Metabolism of glutamine and glutamate in monkey lenses

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5018631

Jernigan, Jr, H M; Zigler, Jr, J S

In rat lenses, glutamine (GLN), not glutamate (GLU), from the surrounding fluids is the primary source of GLU utilized by several metabolic pathways. To study lenticular amino acid metabolism in a primate, fresh lenses from young (2-3 yr) rhesus monkeys (Macaca mulatta) were incubated at 37/sup 0/C for 3, 6, or 24 hr in balanced salt medium containing 5 mM of amino-labeled /sup 15/N-GLN or /sup 15/N-GLU. The % enrichment of /sup 15/N in several free amino acids was determined by GCMS. GLN entered the monkey lenses more rapidly than GLU, but, in contrast to rat lenses, /sup 15/N-GLN did not more rapidly label other amino acids. The % of /sup 15/N in the (GLN + GLU) pool of the monkey lenses in /sup 15/N-GLN reached 20, 35, and 60% at 3, 6, and 24 hr respectively, compared with 10, 20, and 40% in the lenses in /sup 15/N-GLU. However, in monkey lenses incubated 24 hr with /sup 15/N-GLN, the /sup 15/N in alanine, serine, proline, and (aspartate + asparagine) was only 35, 6, 7, and 30% respectively, compared with 50, 10, 7, and 50% in monkey lenses with /sup 15/N-GLU. Compared with rat lenses, monkey lenses showed slower transport, deamidation, and metabolism of GLN, and less serine, proline, and glycine synthesis. Also, part of the GLU in monkey lenses appeared to be in a slowly transaminating pool. Species differences should be considered when rats are used as a model to study changes in human lenses during aging and cataractogenesis.

• Research Organization: Univ. of Tennessee, Memphis
• OSTI ID: 5018631
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMIDES
AMINO ACIDS
ANIMALS
BIOLOGICAL MODELS
BIOLOGICAL PATHWAYS
CARBOXYLIC ACIDS
GLUTAMINE
ISOTOPE APPLICATIONS
ISOTOPES
LENSES
LIGHT NUCLEI
MAMMALS
METABOLISM
MONKEYS
NITROGEN 15
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PRIMATES
RATS
RODENTS
STABLE ISOTOPES
TRACER TECHNIQUES
VERTEBRATES