Biochemistry of the Lens

Distribution of sodium and potassium within cattle lens

“…These changes were qualitatively similar to the post-mortem penetration of sodium into calf lens shown in Table 8. The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn.…”

“…The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn. If Lebensohn's (1936) data are incorrect, Langham & Davson's (1949) conclusions about the distribution of chloride in lens may need revising, because they used Lebensohn's data on sodium distribution in order to interpret their own analyses of total chloride content.…”

“…The overall sodium and potassium concentrations in old rabbit lens agree with those reported by Heinrichs & Harris (1957) for younger rabbits. DISCUSSION Our values for the total sodium contents of cattle or calf lenses are not in good agreement with Fischer (1933) or Mandel et al (1953). As our values are lower in both cases, it may be that the results of these workers were influenced by contamination with aqueous humour or by post-mortem changes.…”

“…This indicated a higher concentration of sodium in the nucleus than in the cortex. However, it is difficult to reconcile Lebensohn's (1936) high values for sodium in parts of the lens with the much lower value previously reported by Fischer (1933) for the whole lens.…”

Distribution of sodium and potassium within cattle lens

“…These changes were qualitatively similar to the post-mortem penetration of sodium into calf lens shown in Table 8. The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn.…”

“…The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn. If Lebensohn's (1936) data are incorrect, Langham & Davson's (1949) conclusions about the distribution of chloride in lens may need revising, because they used Lebensohn's data on sodium distribution in order to interpret their own analyses of total chloride content.…”

“…The overall sodium and potassium concentrations in old rabbit lens agree with those reported by Heinrichs & Harris (1957) for younger rabbits. DISCUSSION Our values for the total sodium contents of cattle or calf lenses are not in good agreement with Fischer (1933) or Mandel et al (1953). As our values are lower in both cases, it may be that the results of these workers were influenced by contamination with aqueous humour or by post-mortem changes.…”

“…This indicated a higher concentration of sodium in the nucleus than in the cortex. However, it is difficult to reconcile Lebensohn's (1936) high values for sodium in parts of the lens with the much lower value previously reported by Fischer (1933) for the whole lens.…”

The elastic constants of the human lens

“…13 shows the best fitting polynomials for Young's Modulus of LENS ELASTIC CONSTANTS content of the nucleus. Mean values for this quantity (Bellows, 1944) show a slight fall (2 %) from birth to the age of 40, whereas between 40 and 50 yrs of age the fall is much greater (6 %), while Lebensohn (1936) showed that the nucleus is the least hydrated portion of the lens. Since protein in the lens nucleus contains less than 66 % water further dehydration is likely to induce crystallization.…”

Distribution of sodium and potassium within cattle lens

“…These changes were qualitatively similar to the post-mortem penetration of sodium into calf lens shown in Table 8. The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn.…”

“…The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn. If Lebensohn's (1936) data are incorrect, Langham & Davson's (1949) conclusions about the distribution of chloride in lens may need revising, because they used Lebensohn's data on sodium distribution in order to interpret their own analyses of total chloride content.…”

“…The overall sodium and potassium concentrations in old rabbit lens agree with those reported by Heinrichs & Harris (1957) for younger rabbits. DISCUSSION Our values for the total sodium contents of cattle or calf lenses are not in good agreement with Fischer (1933) or Mandel et al (1953). As our values are lower in both cases, it may be that the results of these workers were influenced by contamination with aqueous humour or by post-mortem changes.…”

“…This indicated a higher concentration of sodium in the nucleus than in the cortex. However, it is difficult to reconcile Lebensohn's (1936) high values for sodium in parts of the lens with the much lower value previously reported by Fischer (1933) for the whole lens.…”

The elastic constants of the human lens

“…13 shows the best fitting polynomials for Young's Modulus of LENS ELASTIC CONSTANTS content of the nucleus. Mean values for this quantity (Bellows, 1944) show a slight fall (2 %) from birth to the age of 40, whereas between 40 and 50 yrs of age the fall is much greater (6 %), while Lebensohn (1936) showed that the nucleus is the least hydrated portion of the lens. Since protein in the lens nucleus contains less than 66 % water further dehydration is likely to induce crystallization.…”

Distribution of sodium and potassium within cattle lens

“…These changes were qualitatively similar to the post-mortem penetration of sodium into calf lens shown in Table 8. The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn.…”

“…The data of Lebensohn (1936) remain completely at variance with those of Fischer (1933), Mandel et al (1953 and the present work (Tables 1 and 2) for the total sodium content of cattle lens. Furthermore, the present work (Tables 1-3 and 6) always demonstrates that the direction of the concentration gradient of sodium within the lens is actually opposite to that claimed by Lebensohn. If Lebensohn's (1936) data are incorrect, Langham & Davson's (1949) conclusions about the distribution of chloride in lens may need revising, because they used Lebensohn's data on sodium distribution in order to interpret their own analyses of total chloride content.…”

“…The overall sodium and potassium concentrations in old rabbit lens agree with those reported by Heinrichs & Harris (1957) for younger rabbits. DISCUSSION Our values for the total sodium contents of cattle or calf lenses are not in good agreement with Fischer (1933) or Mandel et al (1953). As our values are lower in both cases, it may be that the results of these workers were influenced by contamination with aqueous humour or by post-mortem changes.…”

“…This indicated a higher concentration of sodium in the nucleus than in the cortex. However, it is difficult to reconcile Lebensohn's (1936) high values for sodium in parts of the lens with the much lower value previously reported by Fischer (1933) for the whole lens.…”

The elastic constants of the human lens

“…13 shows the best fitting polynomials for Young's Modulus of LENS ELASTIC CONSTANTS content of the nucleus. Mean values for this quantity (Bellows, 1944) show a slight fall (2 %) from birth to the age of 40, whereas between 40 and 50 yrs of age the fall is much greater (6 %), while Lebensohn (1936) showed that the nucleus is the least hydrated portion of the lens. Since protein in the lens nucleus contains less than 66 % water further dehydration is likely to induce crystallization.…”