UPTAKE AND HYDROLYSIS OF GLYCYLGLUTAMINE AT THE BLOOD-BRAIN-BARRIER

被引:8
作者
VAZQUEZ, JA
RAGHUNATH, M
ADIBI, SA
机构
[1] UNIV PITTSBURGH,MONTEFIORE HOSP,CLIN NUTR UNIT,3459 5TH AVE,PITTSBURGH,PA 15213
[2] UNIV PITTSBURGH,SCH MED,DEPT MED,PITTSBURGH,PA 15261
来源
METABOLISM-CLINICAL AND EXPERIMENTAL | 1992年 / 41卷 / 02期
关键词
D O I
10.1016/0026-0495(92)90137-Y
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Using an organ balance technique in dogs, we recently found that liver, skeletal muscle, kidney, and intestine participate in clearance of glycylglutamine from plasma. The purpose of the present study was to investigate whether brain does the same. The study of arteriovenous differences of glycylglutamine across brain, during continuous infusion of this dipeptide (12 μmol · min-1 · kg-1) in dogs, showed an arteriovenous difference that was never significantly different from zero. To establish a basis for this lack of clearance, we investigated uptake and hydrolysis of glycylgutamine at the blood-brain barrier. The study of brain uptake index of glycylglutamine in rats showed that it was not significantly different from that of sucrose, an impermeable marker (3.2 ± 0.4 v 3.5 ± 0.4, n = 4 to 5). When isolated brain capillaries were incubated with glycylglutamine, uptake was only modestly above background activity and appeared to be due to nonspecific binding. Finally, the plasma membrane of brain capillaries lacked hydrolase activity against glycylglutamine. In conclusion, brain appears to be unique among organs in lacking any mechanism for clearance of glycylglutamine from plasma. © 1992.
引用
收藏
页码:121 / 124
页数:4
相关论文
共 23 条
  • [1] POSSIBLE SOURCES OF GLUTAMINE FOR PARENTERAL-NUTRITION - IMPACT ON GLUTAMINE-METABOLISM
    ABUMRAD, NN
    MORSE, EL
    LOCHS, H
    WILLIAMS, PE
    ADIBI, SA
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1989, 257 (02): : E228 - E234
  • [2] INTRAVENOUS USE OF GLUTAMINE IN PEPTIDE FORM - CLINICAL-APPLICATIONS OF OLD AND NEW OBSERVATIONS
    ADIBI, SA
    [J]. METABOLISM-CLINICAL AND EXPERIMENTAL, 1989, 38 (08): : 89 - 92
  • [3] GLUTAMINE-METABOLISM IN LYMPHOCYTES OF THE RAT
    ARDAWI, MSM
    NEWSHOLME, EA
    [J]. BIOCHEMICAL JOURNAL, 1983, 212 (03) : 835 - 842
  • [4] HEXOSE TRANSPORT AND PHOSPHORYLATION BY CAPILLARIES ISOLATED FROM RAT-BRAIN
    BETZ, AL
    CSEJTEY, J
    GOLDSTEIN, GW
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1979, 236 (01): : C96 - C102
  • [5] IDENTIFICATION OF HYPOXANTHINE TRANSPORT AND XANTHINE-OXIDASE ACTIVITY IN BRAIN CAPILLARIES
    BETZ, AL
    [J]. JOURNAL OF NEUROCHEMISTRY, 1985, 44 (02) : 574 - 579
  • [6] POLARITY OF BLOOD-BRAIN-BARRIER - NEUTRAL AMINO-ACID TRANSPORT INTO ISOLATED BRAIN CAPILLARIES
    BETZ, AL
    GOLDSTEIN, GW
    [J]. SCIENCE, 1978, 202 (4364) : 225 - 227
  • [7] CHOI TB, 1986, J BIOL CHEM, V261, P6536
  • [8] NET AMINO-ACID TRANSPORT BETWEEN PLASMA AND ERYTHROCYTES AND PERFUSED DOG BRAIN
    DREWES, LR
    CONWAY, WP
    GILBOE, DD
    [J]. AMERICAN JOURNAL OF PHYSIOLOGY, 1977, 233 (04): : E320 - E325
  • [9] HARGREAVES KM, 1988, J BIOL CHEM, V263, P19392
  • [10] EVIDENCE FOR CARRIER-MEDIATED TRANSPORT OF GLUTATHIONE ACROSS THE BLOOD-BRAIN-BARRIER IN THE RAT
    KANNAN, R
    KUHLENKAMP, JF
    JEANDIDIER, E
    TRINH, H
    OOKHTENS, M
    KAPLOWITZ, N
    [J]. JOURNAL OF CLINICAL INVESTIGATION, 1990, 85 (06) : 2009 - 2013