15 Nippon Shokuhin Kagaku Kogaku Kaishi Vol. /., No.,, 1/ 2+ (,**1) 75 go * * R&D * Antihypertensive E#ects of GABA-Enriched Potato Snacks in Spontaneously Hypertensive Rats Toshinori Noguchi, Kazuya Nakamura, Takeshi Nagai*, Shin-ichi Katsuda* and Hidenori Koga R & D Group Research and Design Development Engineering Center, Basic research Team, Calbee Foods Co., LTD,,- 0, Kiyohara-kougyoudanchi, Utsunomiya-Shi, Tochigi -,+ -,-+ * Department of Biological Safety Research Japan Food Research Laboratories Tama Laboratory, 0 ++ +*, Nagayama, Tama-Shi, Tokyo,*0 **,/ We previously reported that gamma aminobutyric acid (GABA) was contained in potato and potato snacks. In addition, it is well known that potato contains abundant amounts of potassium. It is therefore expected that potato containing GABA and potassium will have a reductive e#ect on blood pressure. In this study, the e#ects of a single oral administration of potato snacks on blood pressure (BP) in spontaneously hypertensive rats (SHR) and normal-blood-pressure rats (WIST) were investigated. The concentrations of plasma GABA and GABA contained in potato snacks were measured by HPLC, and blood pressure was measured by the tail-cu# method. After -* minutes, plasma GABA concentration was transiently increased in GABA-enriched potato snacks as well as GABA standard solution. Moreover,. 2 hours after administration of certain types of snack product made mainly from potato (placed on the market), a significant lowering of SBP and DBP was observed in SHR, but no e#ects were observed in WIST. In contrast, a product made mainly from wheat flour (not containing GABA) had no influence on BP. Furthermore, ingestion of GABA-enriched potato snacks (+.1 mg/kg b.w.) resulted in a reduction in SBP to about -/ mmhg. These results show that GABA from potato snacks is absorbed and may be detected in plasma, and has a dose-related reductive e#ect on BP. (Received Oct. /,,**0 ; Accepted Nov.,3,,**0) Keywords : potato, GABA, blood-pressure : go --** +0 +/ 0* -* 1* + -,+ -,-+,- 0 *,*0 **,/ 0 ++ + Corresponding author t_noguchi@calbee.co.jp 2/ 3* cm +-* mmhg 2/ mmhg Ca ACE
76 /.,,**1, 16,. / 0 1 3 ACE +* ++ go g-aminobutyric acid ; GABA GABA +30+ Takahashi +, +- +. +0 +1 +2 GABA GABA +3,*,+,,,- +** g +0 0+ mg GABA +** g /* 1* mg GABA,. GABA, GABA GABA GABA + BrlHan : WIST Jlc, ; WIST + GABA 0, +, SBP DBP + +/+.. +.- g,, -+..+,.1 g, +,+.0 +.1 mmhg SBP 22.. +.2 DBP SHR Izm +, ; SHR, -,,2-..,.2 g, +12,.0 mmhg SBP +-*.* -.- mmhg DBP - -**.+ -., g, +20.+,.. mmhg SBP +,.,-, +, ; MR, GABA GABA 1/,. HPLC,/ - GABA GABA GABA 33.* GABA KINEMATICA GABA GABA GABA +,/ mg ml +** mg kg body weight b.w. WIST GABA GABA * -* 0* 3* +,* +/* - GABA,** kcal
17 : GABA 77 Table + Administration of potato- and flour-based snacks equivalent to,** kcal Amount of equivalent to,** kcal (mg/kg b. w.) (mg/ml) Dose of (ml/kg b. w.) GABA in,** kcal (mg/kg b. w.) Sample A (potato) 2**.*,* *4. Sample B (potato) 02* -.,* *4- Sample C (potato) 1,* -0,* *4, Sample D (wheat flour) + *** /*,* * Table, Intake of GABA-enriched potato snacks, including GABA concentrations GABA in potato snack (mg/g) (mg/ml) Dose of (ml/kg b. w.) Administration of GABA in potato snack (mg/kg b. w.) Sample I * +** 24- * Sample II + +** 24- *42- Sample III, +** 24- +41 GABA standard +41 *4, 24/ +41,** kcal Sample A, Sample B, Sample C Sample D Table +.,** kcal GABA SHR WIST. 2,. SBP, DBP GABA GABA GABA GABA + GABA Sample GABA Sample GABA GABA Sample Sample Sample Table, - GABA GABA GABA +.1 mg kg b.w. SHR,. 2,. SBP. BP-32A Softron tail-cuff + - / mean S.E. ANOVA ANOVA Dunett p *.*/ GABA GABA GABA -* GABA 2./ g ml, 2.* g ml +/* Fig. + GABA,0 +3 +,1 -* + GABA GABA GABA 0* GABA GABA GABA GABA GABA GABA
78 /.,,**1, 18 Fig. + Time course of plasma GABA concentration after oral administration of GABA Plasma GABA patterns after oral administration of +** mg/kg b.w. GABA-enriched potato snacks and GABA standard, respectively. Each time point represents the mean S.E. for - animals. * p *.*/ compared with the value for the GABA standard. Fig., Time course of SBP and DBP in spontaneously hypertensive rats (SHR) after administration of certain types of snack E#ect of a single oral administration of certain types of snack product made mainly from potato (Samples A, B, C) and made mainly from wheat flour (Sample D) on blood pressure in SHR. Each time point represents the mean S.E. for. animals. * p *.*/ compared with the value obtained for Sample D. GABA,.,** kcal,** kcal SHR, WIST SHR Sampl A, B. 2 SBP, DBP +/,* mmhg Fig., Sample C 2 WIST Sample A, B, C SBP, DBP Fig. - GABA Sample D SHR WIST GABA GABA GABA GABA + - g
19 : GABA 79 Fig. - Time course of SBP and DBP after administration of potato snacks in normal-blood-pressure rats (WIST) E#ect of a single oral administration of certain types of snack product made mainly from potato (Sample A, B, C) on blood pressure in WIST. Each time point represents the mean S.E. for. animals. Fig.. Time course of SBP after administration of GABA-enriched potato snack in SHR E#ect of a single oral administration of GABA-enriched potato snacks and GABA standard on blood pressure in SHR. Each time point represents the mean S.E. for. animals. * p *.*/, **p *.*+ compared with the value obtained for Sample I.,2,3 WIST WIST GABA Sample GABA +.1 mg/kg b.w. GABA GABA +.1 mg/kg b.w., 2 SBP,*.* mmhg Fig.. Sample GABA *.2- mg/kg b.w., +/ mmhg Sample GABA, Sample GABA GABA,.,. SBP GABA +/ GABA GABA B +. +/ ACE
80 /.,,**1, 20 ACE,* -* GABA SBP +2* mmhg SHR GABA GABA *.- *.2- mg kg +/ mmhg *.2- +.1 mg kg -/ mmhg 0* kg +** mg GABA GABA +* mg day -* -+ 2* mg day -, GABA GABA GABA GABA GABA,. SBP Inoue,2 -- GABA GABA GABA GABA GABA GABA -* GABA GABA, 2 GABA SHR WIST + +/,**0, Val-Tyr /- 11 2/,*** - 0 0/ 2,,**-., 2-32,**- /./ /+- /+1 +33, 0,/,+0+,+0/ +331 1 Hata, Y., Yamamoto, M., Ohni, M., Nakajima, K. and Nakamura, Y., A placebo-controlled study of the e#ects of sour milk on blood pressure in hypertensive subjects, Am. J. Cli. Nutr., 0., 101 11+ (+330). 2 /. -.1 -/.,**+ 3 VPP, IPP / // 00,**, +* + Nat. Med., /+, -3, -32 (+332). ++ Ther. Res., +2, /1* /1- (+331). +, Takahashi, H., Sumi, M. and Koshino, F., E#ect of gamma-aminobutyric acid (GABA) on normotensive or hypertensive rats and men, Jpn. J. Physiology, ++, 23 3/ (+30+). +- Billingsley, M., Suria, A., Gilman, R., Shokes, L. and Shahvari, M., Evidence for GABA involvement in the peripheral control of blood pressure and vascular resistance. Brain Res. Bull., /, -,3 --- (+32*). +. Kimura, M., Hayakawa, K. and Sansawa, H., Involvement of g-aminobutyric acid (GABA) B receptors in the hypotensive e#ect of systemically administered GABA in spontaneously hypertensive rats. Jpn. J. Pharmacol., 23, -22-3. (,**,). +/ Hayakawa, K., Kimura, M. and Kamata, K., Mechanism underlyingg-aminobutyric acid-induced antihypertensive e#ect in spontaneously hypertensive rats. Eur. J Pharmacol.,.-2, +*1 ++- (,**,). +0 Fujimura, S., Shimakage, H., Tanioka, H., Yoshida, M., Suzuki-Kusaba, M., Hisa, H. and Satoh, S., E#ects of GABA on noradrenaline release and vasoconstriction induced by renal nerve stimulation in isolated perfused rat kidney. Br. J pharmacol., +,1, +*3 ++. (+333). +1 Iovino, M., De Caro, G., Massi, M., Steardo, L. and Poenaru, S., Muscimol inhibits ADH release induced by hypertonic sodium chloride in rats. Pharmacol. Biochem. Behav., +3, --/ --2 (+32-). +2 Horn, E.M., Shonis, C.A., Holzwarth, M.A. and Waldrop,
21 : GABA 81 T.G., Decrease in glutamic acid decarboxylase level in the hypothalamus of spontaneously hypertensive rats. J. Hypertens., +0, 0,/ 0-- (+332). +3 21,/+33,* +3,-+,., +301,+ Robers, E. and Frankel, S., Gamma-Aminobutyric acid in brain : its formation from glutamic acid., J. Biol. Chem., +21, // 0- (+3/*).,, go FOOD Style,+, /, 3, 30 (,**+).,- Manyan, B., Katz, L., Hare, T.A., Gerber, J.C. and Grossman, M.H., Levels of g-aminobutyric acid in cerebral fluid in various neurogic disoiders, Arch. Neurol., -1, -/, -// (+32*).,. GABA /- /+. /+1,**0,/ Schwarz, E.L., Roberts, W.L. and Pasquali, M., Analysis of plasma amino acids by HPLC with photodiode array and fluorescence detection. Clin. Chim. Acta., -/., 2-3* (,**/).,0., /1+ /13 +3/3,1 GABA FOOD Style,+, 1, 0. 02 (,**-).,2 Inoue, K., Shirai, T., Ochiai, H., Kasao, M., Hayakawa, K., Kimura, M. and Sansawa, H., Blood-pressure-lowering e#ect of a novel fermented milk containing g-aminobutyric acid (GABA) in mild hypertensives. Euro. J. Cli. Nut., /1,.3*.3/ (,**-).,3 go.3.*3.+/,**+ -* GABA 0 /+ 0.,**- -+ GABA /+ 13 20,**. -, Matusbara, F., Ueno, H., Tadano, K., Suyama, T., Imaizumi, K. and Suzuki, K., E#ects of GABA supplementation on blood pressure and safety in adults with mild hypertension. Jpn. Pharmacol. Ther., -*, 30-31, (,**,). -- 0+ +..3 +./+ +321 +2 +* / +2 ++,3