DH44 neurons: gut-brain amino acid sensors

To assess the role of brain amino acid neurotransmitters in the breath hold of diving animals, concentrations of free amino acids present in the brains of turtles immediately after 2 h of apneic diving (at 20 degrees C) were measured. Additionally, the same measurements were performed on four other groups of animals subjected to 2 h of hypercapnia (8% CO2 in air), anoxia (N2 breathing), anoxia plus hypercapnia (8% CO2–92% N2), or air breathing (control). Significant changes in the concentrations of the inhibitory amino acid neurotransmitters known to affect respiration [gamma-aminobutyric acid (GABA) and taurine] were seen. GABA increased significantly in those animals subjected to anoxia, whereas taurine decreased significantly in the diving animals and increased significantly in those subjected to anoxia plus hypercapnia. These results suggest that the attenuated central ventilatory drive during diving in these animals may be related to alterations in brain concentrations of GABA and taurine.

Download Full-text

O.67 Alterations in extracellular brain amino acid concentrations in PC-shunted rats

Clinical Nutrition ◽

10.1016/s0261-5614(83)80069-7 ◽

1983 ◽

Vol 2 ◽

pp. 36

Author(s):

L.S. Eriksson ◽

A. Delin ◽

U. Tossman ◽

U. Ungerstedt

Keyword(s):

Amino Acid ◽

Amino Acid Concentrations ◽

Brain Amino Acid

Download Full-text

Dissociation between plasma and brain amino acid profiles and short-term food intake in the rat

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1994.266.5.r1675 ◽

1994 ◽

Vol 266 (5) ◽

pp. R1675-R1686 ◽

Cited By ~ 3

Author(s):

G. H. Anderson ◽

E. T. Li ◽

S. P. Anthony ◽

L. T. Ng ◽

R. Bialik

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Food Intake ◽

Amino Acid Mixture ◽

Acid Mixture ◽

Short Term ◽

Egg Albumin ◽

Amino Acid Profiles ◽

Total Mixture ◽

Brain Amino Acid

The relationship between plasma and brain amino acids and short-term food intake after administration of albumin, or its constituent amino acids, was examined. Rats given protein (0.85 g chicken egg albumin) or an amino acid mixture patterned after egg albumin reduced their food intake during 1 h of feeding beginning 30 min after gavage. Similarly, when given separately, the essential (EAA) and nonessential amino acid (NEAA) fractions of egg albumin caused comparable decreases in food intake. As the dose increased from 0.5 to 1.5 g the duration of anorexia prolonged to 12 h. Little change occurred in plasma amino acids at 30 and 60 min after albumin at 0.85 g, although many increased by 25-50% at 60 min after 1.5 g. Marked changes in plasma occurred after gavage with the total mixture of constituent free amino acids and after either EAA or NEAA fractions. Brain amino acid concentrations were little affected by albumin and did not show consistent changes after the amino acid treatments. Thus the reductions in food intake after ingestion of albumin or of its constituent amino acids were not predicted from the resulting changes in either plasma or brain concentrations of amino acids.

Download Full-text