Abstract
Cerebral blood flow (CBF) and cerebral plasma volume (CPV) were measured under steady-state hyperglycemic conditions in the hemispheres and brainstem-cerebellum of conscious rats. There groups of hyperglycemic animals each having a different level of plasma glucose concentration, 25,33.3, 44.4 mmol/l, and a normoglycemic control group were studied. CBF was not affected at the hyperglycemic levels of 25 and 33.3 mmol/l. Mean hemispheric and brainstem-cerebellum CBF values appeared lower than in controls at the highest glycemic level althoug the differences were not statistically significant. CPV was found to be unchanged at the hyperglycemic level of 25 mmol/l, while it was found to be increased in the hemispheres of the animals whose plasma glucose concentration had been elevated to 33.3 and 44.4 mmol/l.
The results of the study do not support the claim that hyperglycemia may enhance ischemic brain injury by reducing CBF.
Sommario
Il flusso ematico cerebrale (CBF) e il volume plasmatico cerebrale (CPV) sono stati misurati in corso di iperglicemia costante negli emisferi e nel tronco-cervelletto di ratti. Sono stati studiati tre gruppi di ratti, ciascuno con un diverso livello glicemico, 25, 33.3, 44.4 mml/L e un gruppo normoglicemico di controlo (8–9 ml/L). CBF è risultato immodificato ai livelli iperglicemici di 25 e 33.3 mml/L. Al livello iperglicemico più alto, i valori medi emisferici e del tronco-cervelletto sono risultati più bassi che nel controllo, benché le differenze non fossero statisticamente significative. CPV è stato trovato immodificato alla iperglicemia di 25 mml/L, mentre era aumentato ai livelli di 33.3 e 44.4 mml/L.
I risultati dello studio non sono consistenti coll'ipotesi che l'iperglicemia favorisca il danno ischemico attraverso una riduzione del CBF.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Berger L., Hakim, A.M.:The association of hyperglycemia with cerebral edema in stroke. Stroke 17:865–871, 1986.
Candelise L., Landi G., Orazio E.M., Boccardi E.:Prognostic significance of hyperglycemia in acute stroke. Arch. Neurol. 42:661–663, 1985.
Cremer J.E., Seville M.P.:Regional brain blood flow, blood volume and haematocrit values in the adult rat. J. Cereb. Blood Flow Metabol. 3:254–256, 1983.
De Fronzo R.A., Tobin J.D., Andres R.:Glucose clamp technique: a method for quantifying insulin secretion and resistance. Am. J. Physiol. 237:E214-E223, 1979.
Duckrow R.B., Beard D.C.;Brennam R.W.:Regional cerebral Blood Flow decreases during hyperglycemia. Ann. Neurol. 17:267–272, 1985.
Duckrow R.B., Beard D.C., Brennam R.W.:Regional cerebral blood flow decreases during chronic and acute hyperglycemia. Stroke 18:52–58, 1987.
Geiger A., Magnes J., Taylor R.M., Veralli M.:Effect of blood constituents on uptake of glucose and on metabolic rate of the brain in perfusion experiments. Am. J. Physiol. 177:138–149, 1984.
Gibbs J.M., Wise R.J.S., Leenders K., Jones T.:Evaluation of cerebral perfusion reserve in patients with carotid artery occlusion. Lancet 1: 310–314, 1984.
Gjedde A.:Rapid steady-state analysis of blood-brain glucose transfer in rat. Acta Physiol. Scand. 108:331–339, 1980.
Gjedde A., Crone C.:Blood-brain glucose transfer: repression in chronic hyperglycemia. Science 214:456–457, 1981.
Lucignani G., Namba H., Nehlig A., Porrino L.J., Kennedy C., Sokoloff L.:Hyperinsulinemia selectively increases glucose utilization in the rat hypothalamus. J. Cereb. Blood Flow Metabol. 5 (Suppl. 1):S89, 1985.
Meyers R.E., Yamaguchi S.:Nervous system effects of cardiac arrest in monkeys. Preservation of vision. Arch. Neurol. 34:65–74, 1977.
Nedergaard M., Jakobsen J., Diemer N.H.:Autoradiographic determination of cerebral glucose content, blood flow, and glucose utilization in focal ischemia of the rat brain: influence of the plasma glucose concentration. J. Cereb. Blood Flow Metabol. 8:100–108, 1988.
Orzi F., Lucignani G., Dow-Edwards D., Namba H., Nehlig A., Patlak C.S., Pettigrew K., Schuier F., Sokoloff L.:Local Cerebral Glucose Utilization in controlled graded levels of hyperglycemia in the conscious rat. J. Cereb. Blood Flow Metabol. 8:346–356, 1988.
Pulsinelli W.A., Waldman S., Rawlinson D., Plum F.:Moderate hyperglycemia augments ischemic brain damage: a neuropathologic study in the rat. Neurology 32:1239–1246, 1982.
Pulsinelli W.A:, Levy D.E., Sigsberg B., Scherer P., Plum F.:Damage after ischemic stroke in patients with hyperglycemia with or without established diabetes mellitus. Am. J. Med. 74:540–544, 1989.
Sakurada O., Kennedy C., Jehle J., Brown J.D., Carbin G.L., Sokoloff L.:Measurement of local cerebral blood flow with [14C] iodoantipyrine. Am. J. Physiol. 234:H59-H66, 1978.
Schuier F., Orzi F., Suda S., Kennedy C., Sokoloff L.:The lumped constant (LC) for the [14C]Deoxyglucose method in hyperglycemic rats. J. Cereb. Blood Flow Metabol. 1 (suppl. 1):S63, 1981.
Siemkowicz E., Hansen A.J.:Clinical restitution following cerebral ischemia in hypo-normo-and hyperglycemic rats. Acta Neurol. Scand. 58:1–8, 1978.
Siemkowicz E., Hansen A.J., Gjedde A.:Hyperglycemic ischemia of rat brain: the effect of post-ischemic insulin on metabolic rate. Brain Res. 243:386–390, 1982.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Orzi, F., Schuier, F.J., Rutscheidt, A.P. et al. Cerebral blood flow and plasma volume during hyperglycemia in the conscious rat. Ital J Neuro Sci 11, 459–463 (1990). https://doi.org/10.1007/BF02336565
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02336565