Tags

Type your tag names separated by a space and hit enter

Cerebral carbohydrate and energy metabolism during hypoglycemia in newborn dogs.
Am J Physiol. 1981 Mar; 240(3):R192-9.AJ

Abstract

The metabolic responses of the perinatal brain to hypoglycemia were studied in newborn dogs. Hypoglycemia, induced by the intravenous injection of regular insulin (0.2-0.3 U/g body wt), resulted in final blood glucose concentrations ranging from 0.1 to 1.5 mmol/l; blood lactate levels were little changed from normoglycemic values. Righting, sucking, and nociceptive withdrawal reflexes were progressively lost during the course of hypoglycemia. Slowing of the electroencephalogram was apparent at or below 1.5 mmol/l blood glucose and advanced to paroxysmal discharges and convulsive activity as glucose approached 0.5 mmol/l. In lightly anesthetized, paralyzed, and artificially ventilated puppies, blood glucose concentrations approximating 1.0 mmol/l were associated with a 91% reduction in cerebral glucose; the concentrations of other glycolytic intermediates (glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-diphosphate, pyruvate, lactate) were unchanged from control. Further declines in blood glucose resulted in cerebral glucose levels below 0.1 mmol/kg as well as in partial depletions of all measured glycolytic intermediates including lactate. These changes reflect reduced cerebral glucose consumption and glycolytic flux. Despite the alterations in carbohydrate metabolism, both lactate/pyruvate ratios and high-energy phosphate reserves (phosphocreatine, ATP, ADP) in brain were well preserved even at the extreme of hypoglycemia. The present data, coupled with previous findings of enhanced lactic acid entry into and consumption by newborn dog brain, suggest that this metabolite serves as an important, if not the predominant, substitute fuel for cerebral oxidative metabolism during perinatal hypoglycemia.

Authors

No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

6782896

Citation

Vannucci, R C., et al. "Cerebral Carbohydrate and Energy Metabolism During Hypoglycemia in Newborn Dogs." The American Journal of Physiology, vol. 240, no. 3, 1981, pp. R192-9.
Vannucci RC, Nardis EE, Vannucci SJ, et al. Cerebral carbohydrate and energy metabolism during hypoglycemia in newborn dogs. Am J Physiol. 1981;240(3):R192-9.
Vannucci, R. C., Nardis, E. E., Vannucci, S. J., & Campbell, P. A. (1981). Cerebral carbohydrate and energy metabolism during hypoglycemia in newborn dogs. The American Journal of Physiology, 240(3), R192-9.
Vannucci RC, et al. Cerebral Carbohydrate and Energy Metabolism During Hypoglycemia in Newborn Dogs. Am J Physiol. 1981;240(3):R192-9. PubMed PMID: 6782896.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Cerebral carbohydrate and energy metabolism during hypoglycemia in newborn dogs. AU - Vannucci,R C, AU - Nardis,E E, AU - Vannucci,S J, AU - Campbell,P A, PY - 1981/3/1/pubmed PY - 1981/3/1/medline PY - 1981/3/1/entrez SP - R192 EP - 9 JF - The American journal of physiology JO - Am J Physiol VL - 240 IS - 3 N2 - The metabolic responses of the perinatal brain to hypoglycemia were studied in newborn dogs. Hypoglycemia, induced by the intravenous injection of regular insulin (0.2-0.3 U/g body wt), resulted in final blood glucose concentrations ranging from 0.1 to 1.5 mmol/l; blood lactate levels were little changed from normoglycemic values. Righting, sucking, and nociceptive withdrawal reflexes were progressively lost during the course of hypoglycemia. Slowing of the electroencephalogram was apparent at or below 1.5 mmol/l blood glucose and advanced to paroxysmal discharges and convulsive activity as glucose approached 0.5 mmol/l. In lightly anesthetized, paralyzed, and artificially ventilated puppies, blood glucose concentrations approximating 1.0 mmol/l were associated with a 91% reduction in cerebral glucose; the concentrations of other glycolytic intermediates (glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-diphosphate, pyruvate, lactate) were unchanged from control. Further declines in blood glucose resulted in cerebral glucose levels below 0.1 mmol/kg as well as in partial depletions of all measured glycolytic intermediates including lactate. These changes reflect reduced cerebral glucose consumption and glycolytic flux. Despite the alterations in carbohydrate metabolism, both lactate/pyruvate ratios and high-energy phosphate reserves (phosphocreatine, ATP, ADP) in brain were well preserved even at the extreme of hypoglycemia. The present data, coupled with previous findings of enhanced lactic acid entry into and consumption by newborn dog brain, suggest that this metabolite serves as an important, if not the predominant, substitute fuel for cerebral oxidative metabolism during perinatal hypoglycemia. SN - 0002-9513 UR - https://www.unboundmedicine.com/medline/citation/6782896/Cerebral_carbohydrate_and_energy_metabolism_during_hypoglycemia_in_newborn_dogs_ L2 - https://journals.physiology.org/doi/10.1152/ajpregu.1981.240.3.R192?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -