NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Effects of hemorrhagic hypotension on tyrosine concentrations in rat spinal cord and plasmaTyrosine is the precursor for catecholamine neurotransmitters. When catecholamine-containing neurons are physiologically active (as sympathoadrenal cells are in hypotension), tyrosine administration increases catecholamine synthesis and release. Since hypotension can alter plasma amino acid composition, the effects of an acute hypotensive insult on tyrosine concentrations in plasma and spinal cord were examined. Rats were cannulated and bled until the systolic blood pressure was 50 mmHg, or were kept normotensive for 1 h. Tyrosine and other large neutral amino acids (LNAA) known to compete with tyrosine for brain uptake were assayed in plasma and spinal cord. The rate at which intra-arterial (H-3)tyrosine disappeared from the plasma was also estimated in hemorrhaged and control rats. In plasma of hemorrhaged animals, both the tyrosine concentration and the tyrosine/LNAA ratio was elevated; moreover, the disappearance of (H-3)tyrosine was slowed. Tyrosine concentrations also increased in spinal cords of hemorrhaged-hypotensive rats when compared to normotensive controls. Changes in plasma amino acid patterns may thus influence spinal cord concentrations of amino acid precursors for neurotransmitters during the stress of hemorrhagic shock.
Document ID
19930074625
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Conlay, L. A.
(Harvard Medical School Boston, MA., United States)
Maher, T. J.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Roberts, C. H.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Wurtman, R. J.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1988
Subject Category
Life Sciences (General)
Report/Patent Number
NAS 1.26:192872
REPT-681
NASA-CR-192872
Accession Number
93N72072
Funding Number(s)
CONTRACT_GRANT: NAG2-210
Distribution Limits
Public
Copyright
Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available