Regulation of cerebral glucose metabolism in normal and polycythemic newborn lambs

Ted S. Rosenkrantz, Anthony F Philipps, Isabella Knox, Edwin L. Zalneraitis, Patricia J. Porte, Peter E. Skrzypczak, John R. Raye

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

In contrast to previous investigations, a recent study of polycythemic lambs suggested that cerebral glucose delivery (concentration × blood flow), not arterial glucose concentration, determined cerebral glucose uptake. In the present study, the independent effects of arterial glucose concentration and delivery on cerebral glucose uptake were examined in two groups of chronically catheterized newborn lambs (control and polycythemic). Arterial glucose concentration was varied by an infusion of insulin. CBF was reduced in one group of lambs (polycythemic) by increasing the hematocrit. At all arterial glucose concentrations, the cerebral glucose delivery of the polycythemic group was 59.6% of the control group. At arterial glucose concentrations of > 1.6 mmol/L, cerebral glucose uptake was constant and similar in both groups. At arterial glucose concentrations of ≤ 1.6 mmol/L, cere-bral glucose uptake was unchanged in the control group, but was significantly decreased in the polycythemic group. In contrast, the cerebral glucose uptake was similar in both groups over a broad range of cerebral glucose delivery values. At cerebral glucose delivery values ≤83 μmol/min/100 g, there was a significant decrease in cerebral glucose uptake in both groups. During periods of low cerebral glucose delivery and uptake, cerebral oxygen uptake fell in the control group but remained unchanged in the polycythemic group. Maintenance of cerebral oxygen uptake in the polycythemic group was associated with an increased extraction and uptake of lactate and β-hydroxybutyrate. We conclude that cerebral glucose delivery, not arterial glucose concentration alone, determines cerebral glucose uptake.

Original languageEnglish (US)
Pages (from-to)856-865
Number of pages10
JournalJournal of Cerebral Blood Flow and Metabolism
Volume12
Issue number5
StatePublished - 1992
Externally publishedYes

    Fingerprint

Keywords

  • Cerebral metabolism
  • Glucose
  • Newborn lamb

ASJC Scopus subject areas

  • Endocrinology
  • Neuroscience(all)
  • Endocrinology, Diabetes and Metabolism

Cite this

Rosenkrantz, T. S., Philipps, A. F., Knox, I., Zalneraitis, E. L., Porte, P. J., Skrzypczak, P. E., & Raye, J. R. (1992). Regulation of cerebral glucose metabolism in normal and polycythemic newborn lambs. Journal of Cerebral Blood Flow and Metabolism, 12(5), 856-865.