LIFE-SPAN SHORTENING FROM VARIOUS TISSUE INSULTS 



2G9 



Thereafter, as the controls age, kidney function declines sharply until it 

 approaches experimental values. 



.1 1.120 

 ^ 1.1 10 

 S. 1. 100 

 I 1.090 

 ^ 1.080 

 ^ 1.070 

 ^ 1.060 



"1 — 1 \ 1 I i I I I I r 



Kidney function 

 after 24 hr water fast 



HgClg 

 stopped 



T — \ 1 1 r 



V) 



1.050 

 1.040 



40mg/kg HgClg 



20mg/kg HgClg 



Control 



I 1 I I I I I L 



I I I I I 



60 100 140 180 220 260 300 340 380 420 460 



Age (days) 



Fig. 2. Variation of urine specific gravity with age for normal and mercury-poisoned mice. 



Figure 3 shows survival curves to date and experimental groups show 

 mortality rates advanced over the controls. 



Figure 4 shows the weights of experimental animals and controls. 



0) 



100 

 90 

 80 

 70 

 60 

 50 

 40 

 30 

 20 

 10 



60 



"r~i — r 



-~<^---^^^^^;^^^.. 



1 1 r 



1 I r 



HgClg 

 stopped 



40mg/kg 



20mg/kg 



Control 



I 1 I 1 1 I 



I I I I 1 1 



100 140 180 



220 260 300 340 380 420 460 

 Age (days) 



Fig. 3. Svu-vival curves for normal and mercury-poisoned mice. 



DISCUSSION 



It is thus apparent that if damage is created in an organ which has only 

 limited regenerative power, this organ can act as a "weak link" and eventually 

 lead to organ failure and death. Thus tissue insults can be a factor in the ageing 

 process. However, the fact that function was virtually normal for some time 



