Changes in brain phosphorus metabolites during the post‐natal development of the rat.

Publisher Website
Google Scholar
Abstract
Changes in brain phosphorus metabolites during the postnatal development of the rat and in neonatal and adult guinea pigs were studied in vivo using 31P NMR spectroscopy. The brain spectra showed clear differences with age, particularly during the first 3 wk postpartum. The spectra from 4-day-old rats resembled those of newborn human infants. The differences between human and animal brains arise because of an age difference rather than a species difference. The phosphocreatine (PCr) to nucleoside triphosphate (NTP) ratio increased from .apprx. 1.0 in 3-day-old rats to 1.8 in adult animals. An unknown compound in the phosphomonoester (PME) region of the spectra predominated in young animals, but decreased in concentration relative to NTP with age and reached adult values by .apprx. 2 wk postpartum. Neonatal guinea pigs, which are much more developed at birth than the rat, had a significantly greater PCr/NTP ratio than the neonatal rat, but their brain spectra also contained the large PME peak. The intracellular pH of cerebral tissue was estimated to be 7.21 .+-. 0.02 and did not change with age. The changes in the phosphorus compounds in the brain may be of importance in postnatal development and the possible functional significance of these results is discussed.