ブックタイトル教育医学 J.Educ.Health Sci.　第63巻　第3号　通巻 第289号

概要

教育医学 J.Educ.Health Sci.　第63巻　第3号　通巻 第289号

Tatsuya USUI, Shintaro TSUJI, Nobuhito NAGAI and Chie TAKEYASU.Exercise (75 % VO 2 max)or restSaliva samplingBlood samplingSubjects arrivedby 12:30h0 60 120 180 (min)Rest (more than 30min)Recovery12:30 h13:00 h 14:00 h 15:00 h 16:00 hFIGURE 1 Scheme of the present studystudy, which was approved by the Ethics Committeeof Osaka Seikei College.2. Experimental designPrior to the two experimental sessions, subjectsperformed a ramp exercise test (20 W/min) usinga recumbent ergometer (Strengthergo, Mitsubishi,Tokyo, Japan) to determine the V・O 2 max after3-min rest on the ergometer and a 3-min 0 Wwarm-up, as previously described 34) . The V・O 2 maxwas measured with an AE-280S Aeromonitor(Minato Medical Science Inc., Tokyo, Japan).Ventilatory and O 2 consumption variables werecalculated using the breath-by-breath method.Subjects took part in two experimental sessions(exercise and resting conditions) at least 7days apart. The order of the two session days wasrandomized across subjects. The design of theexperimental session is shown diagrammaticallyin Figure 1. The present studies were performedduring the afternoon according to a previous studydesign 3,15) . For 24 hrs before each session, subjectswere requested to abstain from drinking caffeinebecause caffeine ingestion was reported to affectsecretion of cortisol and IgA in saliva during strenuousexercise 6) , as well as to refrain from intakeof alcohol according to a previous study design 3) .Subjects arrived at our laboratory more than 30-min before the start time of exercise testing withouthaving lunch and were asked to sit quietly inorder to avoid any physical stress before the tests.About 10-min before the exercise, a saliva samplewas collected. Immediately after the collection ofsaliva, a cannula was inserted into an antecubitalvein and a venous blood sample was taken (20 ml)by doctor. At 13:00 p.m. ( t = 0 min), the subjecteither exercised on the recumbent ergometer at75% V・O 2 max for 60 min (exercise session) or saton the recumbent ergometer while allowed to reador write quietly (resting session). After the end ofthe exercise or resting intervention, blood and salivasamples were obtained at 60 min intervals ( t= 60, 120, 180 min).3. Saliva collectionWe selected the cotton swab method ofsaliva collection 2) in order to obtain a sufficientvolume of samples for assessment of a widevariety of saliva components from untrainedvolunteers (non-athletes) who were instructedto perform the unaccustomed strenuous exercisewithout producing additional unpleasant stressby compulsory spitting. Briefly, subjects sat andrinsed out their mouths with sterilized water (30-sec×3times). Saliva induction was stimulated bychewing sterilized cotton swabs for 1 minute at afrequency of 1 chew sec -1 . Then, each subject wasasked to pull the cotton out of his mouth followed? 229 ?