Aims: This study was designed to explore the plasma oxytocin (OT) response to exercise until exhaustion in trained male cyclists. Methods: Twelve professional cyclists (EXP group; age: 26 ± 2 years; VO2max: 4,804 ± 549 ml) and 10 sedentary young men (CONT group; age: 23 ± 2 years; VO2max: 3,146 ± 602 ml) performed a maximal incremental exercise test on a cycle ergometer. Evaluation was made of the oxygen uptake (VO2) and concentrations of blood lactate and plasma OT immediately before, during and immediately after the tests, respectively. Results: Significant increases (p < 0.01) related to exercise were recorded in VO2 and lactate concentration within each group, while no such changes were observed in OT levels. OT values, on the other hand, were significantly lower (p < 0.01) in EXP than in CONT throughout the tests. Conclusion: It was concluded that plasma OT shows no response to graded exercise until exhaustion in professional cyclists.

1.
Jenkins JS, Nussey SS: The role of oxytocin: Present concepts. Clin Endocrinol 1991;34:515–525.
2.
Buijs RM: Vasopressin and oxytocin: Their role in neurotransmission. Pharmacol Ther 1983;22:127–141.
3.
Jezova D, Skultetyova I, Tokarev DI, Bakos P, Vigas M: Vasopressin and oxytocin in stress. Ann NY Acad Sci 1995;771P:192–203.
4.
Murray RG, Hackney AC: Endocrine responses to exercise and training; in Garrett WE Jr, Kirkendall DT (eds): Exercise and Sport Science. Philadelphia, Lippincott Williams & Wilkins, 2000, pp 135–161.
5.
Viru A: Plasma hormones and physical exercise. Int J Sports Med 1992;13:201–209.
6.
Deuster PA, Chrousos GP, Luger A, De Bolt JE, Bernier LL, Trostmann UH, Kyle SB, Montgomery LC, Loriaux DL: Hormonal and metabolic responses of untrained, moderately trained, and highly trained men to three exercise intensities. Metabolism 1989;38:141–148.
7.
Christensen NJ, Galbo H, Hansen JF, Hesse B, Richter EA, Trap-Jensen J: Catecholamines and exercise. Diabetes 1979;28:58–62.
8.
McMurray RG, Forsythe WA, Mar MH, Hardy CJ: Exercise intensity-related responses of β-endorphins and catecholamines. Med Sci Sports Exerc 1987;19:570–574.
9.
Kindermann W, Schnabel A, Schmitt WM, Biro G, Cassens J, Weber F: Catecholamines, growth hormone, cortisol, insulin, and sex hormones in anaerobic and aerobic exercise. Eur J Appl Physiol 1982;49:389–399.
10.
Hale RW, Kosana T, Krieger J, Pepper S: A marathon: The immediate effect on female runners’ luteinizing hormone, follicle-stimulating hormone, prolactin, testosterone, and cortisol levels. Am J Obstet Gynecol 1983;146:550–556.
11.
Montain SJ, Laird JE, Latzka WA, Sawaka MN: Aldosterone and vasopressin responses in the heat: Hydration level and exercise intensity effects. Med Sci Sports Exerc 1997;29:661–668.
12.
Convertino VA, Keil LE, Bernauer EM, Greenleaf JE: Plasma volume, osmolality, vasopressin and renin activity during graded exercise in man. J Appl Physiol 1981;50:123–128.
13.
Grant SM, Green HJ, Phillips SM, Enns DL, Sutton JR: Fluid and electrolyte hormonal responses to exercise and acute plasma volume expansion. J Appl Physiol 1996;81:2386–2392.
14.
Greenleaf JE, Brock PJ, Keil LC, Morse JT: Drinking and water balance during exercise and heat acclimation. J Appl Physiol 1983;54:414–419.
15.
Altemus M, Deuster PA, Galliven E, Carter CS, Gold W: Suppression of hypothalamic-pituitary-adrenal axis responses to stress in lactating women. J Clin Endocrinol Metab 1995;80:2954–2959.
16.
Landgraf R, Häcker R, Buhl H: Plasma vasopressin and oxytocin in response to exercise and during a day-night cycle in man. Endokrinologie 1982;79:281–291.
17.
Lucia A, Pardo J, Durántez A, Hoyos J, Chicharro JL: Physiological differences between professional and elite road cyclists. Int J Sports Med 1998;19:342–348.
18.
American College of Sports Medicine (ACSM): Guidelines for Exercise Testing and Prescription. Philadelphia, Lea & Febiger, 1986, pp 95–96.
19.
Weltman AD, Snead D, Seip R, Schurrer R, Levine S, Rutt R: Reliability and validity of a continuous incremental treadmill protocol for the determination of lactate threshold, fixed blood lactate concentration, and VO2max. Int J Sports Med 1990;11:26–32.
20.
Dill DB, Costill DL: Calculation of percentage changes in volume of blood plasma and red cells in dehydration. J Appl Physiol 1974;37:247–248.
21.
Convertino VA, Keil LC, Greenleaf JE: Plasma volume, renin, and vasopressin responses to graded exercise after training. J Appl Physiol 1983;54:508–514.
22.
Melin B, Eclache JP, Geelen G, Annat G, Allevard AM, Jarsaillon E, Zebidi A, Legros JJ, Gharib C: Plasma AVP, neurophysin, renin activity, and aldosterone during submaximal exercise performed until exhaustion in trained and untrained men. Eur J Appl Physiol 1980;44:141–151.
23.
Luger A, Deuster P, Kyle SB, Gallucci WT, Montgomery LC, Gold PW, Loriaux DL, Chrousos GP: Acute hypothalamic-pituitary-adrenal responses to the stress of treadmill exercise. N Engl J Med 1987;316:1309–1315.
24.
Mazzeo RS, Marshall P: Influence of plasma catecholamines on the lactate threshold during graded exercise. J Appl Physiol 1989;67:1319–1322.
25.
Li J, Hand GA, Potts JT, Mitchell JH: Identification of hypothalamic vasopressin and oxytocin neurons activated during the exercise pressor reflex in cats. Brain Res 1997;752:45–51.
26.
Stebbins ChL, Ortiz-Acebedo A: The exercise pressor reflex is attenuated by intrathecal oxytocin. Am J Physiol 1994;267:R909–R1015.
27.
Coiro V, Passeri M, Davoli C, Bacchi-Modena A, Bianconi L, Volpi R, Chiodera P: Oxytocin reduces exercise-induced ACTH and cortisol rise in man. Acta Endocrinol (Copenh) 1988;119:405–412.
28.
Johnson HM, Torres BA: Regulation of lymphokine production by arginine vasopressin and oxytocin: Modulation of lymphocyte function by neurohypophyseal hormones. J Immunol 1985;135:773–775.
29.
Whitton PD, Rodrigues LM, Hems DA: Stimulation by vasopressin, angiotensin, and oxytocin of gluconeogenesis in hepatocyte suspensions. Biochem J 1978;176:893–898.
30.
Nakano J, Fisher RD: Studies on the cardiovascular effects of synthetic oxytocin. J Pharmacol Exp Ther 1963;142:206–214.
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