH, attenuated TPN-induced increases in tissue conductance and carbachol-stimulated ion secretion. In contrast to IGF-I, GH does not stimulate intestinal growth during TPN and has less effect on normalizing TPN-induced changes in epithelial function.


2014 ◽  
Vol 99 (9) ◽  
pp. 1253-1264 ◽  
Author(s):  
Tim H. A. Schreuder ◽  
Jaap H. van Lotringen ◽  
Maria T. E. Hopman ◽  
Dick H. J. Thijssen

Sign in / Sign up

Export Citation Format

Share Document