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001-es BibID:	BIBFORM016928
035-os BibID:	(WoS)000082752600015 (Scopus)0344069638
Első szerző:	Vajda Z.
Cím:	Brain adaptation to water loading in rabbits as assessed by NMR relaxometry / Vajda Z., Berényi E., Bogner P., Repa I., Dóczi T., Sulyok E.
Dátum:	1999
ISSN:	0031-3998
Megjegyzések:	The present study was undertaken to investigate the cerebral adaptationto hypoosmolar stress in adult Pannon white rabbits by applying protonnuclear magnetic resonance relaxometry. Progressive hyponatremia wasinduced by combined administration of hypotonic dextrose in water and8-deamino-arginine vasopressin over a hydration period of 3, 24, and 48h. Each group comprised five animals. After completing the hydrationprotocols, brood was taken to determine plasma osmolality (freezingpoint depression) and sodium concentration (ion-selective electrode)and, at about the same time, T-2-weighted images were made. After thein vivo measurements, the animals were killed and brain tissue sampleswere obtained to measure water content (desiccation method) and T-1 andT-2 relaxation times (proton nuclear magnetic resonance method). Freeand bound water fractions were calculated by using multicomponent fitsof the T-2 relaxation curves. It was shown that brain water content andT-1 relaxation time remained unchanged despite the progressinghyponatremia. By contrast, T-2 relaxation time increased steadily fromthe control value of 100.2 +/- 7.7 ms to attain its maximum of 107.5+/- 8.5 ms (p < 0.05) after 48 h of hydration. Using biexponentialanalysis, fast and slow components of the T-2 relaxation curve could bedistinguished that corresponded to the bound (T-21) and free (T-22)water fractions. In response to hyponatremia, the bound water fractionwas markedly depressed from 6.5 +/- 3.0% to 3.6 +/- 0.9% (3 h, p <0.05) and 3.9 +/- 0.8% (24 h, p < 0.05): then it approached the initialvalue of 5.3 +/- 2.5% by the end of the hydration period of 48 h. It isconcluded that restructuring of brain water is a contributory factor tothe successful adaptation to hypotonic environment.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Pediatric Research. - 46 : 4 (1999), p. 450-454. -
További szerzők:	Berényi Ervin (1964-) (radiológus) Bogner Péter (1963-) (radiológus) Repa Imre (1950-) (radiológus) Dóczi Tamás Sulyok Endre
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