PMID- 9491595
OWN - NLM
STAT- MEDLINE
DCOM- 19980326
LR  - 20190921
IS  - 1011-1344 (Print)
IS  - 1011-1344 (Linking)
VI  - 42
IP  - 1
DP  - 1998 Jan
TI  - UVB irradiation alters the activities and kinetic properties of the enzymes of 
      energy metabolism in rat lens during aging.
PG  - 40-6
AB  - Ultraviolet (UV) radiation is one of the major risk factors of cataract (loss of 
      eye-lens transparency). The influence of UVB radiation (300 nm; 100 microW cm-2) 
      on the activity and apparent kinetic constants (Km and Vmax) of rat lens 
      hexokinase (HK;EC 2.7.1.1), phosphofructokinase (PFK; EC 2.7.1.11), isocitrate 
      dehydrogenase (ICDH; EC 1.1.1.41) and malate dehydrogenase (MDH; EC 1.1.1.37) of 
      energy metabolism has been investigated by irradiating the lens homogenate of 
      three- and 12-month-old rats. In the three-month-old group specific activities of 
      HK and PFK are reduced by 56 and 43%, respectively, and there is no change in 
      ICDH and MDH activities after a 24 h exposure. On the other hand, in the 
      12-month-old group the decreases are 72, 71, 24 and 16% for HK, PFK, ICDH and 
      MDH, respectively. UVB irradiation increases the apparent Km of HK and PFK (in 
      both age groups), whereas the Km of ICDH and MDH is not altered. While the 
      decrease in Vmax of these enzymes due to UVB exposure is only marginal in 
      three-month-old rats, it is more pronounced (significant) in 12-month-old rats. A 
      similar decrease in enzyme activities of HK and PFK is also observed upon UVB 
      exposure of the intact rat lens. The photoinduced changes in energy metabolism 
      may in turn have a bearing on lens transparency, particularly at an older age.
FAU - Reddy, G B
AU  - Reddy GB
AD  - Laboratory of Ocular Biochemistry, National Institute of Nutrition, Hyderabad, 
      India. bhanu@mbu.iisc.ernet.in
FAU - Bhat, K S
AU  - Bhat KS
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Switzerland
TA  - J Photochem Photobiol B
JT  - Journal of photochemistry and photobiology. B, Biology
JID - 8804966
RN  - 0 (Proteins)
RN  - EC 1.1.1.37 (Malate Dehydrogenase)
RN  - EC 1.1.1.41 (Isocitrate Dehydrogenase)
RN  - EC 2.7.1.1 (Hexokinase)
RN  - EC 2.7.1.11 (Phosphofructokinase-1)
SB  - IM
MH  - *Aging
MH  - Animals
MH  - Energy Metabolism/radiation effects
MH  - Hexokinase/metabolism/radiation effects
MH  - Isocitrate Dehydrogenase/metabolism/radiation effects
MH  - Kinetics
MH  - Lens, Crystalline/*enzymology/*radiation effects
MH  - Malate Dehydrogenase/metabolism/radiation effects
MH  - Male
MH  - Phosphofructokinase-1/metabolism/radiation effects
MH  - Proteins/metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - *Ultraviolet Rays
EDAT- 1998/03/10 00:00
MHDA- 1998/03/10 00:01
CRDT- 1998/03/10 00:00
PHST- 1998/03/10 00:00 [pubmed]
PHST- 1998/03/10 00:01 [medline]
PHST- 1998/03/10 00:00 [entrez]
AID - S1011134497001140 [pii]
AID - 10.1016/s1011-1344(97)00114-0 [doi]
PST - ppublish
SO  - J Photochem Photobiol B. 1998 Jan;42(1):40-6. doi: 10.1016/s1011-1344(97)00114-0.