HYPOXANTHINE IN VITREOUS-HUMOR AND CEREBROSPINAL-FLUID - A MARKER OF POSTMORTEM INTERVAL AND PROLONGED (VITAL) HYPOXIA - REMARKS ALSO ON HYPOXANTHINE IN SIDS

Hypoxanthine (Hx) is a degradation product of adenosine. Increased con centrations were reported in cases of hypoxia as well as with prolonge d postmortem interval (PMI). Hx is recommended as an indicator of prol onged (cerebral) hypoxia, for example in victims of sudden infant deat h as well as a new biochemical method for estimation of postmortem tim e [1-3]. The correlation of vitreous Hx values with the time since dea th was reported to be even higher than the vitreous potassium (K+) val ues. The authors' investigations on 92 bodies with known time since de ath gave a completely opposite result: a much higher correlation betwe en vitreous K+ and time since death than vitreous Hx. The possible dis crepancies between these different results will be discussed (disturbi ng of intra-ocular fluid dynamics by repeated sample-taking in the stu dy of Rognum et al. [2]. The results published so far on vitreous Hx v alues in sudden infant death syndrome (SIDS) cases as an indicator for a prolonged cerebral hypoxia are also not convincing. When vitreous c oncentrations of newborn infants or infants of age <6 months are compa red to those of older infants or adults the vitreous diameter must to be taken into consideration (diffusion gradient; Fick'S law of diffusi on). The discrepant results on vitreous Hx as a measure of vital hypox ia and PMI will be discussed. The authors' results on Hx determination s on cerebrospinal fluid in comparison to cerebrospinal spinal (CSF) p otassium will also be briefly addressed.