Abstract
Previous studies have shown that severe hypocapnic ventilation [arterial carbon dioxide partial pressure (Paco2) 7–10 mm Hg] in newborn animals results in decreased cerebral blood flow and decreased tissue oxidative metabolism. The present study tests the hypothesis that moderate hypocapnic ventilation (Paco2 20 mm Hg) will result in decreased cerebral oxidative metabolism and nuclear DNA fragmentation in the cerebral cortex of normoxemic newborn piglets. Studies were performed in 10 anesthetized newborn piglets. The animals were ventilated for 1 h to achieve a Paco2 of 20 mm Hg in the hypocapnic (H) group (n = 5) and a Paco2 of 40 mm Hg in the normocapnic, control (C) group (n = 5). Tissue oxidative metabolism, reflecting tissue oxygenation, was documented biochemically by measuring tissue ATP and phosphocreatine (PCr) levels. Cerebral cortical nuclei were purified, nuclear DNA was isolated, and DNA content was determined. DNA samples were separated, stained, and compared with a standard DNA ladder. Tissue PCr levels were significantly lower in the H group than the C group (2.32 ± 0.66 versus 3.73 ± 0.32 μmol/g brain, p < 0.05), but ATP levels were preserved. Unlike C samples, H samples displayed a smear pattern of small molecular weight fragments between 100 and 12,000 bp. The density of DNA fragments was eight times higher in the H group than the C group, and DNA fragmentation varied inversely with levels of PCr (r = 0.93). These data demonstrate that moderate hypocapnia of 1 h duration results in decreased oxidative metabolism that is associated with DNA fragmentation in the cerebral cortex of newborn piglets. We speculate that hypocapnia-induced hypoxia results in increased intranuclear Ca2+ flux, which causes protease and endonuclease activation, DNA fragmentation, and periventricular leukomalacia in newborn infants.
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Abbreviations
- C:
-
control
- CBF:
-
cerebral blood flow
- CP:
-
cerebral palsy
- H:
-
hypocapnic
- NMDA:
-
N-methyl-d-aspartate
- Paco2:
-
partial pressure of carbon dioxide in arterial blood
- Pao2:
-
partial pressure of oxygen in arterial blood
- PCr:
-
phosphocreatine
- PVL:
-
periventricular leukomalacia
References
Volpe J 1998 Neurologic outcome of prematurity. Arch Neurol 55: 297–300
Pidcock FS, Graziani LJ, Stanley C, Mitchell DG, Merton D 1990 Neurosonographic features of periventricular echodensities associated with cerebral palsy in preterm infants. J Peds 116: 417–422
Brian JE 1998 Carbon dioxide and the cerebral circulation. Anesthesiology 88: 1365–1386
Ikonen RS, Janas MO, Koivikko MJ 1992 Hyperbilirubinemia, hypocarbia and periventricular leukomalacia in preterm infants: relationship to cerebral palsy. Acta Paediatr 81: 802–807
Gannon CM, Wiswell TE, Spitzer AR 1998 Volutrauma, Paco2 levels, and neurodevelopmental sequelae following assisted ventilation. Clinics Perinatol 25: 159–175
Graziani LJ, Spitzer AR, Mitchell DG, Merton DA, Stanley C, Robinson N, McKee L 1992 Mechanical ventilation in preterm infants: neurosonographic and developmental studies. Pediatrics 90: 515–522
Fujimoto S, Togari H, Yamaguchi N, Mizutani F, Suzuki S, Sobajima H 1994 Hypocarbia and cystic periventricular leukomalacia in premature infants. Arch Dis Child 71: F107–F110
Okumara A, Hayakawa F, Kato T, Itomi K, Maruyama K, Ishihara N, Kubota T, Suzuki M, Aato Y, Kuno K, Watanabe K 2001 Hypocarbia in preterm infants with periventricular leukomalacia: the relation between hypocarbia and mechanical ventilation. Pediatrics 107: 469–475
Wiswell TE, Graziani LJ, Kornhauser MS, Cullen J, Merton DA, McKee L, Spitzer AR 1996 High-frequency jet ventilation in the early management of respiratory distress syndrome is associated with a greater risk for adverse outcomes. Pediatrics 98: 1035–1043
Lamprecht W 1974 Creatine phosphate. In: Bergmeyer HU, ed. Methods of Enzymatic Analysis. Academic Press, New York, 1777–1781.
Giuffrida AM, Cox D, Mathias AP 1975 RNA polymerase activity in various classes of nuclei from different regions of rat brain during post-natal development. J Neurochem 24: 749–755
Austoker J, Cox D, Mathias AP 1972 Fractionation of nuclei from brain zonal centrifugation and a study of the ribonucleic acid polymerase activity in the various classes of nuclei. Biochem Res 129: 1139–1155
Higuchi Y, Linn S 1995 Purification of all forms of Hela cell mitochondrial DNA and assessment of damage to it caused by hydrogen peroxide treatment of mitochondria or cells. J Biol Chem 270: 7950–7956
Graham EM, Apostolou M, Mishra OP, Delivoria-Papadopoulos M 1996 Modification of the N-methyl-d-aspartate (NMDA) receptor in the brain of newborn piglets following hyperventilation induced ischemia. Neurosci Lett 218: 29–32
Erecinska M, Silver IA 1989 ATP and brain function. J Cereb Blood Flow Metab 9: 2–19
Hansen NB, Nowicki PT, Miller RR, Malone T, Bickers RG, Menke JA 1986 Alterations in cerebral blood flow and oxygen consumption during prolonged hypocarbia. Pediatr Res 20: 147–150
Van Riejn PC, Luyten PR, van der Sprenkel JWB, Kraaier V, van Huffelen AC, Tulleken CAF, den Hollander JA 1989 1H and 31P NMR measurement of cerebral lactate, high-energy phosphate levels, and pH in humans during voluntary hyperventilation: associated EEG, capnographic and Doppler findings. Magn Reson Med 10: 182–193
Carlisson C, Nilsson L, Siesjo B 1974 Cerebral metabolic changes in arterial hypocapnia of short duration. Acta Anaesthesiol Scand 18: 104–113
Akhter W, Zanelli SA, Ballesteros JR, Mishra OP, Delivoria-Papadopoulos M 2000 Effect of graded hypoxia on neuronal intranuclear calcium influx in newborn piglets. Pediatr Res 47: 384A( abstr)
Zanelli SA, Numagami Y, McGowan JE, Mishra OP, Delivoria-Papadopoulos M 1999 NMDA receptor mediated calcium influx on cerebral cortical synaptosomes of the hypoxic guinea pig fetus. Neurochem Res 24: 437–449
Halliwel B 1999 Antioxidant defense mechanisms: from the beginning to the end (of the beginning). Free Radic Res 31: 261–272
Mishra OP, Delivoria-Papadopoulos M 1999 Cellular mechanisms of hypoxic injury in the developing brain. Brain Res Bull 48: 233–238
Maulik D, Qayyum I, Powell SR, Karantza M, Mishra OP, Delivoria-Papadopoulos M 2001 Post-hypoxic magnesium decreases nuclear oxidative damage in the fetal guinea pig brain. Brain Res 890: 130–136
Numagami Y, Zubrow AB, Mishra OP, Delivoria-Papadopoulos M 1997 Lipid free radical generation and brain cell membrane alteration following nitric oxide synthase inhibition during cerebral hypoxia in the newborn piglet. J Neurochem 69: 1542–1547
Ikeda J, Terakawa S, Murota S, Morita I, Hirakawa K 1996 Nuclear disintegration as a leading step of glutamate excitotoxicity in brain neurons. J Neurosci Res 43: 613–622
Nath R, Scott M, Nadimpalli R, Gupta R, Wang KK 2000 Activation of apoptosis-linked caspase(s) in NMDA-injured brains in neonatal rats. Neurochem Int 36: 119–126
Gerasimenko OV, Gerasimenko JV, Tepikin AV, Petersen OH 1996 Calcium transport pathways in the nucleus. Eur J Physiol 432: 1–6
Humbert J-P, Matter N, Artault J-C, Koppler P, Malviya AN 1996 Inositol 1,4,5-triphosphate receptor is located to the inner nuclear membrane vindicating regulation of nuclear calcium signaling by inositol 1,4,5-triphosphate. J Biol Chem 271: 478–485
Tominaga T, Kure S, Narisawa K, Yoshimoto T 1993 Endonuclease activation following focal ischemic injury in the rat brain. Brain Res 608: 21–26
Collins RJ, Harmon BV, Gibe GC, Kerr JFR 1992 Internucleosomal DNA cleavage should not be the sole criterion for identifying apoptosis. Int J Radiat Biol 61: 451–453
Compton MM 1991 Development of an apoptosis endonuclease assay. DNA Cell Biol 10: 133–141
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Supported by NIH HD-20337, NIH HD-38079 and NIH HL-07027.
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Fritz, K., Ashraf, Q., Mishra, O. et al. Effect of Moderate Hypocapnic Ventilation on Nuclear DNA Fragmentation and Energy Metabolism in the Cerebral Cortex of Newborn Piglets. Pediatr Res 50, 586–589 (2001). https://doi.org/10.1203/00006450-200111000-00009
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DOI: https://doi.org/10.1203/00006450-200111000-00009
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