Ultraviolet radiation effects on rat lens lactate dehydrogenase. An estimation of
UVR penetration depth into the eye.
Stefan Löfgren, MD (a, b), Per G. Söderberg, MD, PhD (a), Ralph
Michael, MMedSci, Dipl. Ing. (a)
- (a) St. Erik´s Eye Hospital, Research Department, S-112 82
- (b) Department of Medical Biochemistry and Biophysics,
- Karolinska Institutet, Stockholm,
(Poster presented at the 1st
Internet Conference on Photochemistry and Photobiology, 1997)
Since a long time it has been known that experimental exposure to ultraviolet radiation
(UVR) damages the lens and induces cataract. Epidemiological studies show a correlation
between exposure to solar UVR-B (280-315 nm) and increased incidence of cataract (reviewed
by Bergmanson & Söderberg 1995). One hypothesis for the experimental UVR-induced
cataractogenesis is that shortage of energy inhibits the ion-pumps (Söderberg 1990). UVR
decreases the lens glycolytic activity in vivo (Löfgren & Söderberg 1995) and
decreases lactate dehydrogenase (LDH) activity in vitro (Chen et al. 1989).
To further elucidate if the UVR inhibition of glycolysis in the lens in vivo
(Löfgren & Söderberg 1995) could be caused by LDH inhibition, an optimised
histochemical procedure for the determination of LDH in lens sections was employed
(Löfgren & Söderberg, 1997).
The histochemical technique was also applied to obtain information on the penetration
of UVR-300 nm into the lens. Transmittance studies on different species have shown that
only a minor part of UVR-300 nm falling on the cornea reaches the anterior surface of the
lens and of that, in practice all radiation is attenuated within the lens (Bachem 1956,
Barker 1979, Boettner & Wolter 1962, Gorgels et al. 1992, Maher 1978).