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Hymer WC, Kraemer WJ. Resistance exercise stress: theoretical mechanisms for growth hormone processing and release from the anterior pituitary somatotroph. Eur J Appl Physiol 2023; 123:1867-1878. [PMID: 37421488 DOI: 10.1007/s00421-023-05263-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 06/15/2023] [Indexed: 07/10/2023]
Abstract
Heavy resistance exercise (HRE) is the most effective method for inducing muscular hypertrophy and stimulating anabolic hormones, including growth hormone, into the blood. In this review, we explore possible mechanisms within the GH secretory pathway of the pituitary somatotroph, which are likely to modulate the flow of hormone synthesis and packaging as it is processed prior to exocytosis. Special emphasis is placed on the secretory granule and its possible role as a signaling hub. We also review data that summarize how HRE affects the quality and quantity of the secreted hormone. Finally, these pathway mechanisms are considered in the context of heterogeneity of the somatotroph population in the anterior pituitary.
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Affiliation(s)
- Wesley C Hymer
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - William J Kraemer
- Department of Human Sciences, The Ohio State University, Columbus, OH, 43802, USA.
- Department of Kinesiology, University of Connecticut, Storrs, CT, USA.
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA.
- School of Medical and Health Sciences, Edith Cowan University, Perth, Australia.
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Paragliola RM, Carrozza C, Corsello SM, Salvatori R. The biochemical diagnosis of acromegaly: revising the role of measurement of IGF-I and GH after glucose load in 5 questions. Expert Rev Endocrinol Metab 2022; 17:205-224. [PMID: 35485763 DOI: 10.1080/17446651.2022.2069558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/20/2022] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Acromegaly is a rare disorder characterized by the excessive secretion of growth hormone (GH), mostly caused by pituitary adenomas. While in full-blown cases the diagnosis is easy to establish, milder cases are more challenging. Additionally, establishing whether full cure after surgery is reached may be difficult. AREAS COVERED In this article, we will review the challenges posed by the variability in measurements of GH and its main effector insulin-like growth factor I (IGF-I) due to both biological changes, co-morbidities, and assays variability. EXPERT OPINION Interpretation of GH and IGF-I assays is important in establishing an early diagnosis of acromegaly, in avoiding misdiagnosis, and in establishing if cure is achieved by surgery. Physicians should be familiar with the variables that affect measurements of these 2 hormones, and with the performance of the assays available in their practice.
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Affiliation(s)
- Rosa Maria Paragliola
- Unit of Endocrinology, Department of Translational Medicine and Surgery - Universita' Cattolica del Sacro Cuore, Fondazione Policlinico "Gemelli", IRCCS, Rome, Italy
| | - Cinzia Carrozza
- Unit of Chemistry, Biochemistry and Clinical Molecular Biology - Università Cattolica Del Sacro Cuore, Fondazione Policlinico "Gemelli," IRCCS, Rome, Italy
| | - Salvatore M Corsello
- Unit of Endocrinology, Department of Translational Medicine and Surgery - Universita' Cattolica del Sacro Cuore, Fondazione Policlinico "Gemelli", IRCCS, Rome, Italy
- UniCamillus-Saint Camillus International University of Health Sciences, Rome, Italy
| | - Roberto Salvatori
- Division of Endocrinology Diabetes and Metabolism and Pituitary Center, Johns Hopkins University, Baltimore MD, USA
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Hatfield DL, Kraemer WJ, Volek JS, Nindl BC, Caldwell LK, Vingren JL, Newton RU, Häkkinen K, Lee EC, Maresh CM, Hymer WC. Hormonal stress responses of growth hormone and insulin-like growth factor-I in highly resistance trained women and men. Growth Horm IGF Res 2021; 59:101407. [PMID: 34118743 DOI: 10.1016/j.ghir.2021.101407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 05/10/2021] [Accepted: 05/13/2021] [Indexed: 10/21/2022]
Abstract
The purpose of this study was to examine the responses of growth hormone (GH) and insulin-like growth factor-I (IGFI) to intense heavy resistance exercise in highly trained men and women to determine what sex-dependent responses may exist. Subjects were highly resistance trained men (N = 8, Mean ± SD; age, yrs., 21 ± 1, height, cm, 175.3 ± 6.7, body mass, kg, 87.0 ± 18.5, % body fat, 15.2 ± 5.4, squat X body mass, 2.1 ± 0.4; and women (N = 7; Mean ± SD, age, yrs. 24 ± 5, height, cm 164.6 ± 6.7, body mass, kg 76.4 ± 8.8, % body fat, 26.9 ± 5.3, squat X body mass, 1.7 ± 0.6). An acute resistance exercise test protocol (ARET) consisted of 6 sets of 10 repetitions at 80% of the 1 RM with 2 min rest between sets was used as the stressor. Blood samples were obtained pre-exercise, after 3 sets, and then immediately after exercise (IP), 5, 15, 30, and 70 min post-exercise for determination of blood lactate (HLa), and plasma glucose, insulin, cortisol, and GH. Determination of plasma concentrations of IGFI, IGF binding proteins 1, 2, and 3 along with molecular weight isoform factions were determined at pre, IP and 70 min. GH significantly (P ≤ 0.05) increased at all time points with resting concentrations significantly higher in women. Significant increases were observed for HLa, glucose, insulin, and cortisol with exercise and into recovery with no sex-dependent observations. Women showed IGF-I values that were higher than men at all times points with both seeing exercise increases. IGFBP-1 and 2 showed increase with exercise with no sex-dependent differences. IGFBP-3 concentrations were higher in women at all-time points with no exercise induced changes. Both women and men saw an exercise induced increase with significantly higher values in GH in only the mid-range (30-60 kD) isoform. Only women saw an exercise induced increase with significantly higher values for IGF fractions only in the mid-range (30-60 kD) isoform, which were significantly greater than the men at the IP and 70 min post-exercise time points. In conclusion, the salient findings of this investigation were that in highly resistance trained men and women, sexual dimorphisms exist but appear different from our prior work in untrained men and women and appear to support a sexual dimorphism related to compensatory aspects in women for anabolic mediating mechanisms in cellular interactions.
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Affiliation(s)
- Disa L Hatfield
- Human Performance Laboratory, Department of Kinesiology, University of Rhode Island Kingston, RI 02881, USA
| | - William J Kraemer
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA.
| | - Jeff S Volek
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Bradley C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Lydia K Caldwell
- Applied Physiology Laboratory, University of North Texas, Denton, TX, USA
| | - Jakob L Vingren
- Applied Physiology Laboratory, University of North Texas, Denton, TX, USA
| | - Robert U Newton
- Exercise Medicine Research Institute, Edith Cowan University, Joondalup, WA 6027, Australia
| | - Keijo Häkkinen
- Neuromuscular Research Center, Biology of Physical Activity, University of Jyväskylä, Finland
| | - Elaine C Lee
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA
| | - Carl M Maresh
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Wesley C Hymer
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
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Kraemer WJ, Caldwell LK, Post EM, Beeler MK, Dickerson RM, Kennett MJ, Volek JS, Maresh CM, Hymer WC. Recovery using "float" from high intensity stress on growth hormone-like molecules in resistance trained men. Growth Horm IGF Res 2020; 55:101355. [PMID: 33032163 DOI: 10.1016/j.ghir.2020.101355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/27/2020] [Accepted: 08/30/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The purpose of this study was to examine the influence of a novel "floatation-restricted environmental stimulation therapy" (floatation-REST) on growth hormone responses to an intense resistance exercise stress. DESIGN Nine resistance trained men (age: 23.4 ± 2.5 yrs.; height: 175.3 ± 5.4 cm; body mass: 85.3 ± 7.9 kg) completed a balanced, crossover-controlled study design with two identical exercise trials, differing only in post-exercise recovery intervention (i.e., control or floatation-REST). A two-week washout period was used between experimental conditions. Plasma lactate was measured pre-exercise, immediately post-exercise and after the 1 h. recovery interventions. Plasma iGH was measured pre-exercise, immediately-post exercise, and after the recovery intervention, as well as 24 h and 48 h after the exercise test. The bGH-L was measured only at pre-exercise and following each recovery intervention. RESULTS For both experimental conditions, a significant (P ≤ 0.05) increase in lactate concentrations were observed immediately post-exercise (~14 mmol • L-1) and remained slightly elevated after the recovery condition. The same pattern of responses was observed for iGH with no differences from resting values at 24 and 48 h of recovery. The bGH-L showed no exercise-induced changes following recovery with either treatment condition, however concentration values were dramatically lower than ever reported. CONCLUSION The use of floatation-REST therapy immediately following intense resistance exercise does not appear to influence anterior pituitary function in highly resistance trained men. However, the lower values of bGH suggest dramatically different molecular processing mechanisms at work in this highly trained population.
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Affiliation(s)
- William J Kraemer
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America.
| | - Lydia K Caldwell
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America
| | - Emily M Post
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America
| | - Matthew K Beeler
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America
| | - Ryan M Dickerson
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America
| | - Mary J Kennett
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Jeff S Volek
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America
| | - Carl M Maresh
- Department of Human Sciences, The Ohio State University, Columbus, OH 43210, United States of America
| | - Wesley C Hymer
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America
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Merrigan JJ, Tufano JJ, Fields JB, Oliver JM, Jones MT. Rest Redistribution Does Not Alter Hormone Responses in Resistance-Trained Women. J Strength Cond Res 2020; 34:1867-1874. [PMID: 32598121 DOI: 10.1519/jsc.0000000000003617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Merrigan, JJ, Tufano, JJ, Fields, JB, Oliver, JM, and Jones, MT. Rest redistribution does not alter hormone responses in resistance-trained women. J Strength Cond Res 34(7): 1867-1874, 2020-The purpose was to examine acute effects of rest redistribution (RR) on perceptual, metabolic, and hormonal responses during back squats. Twelve resistance-trained women (training age 5 ± 2 years; one repetition maximum [1-RM] per body mass, 1.6 ± 0.2) performed traditional (TS, 4 sets of 10 repetitions with 120 seconds interset rest) and RR sets (4 sets of two 5 repetition clusters with 30-second intraset rest and 90-second interset rest) in counterbalanced order, separated by 72 hours. Both conditions were performed at 70% 1RM with 360 seconds of total rest. Ratings of perceived exertion (RPE) were taken after each set. Blood was sampled at baseline, after each set, and at 5, 15, 30, and 60 minutes, as well as 24 and 48 hours after training. Alpha level was p ≤ 0.05. The RPE progressively increased throughout both conditions (p = 0.002) with a greater overall mean for TS (5.81 ± 0.14) than RR (4.71 ± 0.14; p = 0.003). Lactate increased above baseline and remained elevated through 15 minutes post in both conditions (4.00 ± 0.76; p = 0.001), with greater lactate levels for TS (6.33 ± 0.47) than RR (4.71 ± 0.53; p < 0.001). Total testosterone was elevated after set 2 (0.125 ± 0.02; p = 0.011), but no other time point, while free testosterone remained unchanged. Growth hormone continually rose from baseline to set 3 and returned to baseline by 60 minutes post (20.58 ± 3.19). Cortisol and creatine kinase did not change over time. No condition × time interactions existed for any hormone (p > 0.05). Use of rest redistribution resulted in lower perceived effort and lactate responses. Yet, hormone responses during rest redistribution were no different from TS.
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Affiliation(s)
- Justin J Merrigan
- Frank Pettrone Center for Sports Performance, George Mason University, Fairfax, Virginia.,Kinesiology, George Mason University, Manassas, Virginia
| | - James J Tufano
- Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic; and
| | - Jennifer B Fields
- Frank Pettrone Center for Sports Performance, George Mason University, Fairfax, Virginia.,Kinesiology, George Mason University, Manassas, Virginia
| | - Jonathan M Oliver
- Army West Point Athletics, United States Military Academy, West Point, New York
| | - Margaret T Jones
- Frank Pettrone Center for Sports Performance, George Mason University, Fairfax, Virginia.,Kinesiology, George Mason University, Manassas, Virginia
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Caloric restriction induces anabolic resistance to resistance exercise. Eur J Appl Physiol 2020; 120:1155-1164. [PMID: 32236752 PMCID: PMC8233264 DOI: 10.1007/s00421-020-04354-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/21/2020] [Indexed: 12/21/2022]
Abstract
Purpose Weight loss can result in the loss of muscle mass and bone mineral density. Resistance exercise is commonly prescribed to attenuate these effects. However, the anabolic endocrine response to resistance exercise during caloric restriction has not been characterized. Methods Participants underwent 3-day conditions of caloric restriction (15 kcal kg FFM−1) with post-exercise carbohydrate (CRC) and with post-exercise protein (CRP), and an energy balance control (40 kcal kg FFM−1) with post-exercise carbohydrate (CON). Serial blood draws were taken following five sets of five repetitions of the barbell back squat exercise on day 3 of each condition. Results In CRC and CRP, respectively, growth hormone peaked at 2.6 ± 0.4 and 2.5 ± 0.9 times the peak concentrations observed during CON. Despite this, insulin-like growth factor-1 concentrations declined 18.3 ± 3.4% in CRC and 27.2 ± 3.8% in CRP, which was greater than the 7.6 ± 3.6% decline in CON, over the subsequent 24 h. Sclerostin increased over the first 2 days of each intervention by 19.2 ± 5.6% in CRC, 21.8 ± 6.2% in CRP and 13.4 ± 5.9% in CON, but following the resistance exercise bout, these increases were attenuated and no longer significant. Conclusion During caloric restriction, there is considerable endocrine anabolic resistance to a single bout of resistance exercise which persists in the presence of post-exercise whey protein supplementation. Alternative strategies to restore the sensitivity of insulin-like growth factor-1 to growth hormone need to be explored. Electronic supplementary material The online version of this article (10.1007/s00421-020-04354-0) contains supplementary material, which is available to authorized users.
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Kraemer WJ, Ratamess NA, Hymer WC, Nindl BC, Fragala MS. Growth Hormone(s), Testosterone, Insulin-Like Growth Factors, and Cortisol: Roles and Integration for Cellular Development and Growth With Exercise. Front Endocrinol (Lausanne) 2020; 11:33. [PMID: 32158429 PMCID: PMC7052063 DOI: 10.3389/fendo.2020.00033] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/16/2020] [Indexed: 12/16/2022] Open
Abstract
Hormones are largely responsible for the integrated communication of several physiological systems responsible for modulating cellular growth and development. Although the specific hormonal influence must be considered within the context of the entire endocrine system and its relationship with other physiological systems, three key hormones are considered the "anabolic giants" in cellular growth and repair: testosterone, the growth hormone superfamily, and the insulin-like growth factor (IGF) superfamily. In addition to these anabolic hormones, glucocorticoids, mainly cortisol must also be considered because of their profound opposing influence on human skeletal muscle anabolism in many instances. This review presents emerging research on: (1) Testosterone signaling pathways, responses, and adaptations to resistance training; (2) Growth hormone: presents new complexity with exercise stress; (3) Current perspectives on IGF-I and physiological adaptations and complexity these hormones as related to training; and (4) Glucocorticoid roles in integrated communication for anabolic/catabolic signaling. Specifically, the review describes (1) Testosterone as the primary anabolic hormone, with an anabolic influence largely dictated primarily by genomic and possible non-genomic signaling, satellite cell activation, interaction with other anabolic signaling pathways, upregulation or downregulation of the androgen receptor, and potential roles in co-activators and transcriptional activity; (2) Differential influences of growth hormones depending on the "type" of the hormone being assayed and the magnitude of the physiological stress; (3) The exquisite regulation of IGF-1 by a family of binding proteins (IGFBPs 1-6), which can either stimulate or inhibit biological action depending on binding; and (4) Circadian patterning and newly discovered variants of glucocorticoid isoforms largely dictating glucocorticoid sensitivity and catabolic, muscle sparing, or pathological influence. The downstream integrated anabolic and catabolic mechanisms of these hormones not only affect the ability of skeletal muscle to generate force; they also have implications for pharmaceutical treatments, aging, and prevalent chronic conditions such as metabolic syndrome, insulin resistance, and hypertension. Thus, advances in our understanding of hormones that impact anabolic: catabolic processes have relevance for athletes and the general population, alike.
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Affiliation(s)
- William J. Kraemer
- Department of Human Sciences, The Ohio State University, Columbus, OH, United States
- *Correspondence: William J. Kraemer
| | - Nicholas A. Ratamess
- Department of Health and Exercise Science, The College of New Jersey, Ewing, NJ, United States
| | - Wesley C. Hymer
- Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States
| | - Bradley C. Nindl
- Department of Sports Medicine, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States
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