Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085383 (hypocapnia)
 1,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We determined regional cerebral blood flow (rCBF) using [125I]HIPDm [N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamin e] and [125I]iodoantipyrine autoradiography under control and pathologic conditions (hypercapnia [acidosis], hypocapnia [alkalosis], and disrupted blood-brain barrier) conditions in 35 rats. In control rats, HIPDm rCBF (indicator fractionation method, n = 5) was lower than the corresponding IAP rCBF (diffusible indicator method, n = 4), most notably in the infratentorial regions and subcortical nuclei. In hypercapnia, rCBF increased by 100% and 37% in the HIPDm (n = 5) and IAP (n = 5) groups, respectively. In hypocapnia, IAP rCBF (n = 4) decreased 34% but HIPDm rCBF (n = 4) did not change. Following disruption of the blood-brain barrier by intracarotid infusion of mannitol in eight rats, both radiotracers (HIPDm n = 4, IAP n = 4) showed decreased rCBF to regions of disruption as defined by trypan blue extravasation. Our work indicates that modeling HIPDm uptake to quantify rCBF using the indicator fractionation method will underestimate blood flow and that HIPDm kinetics are influenced by compartmental pH dynamics that will limit the accuracy of this method in quantifying rCBF in pathologic conditions.
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PMID:Comparison of [125I]HIPDm and [125I]iodoantipyrine in quantifying regional cerebral blood flow in rats. 318 25

Spinal cord blood flow (SCBF) and its response to alterations in blood gases and to systemic hypotension, haemodilution and barbiturate anaesthesia were measured in 47 rats at the level of Th 7-8 by quantitative autoradiography with [14C]iodoantipyrine ([14C]IAP) as tracer. During normocapnia and normoxia the mean SCBF values in the grey and white matter were 94 +/- 21 and 17 +/- 3 ml min-1 100 g-1, respectively. SCBF was highly dependent on PaCO2. Thus in hypercapnic animals (PaCO2 greater than 9 kPa) SCBF was increased in grey and white matter to 228 +/- 22 and 54 +/- 7 ml min-1 100 g-1, while during hypocapnia (PaCO2 less than 3.9 kPa) it was decreased to 64 +/- 14 and 11 +/- 2 ml min-1 100 g-1, respectively. Mean arterial blood pressure (MABP) was reduced by withdrawal of blood to 80 +/- 8 mmHg in a light hypotension group and to 53 +/- 11 mmHg in a severe hypotension group, compared with 126 +/- 13 mmHg in a control group. There was no significant difference in SCBF between the control group and the hypotension groups, suggesting that autoregulation is maintained down to an MABP of at least 50 mmHg. Normovolaemic haemodilution, with a reduction of the haematocrit from 50 +/- 2 to 33 +/- 3, increased SCBF to 113 +/- 9 ml min-1 100 g-1 in grey matter and to 21 +/- 12 ml min-1 100 g-1 in white matter.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Regulation of spinal cord blood flow in the rat as measured by quantitative autoradiography. 322 34