Abstract
Adaptations of skeletal muscle morphology and metabolic enzymes were studied after prolonged training in and exposure to hypobaric (740–770 mbar) as well as normobaric conditions in rats performing treadmill running training for 10, 21 and 56 days. Animals sacrificed after 91 days served as recovery groups from training and hypobaric exposure for 56 days. The rats were divided into normobaric sedentary (NS) and training (NT) groups and hypobaric sedentary (HS) and training (HT) groups. The weights of extensor digitorum longus (EDL) and soleus (SOL) muscles increased significantly in the 56HS and the 56HT groups compared with the 56NS group, the increase being greatest in the 56HS group. No differences in the mean fibre areas (MFA) of these muscles could be seen, whereas clearly reduced MFAs of type IIA and IIB were observed in the tibialis anterior (TA) muscle. However, fibre area distribution analyses in the EDL and TA muscles showed a higher proportion of larger fibers in the 56HS and 56HT groups than in the respective normobaric groups. On the contrary, in SOL muscles the proportion of smaller fibers was higher in the hypobaric than in normobaric groups at 56 days. Increased activities of citrate synthase and β - hydroxyacyl-CoA-dehydrogenase in SOL and TA muscles in the 56HT group indicate an increase in oxidative capacity. It is concluded that exposure to, and training in moderate hypobaric conditions leads to a positive muscle protein balance which is reflected in increased muscle weights. However, the sites of increased protein synthesis and the possible hyperplasia remain to be studied further.
Similar content being viewed by others
References
Antonio J, Gonyea WJ (1993) Skeletal muscle hyperplasia. Med Sci Sports Exerc 25:1333–1345
Bedford TG, Tipton CM, Wilson NC, Oppliger RA, Gisolfi CV (1979) Maximum oxygen consumption of rats and its changes with various experimental procedures. J Appl Physiol 47:1278–1283
Beicastro AN, Wenger H (1982) Myofibril and sarcoplasmic reticulum changes with exercise and growth. Eur J Appl Physiol 49:87–95
Bergmeyer HU (1970) Methoden der enzymatischen Analyse (Vol 1). Bergmeyer HU (ed) Chemie, Weinheim, pp 404, 442-443
Bigard AX, Brunet A, Guezennec CY, Monod H (1991) Skeletal muscle changes after endurance training at high altitude. J Appl Physiol 71:2114–2121
Bigard AX, Brunet A, Guezennec CY, Monod H (1991) Effects of chronic hypoxia and endurance training on muscle capillarity in rats. Pflügers Arch 419:225–229
Boyer SJ, Blume FD (1984) Weight loss and changes in body composition at high altitude. J Appl Physiol 57:1580–1585
Bradford MM (1976) A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254
Consolazio CF, Matoush LO, Johnson HL, Daws TA (1968) Protein and water balances of young adults during prolonged exposure to high altitude (4, 300 meters). Am J Clin Nutr 21:154–161
Desplanches D, Hoppeler H, Linossier MT, Denis C, Claasen H, Dormois D, Lacour JR, Geyssant A (1993) Effects of training in normoxia and normobaric hypoxia on human muscle ultrastructure. Pflügers Arch 425:263–267
Dix DJ, Eisenberg BR (1990) Myosin mRNA accumulation and myofibrillogenesis at the myotendinous junction of stretched muscle fibers. J Cell Biol 111:1884–1894
Dubowitz V, Brooke MH (1973) Muscle biopsy: a modern approach. WB Saunders, London, pp 44–581
Esbjörnsson M, Jahnsson E, Sundberg CJ, Sylven C, Eiken O, Nygeren A, Kaijser L (1993) Muscle fibre types and enzyme activities after training with local leg ischemia in man. Acta Physiol Scand 148:233–241
Green HJ, Sutton JR, Cymerman A, Young PM, Houston CS (1989) Operation Everest II: adaptations in human skeletal muscle. J Appl Physiol 66:2454–2461
Green HJ, Jones S, Ball-Burnett M, Farrance B, Ranney D (1995) Adaptations in muscle metabolism to prolonged voluntary exercise and training. J Appl Physiol 78:138–145
Goldspink G, Howells KF (1974) Work-induced hypertrophy in exercised normal muscles of different ages and the reversibility of hypertrophy after cessation of exercise. J Physiol (Lond) 239:179–193
Goldspink D, Morton A, Loughna P, Goldspink G (1986) The effect of hypokinesia and hypodynamia on protein turnover and growth of four skeletal muscles of the rat. Pflügers Arch 407:333–340
Hayes DJ, Challis RAJ, Radda GK (1986) An investigation of arterial insufficiency in rat hindlimb. Biochem J 226:469–473
Hochachka PW, Stanley C, Sumanr-Kalnuwski J (1982) Metabolic meaning of elevated levels of oxidative enzymes in high altitude adaptive animals: an interpretive hypothesis. Respir Physiol 56:303–313
Holloszy JO (1975) Adaptation of skeletal muscle to endurance exercise. Med Sci Sports Exerc 7:155–164
Hoppeler H, Kleiner E, Schlegel C, Claassen H, Howald H, Kayar SR, Ceretelli P (1990) Morphological adaptations of human skeletal muscle to chronic hypoxia. Int J Sports Med 11 (Suppl 1):S3-S9
Kemp RG (1975) Phosphofructokinase from rabbit skeletal muscle. In: Wood WA (ed) Carbohydrate metabolism, part C. Methods in enzymology series, vol 43. Academic Press, New York, pp 71–77
Kovanen V, Suominen H (1987) Effects of age and life-time physical training on fibre composition of slow and fast skeletal muscle in rats. Pflügers Arch 408:543–551
Lynn R, Morgan DL (1994) Decline running produces more sarcomeres in rat vastus intermedius muscle fibers than does incline running. J Appl Physiol 77:1439–1444
MacDougall JD, Green HJ, Sutton JR, Coates G, Cymerman A, Young P, Houston CS (1991) Operation Everest II: structural adaptations in skeletal muscle in response to extreme simulated altitude. Acta Physiol Scand 142:421–427
Mizuno M, Juel C, Bro-Rasmussen T, Mygind E, Schibye B, Rasmussen B, Saltin B (1990) Limb skeletal muscle adaptation in athletes after training at altitude. J Appl Physiol 68:496–502
Morrison PR, Biggs RB, Booth FW (1989) Daily running for 2 wk and mRNAs for cytochrome c and α-actin in rat skeletal muscle. Am J Physiol 257: C936-C939
Nemirovskaia TL, Shenkman BS, Koshiev VB, Nekrasov AN (1993) The effect of spaced hypobaric hypoxia on the maximal hydraulic conductivity of the vascular bed, the supply of capillaries to and the size of the muscle fibers in rats (English abstract). Biull Eksp Biol Med 116:227–229
Padykula HA, Herman E (1955) The specificity of the histochemical method for adenosine triphosphatase. J Histochem Cytochem 3:170–195
Palosaari PM, Hiltunen JK (1990) Peroxisomal bifunctional protein from rat liver is a trifunctional enzyme processing 2-enoyl-CoA hydratse, 3-hydroxyacyl-CoA-dehydrogenase and △3, △2-enoyl-CoA isomerase activities. J Biol Chem 265:2446–2449
Perhonen M, Takala TES, Huttunen P, Leppäluoto J (1995) Stress hormones after prolonged physical training in normoand hypobaric conditions in rats. Int J Sports Med 16:73–77
Rose MS, Houston CS, Fulco CS, Coates G, Sutton J, Cymerman A (1988) Operation Everest II: nutrition and body composition. J Appl Physiol 65:2545–2551
Russell B, Dix DJ, Haller DL, Jacobs-El J (1992) Repair of injured skeletal muscle: a molecular approach. Med Sci Sports Exerc 24:189–196
Sillau AH, Banchero N (1977) Effects of hypoxia on capillary density and fiber composition in rat skeletal muscle. Pflügers Arch 370:227–232
Snyder GK, Aquin L, Bui MV, Byrnham N (1985) Effects of hypoxia on muscle capillarity in rats. Respir Physiol 62:135–140
Sokal RR, Rohlf FJ (1981) Biometry. WH Freeman, San Francisco, pp 441–445
Terblanche SE, Groenewald J, Linde A van der, Wolfswinkel JM, Jooste PL, Oelofsen W (1984) A comparative study of the effect of training at altitude and at sea level on endurance and certain biochemical variables. Comp Biochem Physiol 78[A]: 21–26
Terrados N, Jansson E, Sylven C, Kaijser L (1990) Is hypoxia a stimulus for synthesis of oxidative enzymes and myoglobin? J Appl Physiol 68:2369–2372
Turto H, Lindy S, Halme J (1974) Protocollagen proline hydroxylase activity in work-induced hypertrophy of rat muscle. Am J Physiol 226:63–65
White TP, Esser KA (1989) Satellite cell and growth factor involvement in skeletal muscle growth. Med Sci Sports Exer 21 (Suppl): 158–163
Yamashita H, Sato N, Yamamoto M, Gasa S, Izawa T, Komabayashi T, Ishikawa M, Sato Y, Ohno H (1993) Effect of endurance training on angiogenic activity in skeletal muscles. Pflügers Arch 422:332–338
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Perhonen, M., Takala, T.E.S. & Kovanen, V. Effects of prolonged exposure to and physical training in hypobaric conditions on skeletal muscle morphology and metabolic enzymes in rats. Pflügers Arch — Eur J Physiol 432, 50–58 (1996). https://doi.org/10.1007/s004240050104
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s004240050104