The effects of age on phosphatic metabolites of the human cornea

Cornea. 1995 Jan;14(1):89-94.

Abstract

Phosphatic metabolites from human corneas, pooled into 7 decades ranging from ages < 1 year through 79 years, were quantitated using phosphorus-31 magnetic resonance (31P MR) spectroscopy. Relative concentrations of phosphorus-containing compounds measured included the low-energy metabolites [phosphomonoesters (PME), inorganic orthophosphate (Pi), phosphodiesters (glycerol 3-phosphorylethanolamine and glycerol 3-phosphorylcholine)] and the high-energy metabolites [phosphocreatine (PCr), adenosine triphosphate (ATP), adenosine diphosphate (ADP), nucleosidediphosphosugars and the dinucleotides]. Significant linear changes attributable to age occur in the relative mole percentage decrease of phosphate concentrations of human corneal PME, PCr and ATP, and in the increase of Pi. Age-attributable rates of decrease in PME at -0.162 MPP/YR (mole percent phosphorus per year), PCr at -0.015 MPP/YR and ATP at -0.487 MPP/YR combined, approximate the rate of increase in Pi determined to be +0.729 MPP/YR. Of the indices computed from the human corneal spectral data, the ratios of ATP/Pi and PME/Pi and the tissue energy modulus were all found to decrease significantly with age. These changes in corneal phosphatic metabolites are indicative of an overall decline in high-energy metabolism with age.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging / metabolism*
  • Cell Count
  • Child
  • Child, Preschool
  • Cornea / metabolism*
  • Endothelium, Corneal / cytology
  • Humans
  • Infant
  • Magnetic Resonance Imaging
  • Middle Aged
  • Organophosphates / metabolism*
  • Phosphates / metabolism*
  • Phosphorus Isotopes

Substances

  • Organophosphates
  • Phosphates
  • Phosphorus Isotopes