Inactivity of cerebrospinal fluid in regulation of blood glucose concentration

¹ Harrison Department of Surgical Research and Department of Neurosurgery, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania

Experiments in dogs and rabbits have shown that increasing or decreasing the concentration of glucose in cerebrospinal fluid has no significant effect on the blood glucose concentration. The presence of 2-deoxy-d-glucose or d-ribose in spinal fluid also does not influence blood glucose concentration although these substances have a marked effect when given intravenously. The injection of insulin into the spinal fluid does not affect blood glucose concentration except that if a large amount is injected, then blood glucose concentration decreases as a result of the absorption of insulin from the spinal fluid into the systemic circulation.