Abstract
Contrary to what is found in most vertebrates, the brains of certain turtle species maintain ATP levels and ion homeostasis and survive prolonged anoxia. The hypothesis tested here is that the release of adenosine and its binding to A1 receptors are essential for this anoxic tolerance. Studies were conducted in the isolated turtle cerebellum, which did release adenosine to the extracellular space during anoxia. When adenosine receptor antagonists [theophylline, 8-cyclopentyltheophylline (CPT), or 8-cyclopentyl-l,3-dipropylxanthine (DPCPX)] were added to the superfusate under control conditions, they had no effect on extracellular potassium ion activity ([K + ]0. During anoxia, however, these antagonists provoked maximal efflux of K + (anoxic depolarization). Anoxic depolarization occurred earlier during anoxia with theophylline (a nonspecific adenosine receptor antagonist) than with CPT or DPCPX, which specifically block A1 receptors. Therefore, adenosine release and effects mediated by A1 receptors are essential to anoxia tolerance in turtle brain.
| Original language | English |
|---|---|
| Pages (from-to) | 728-732 |
| Number of pages | 5 |
| Journal | Journal of Cerebral Blood Flow and Metabolism |
| Volume | 13 |
| Issue number | 4 |
| State | Published - Dec 1 1993 |
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Keywords
- A receptors
- Adenosine
- Anoxia
- Cerebellum
- Sodium channels
- Turtle
ASJC Scopus subject areas
- Endocrinology
- Endocrinology, Diabetes and Metabolism
- Neuroscience(all)
Cite this
Adenosine, a "retaliatory" metabolite, promotes anoxia tolerance in turtle brain. / Perez-Pinzon, Miguel; Lutz, Peter L.; Sick, Thomas; Rosenthal, Myron.
In: Journal of Cerebral Blood Flow and Metabolism, Vol. 13, No. 4, 01.12.1993, p. 728-732.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Adenosine, a "retaliatory" metabolite, promotes anoxia tolerance in turtle brain
AU - Perez-Pinzon, Miguel
AU - Lutz, Peter L.
AU - Sick, Thomas
AU - Rosenthal, Myron
PY - 1993/12/1
Y1 - 1993/12/1
N2 - Contrary to what is found in most vertebrates, the brains of certain turtle species maintain ATP levels and ion homeostasis and survive prolonged anoxia. The hypothesis tested here is that the release of adenosine and its binding to A1 receptors are essential for this anoxic tolerance. Studies were conducted in the isolated turtle cerebellum, which did release adenosine to the extracellular space during anoxia. When adenosine receptor antagonists [theophylline, 8-cyclopentyltheophylline (CPT), or 8-cyclopentyl-l,3-dipropylxanthine (DPCPX)] were added to the superfusate under control conditions, they had no effect on extracellular potassium ion activity ([K + ]0. During anoxia, however, these antagonists provoked maximal efflux of K + (anoxic depolarization). Anoxic depolarization occurred earlier during anoxia with theophylline (a nonspecific adenosine receptor antagonist) than with CPT or DPCPX, which specifically block A1 receptors. Therefore, adenosine release and effects mediated by A1 receptors are essential to anoxia tolerance in turtle brain.
AB - Contrary to what is found in most vertebrates, the brains of certain turtle species maintain ATP levels and ion homeostasis and survive prolonged anoxia. The hypothesis tested here is that the release of adenosine and its binding to A1 receptors are essential for this anoxic tolerance. Studies were conducted in the isolated turtle cerebellum, which did release adenosine to the extracellular space during anoxia. When adenosine receptor antagonists [theophylline, 8-cyclopentyltheophylline (CPT), or 8-cyclopentyl-l,3-dipropylxanthine (DPCPX)] were added to the superfusate under control conditions, they had no effect on extracellular potassium ion activity ([K + ]0. During anoxia, however, these antagonists provoked maximal efflux of K + (anoxic depolarization). Anoxic depolarization occurred earlier during anoxia with theophylline (a nonspecific adenosine receptor antagonist) than with CPT or DPCPX, which specifically block A1 receptors. Therefore, adenosine release and effects mediated by A1 receptors are essential to anoxia tolerance in turtle brain.
KW - A receptors
KW - Adenosine
KW - Anoxia
KW - Cerebellum
KW - Sodium channels
KW - Turtle
UR - http://www.scopus.com/inward/record.url?scp=0027316181&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027316181&partnerID=8YFLogxK
M3 - Article
C2 - 8314926
AN - SCOPUS:0027316181
VL - 13
SP - 728
EP - 732
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
SN - 0271-678X
IS - 4
ER -