Heinz Fink

Die Wachstumskurve der menschlichen Linse

In a European co-operative research 43 normal human lenses, aged 2.5 to 84.5 years, were analyzed with regard to the development of their wet and dry weights in the course of life, and the relation between the two was investigated. Simple exponentional functions were adapted to the data. It has not been possible to force the curves through the zero point, i.e. the beginning of lens differentiation. Wet and dry weight of the lens seem to increase until death, however, the growth rate decreases considerably with age. The dry weight portion of the lens, being 1/3, is rather constant for the better part of life. However, the individual variability is greater than might be assumed. It has not yet been possible to elucidate whether the lenses of children under the age of 10 generally have a higher water content than those of people above eighty years of age. The growth curves will have to be continually corrected according to the latest data obtained, especially if information on periodical increases of the growth rate during the embryonic phase or at an advanced age will be available. Aus einer europäischen Gemeinschaftsarbeit wurden 43 Augenlinsen von Gesunden zwischen 2,5 und 84,5 Jahren hinsichtlich der zeitlichen Entwicklung ihrer Naß- und Trockengewichte sowie deren Beziehung zueinander analysiert. Einfache Exponentialfunktionen wurden den Daten angepaßt. Hierbei gelang es nicht, die Kurven durch den Nullpunkt zur Zeit des Beginns der embryonalen Entwicklung des Linsenbläschens zu zwingen. Naß- und Trockengewicht der Linse scheinen bis zum Tode zu wachsen, jedoch bringt das Altern eine ganz erhebliche Verlangsamung. Der Trockengewichtsanteil der Linse beträgt während des größten Teils des Lebens ziemlich konstant ein Drittel. Die individuelle Variabilität ist jedoch größer, als man nach dem ersten Eindruck vermutet. Ob Kinder unter 10 Jahren im Mittel einen größeren und Greise über 80 Jahren einen kleineren Wassergehalt haben, kann noch nicht entschieden werden. Die Wachstumskurven werden durch Hinzukommen neuer Daten noch Korrekturen erfahren müssen. Insbesondere wird man über eventuelle Wachstumsschübe während des embryonalen Lebens und im Alter mehr Informationen erhalten.

The quantification of eight enzymes from the ageing rat lens, with respect to sex differences and special reference to aldolase

Eight enzymes, e.g. lactate dehydrogenase, malate dehydrogenase, fructose-diphosphate aldolase, sorbitol dehydrogenase, glucose-6-phosphate dehydrogenase, hexokinase, phosphofructokinase and pyruvate kinase were estimated quantitatively in the rat lens from 37 to 1,211 days of age, by spectrophotometric methods. The activity was expressed as mU/g LWW. All enzymes measured showed declining activities, but LDH, ALD, SDH, G-6-PDH, HK and PFK gave a significant decrease during ageing when plotted semi-logarithmically from 37 to 1,211 days. SDH and G-6-PDH showed a statistically significant difference between the enzymes from the male and the female lenses. The female lens always had a lower activity than the male lens. Of all enzymes the specific activity, expressed as mU/l mg protein, was calculated. This specific activity appeared to be rather constant during ageing, except for ALD. In the female lenses, the specific activity of 7 enzymes was lower than in the male lenses. For ALD the specific activity decreased significantly in the male lens from 5.32 at 37 days to 0.88 at 1,211 days. In the female lens this significant decrease was from 4.97 to 0.81.

Biochemistry of the Ageing Rat Lens

The lens wet weight differed from the age of 136 days: the male lenses were significantly heavier than the female lenses. The dry weight, in percent of the lens wet and dry weight, of the water-soluble proteins decreased and the dry weight of the water-insoluble proteins increased during ageing. At an age of 870 days, when the dry weight curves crossed each other, the lens contains equal amounts of water-soluble and water-insoluble proteins. At the end of the life expectancy, the relation between the water-soluble and water-insoluble moiety was 0.7 for the rat and 3.5 for the bovine lens. The dry weight percent of the water-soluble proteins was lower for the female lens, whereas that of the water-insoluble proteins was higher for the female lens. The male lens, on the contrary, showed a higher percentage of water-soluble and a lower percentage of water-insoluble proteins with increasing age. The ratio R of the dry weight of water-soluble to water-insoluble proteins was, from the age of 429 days, lower for the female lens. During ageing, the proportion of the lens-water was higher for the male lens.

Carbohydrate metabolism of the lens depending on age I. Factor analysis of changes in the content of adenine nucleotides, inorganic phosphate and lactate in bovine lenses

Abstract The content of ATP, ADP, AMP and lactate in 105 bovine lenses of 1.7 to 185 months has been determined. A second preparation of 109 bovine lenses from 1.6 to 167 months was used to measure the content of inorganic phosphate. The concentration of all these substances decreases with increasing age. Extent and temporal course of the decrease vary. Results obtained are calculated by three modifications of factor analysis. It is evident that ATP stands alone in loading a factor, while all other substances and age (with opposite sign) appear as joint representatives of factors. This fact indicates that the ATP content of the lens is not a direct criterion of age but may be a consequence of age-dependent, qualitative changes in carbohydrate-breakdown. This concept is also supported by the behaviour of the ATP/ADP quotient reaching the maximum between 3 1 2 and 6 years of age.

Growth Curve of the Eye Lens of Some Domestic and Test Animals

Research on changes of lens metabolism due to aging postulate the knowledge of animal age. It has been demonstrated by biostatistical and biometrical methods that a growth curve of lens weight once es

Blood Pressure, Blood Flow and Intraocular Pressure

(1) A rise of blood pressure by steps between 80 and 180 mm Hg mean pressure did not cause an increase in intraocular pressure under the conditions which are mentioned above. (2) If, however, slight p

[Carbohydrate metabolism of the lens depending on age. IV. Growth curves of enzyme activities and substrate concentrations of bovine lenses (author's transl)].

The growth curves of the lenses of 1-month old calves to 16-year old bovines were estimated from biochemical determinations of 10 enzymes and 7 substrates. Absolute curves of the contents and relative concentration curves, plottet against the empiric values of determination, are reported and their properties formally classified. An attempt to arrange the results into a general pattern of behaviour and to discuss their biochemical aspects follows. Wachstumskurven aus biochemischen Bestimmungen von 10 Enzymen und 7 Substraten der Linsen von 1 Monat alten Kälbern bis 16 Jahre alten Rindern wurden geschätzt. Absolute Gehaltskurven und relative Konzentrationskurven, gegen die empirischen Bestimmungswerte geplottet, werden mitgeteilt und ihre Eigenschaften formal klassifiziert. Der Versuch einer Einordnung des Ergebnisses in ein allgemeines Verhaltensmuster, sowie dessen Diskussion aus biochemischer Sicht, werden folgen.

Untersuchungen zur Latenzzeit der Galaktosekatarakt von Ratten

X-irradiation influences the latency period of galactose cataracts of rats. Former results indicate that this is true only in case the lens was exposed to the irradiation. By means of either a whole-body irradiation (440 R) or irradiation of the trunk and varying the beginning of the galactose diet (40%), the latency period up to the point when the opacities, beginning in the peripheral part, reach 50% of the lens, has been determined. Findings were monitored by slitlamp photography of the lenses in regredient light. The extent of the opaque area was measured by planimetry. Evaluation of the results was done by three way variance analysis classifying the date of X-irradiation, beginning of galactose diet and manner of irradiation. X-irradiation of the trunk, screening the head and thereby screening the lens, results in a shortened latency period of galactose cataract. The effect is all the more evident, the longer the period between irradiation and the beginning of the diet is. In case of whole-body irradiation, where the lens is also irradiated, two contradictory effects were observed. With rats of 6 and 8 weeks old, the formation of lens opacities was delayed. The effect of X-irradiation was similar to that of aging. The other test groups showed a shortening of the latency period, which may be considered as cumulation cataract. Bei jungen Ratten wurde eine Röntgenbestrahlung von 440 R als Ganzkörper- bzw. Rumpfdosis mit dem Beginn einer 40% igen Galaktosediät variiert und die Latenzzeit bestimmt, in der die peripher einsetzenden Trübungen der Linse 50% der Linsenfläche ausmachen. Die Befunddokumentation erfolgte durch Spaltlampenphotographie der Linsen im regredienten Licht, die Flächenmessung der Trübungszone wurde mittels Planimetrie durchgeführt. Die Versuchsauswertung wurde nach einem Modell einer dreifachen Varianzanalyse durchgeführt, wobei Bestrahlungstermin, Beginn der Galaktosediät und Bestrahlungsart Einflußgrößen waren. Eine Röntgenbestrahlung des Rumpfes unter Abschirmung des Kopfes und damit der Linse bewirkt eine Verkürzung der Latenzzeit der Galaktosekatarakt. Die Wirkung ist um so ausgeprägter, je größer der Zeitraum zwischen Bestrahlung und Diätbeginn ist. Kommt es bei der Ganzkörperbestrahlung zur „Mitbestrahlung“ der Linse, so zeigen sich 2 gegenläufige Effekte. Bei 6 und 8 Wochen alten Ratten wird das Auftreten der Linsentrübung nach Röntgenganzkörperbestrahlung verzögert; die Tiere reagieren so, als wären sie durch die Röntgenapplikation älter geworden. Bei den anderen Versuchsgruppen findet sich eine Latenzzeitverkürzung, die sich im Sinne einer Additionskatarakt interpretieren läßt.

The metabolism of chicken lenses during the first twelve months. An attempt at biological interpretation of a factor analysis.

In 110 experiments 314 lenses from 4 to 361 days old chicken were biochemically studied and enzyme activites were measured. Results were evaluated by regression and factor analyses. The data showed a complex metabolism during the growth period, special parts of which — a growth metabolism, a metabolism for maintenance of physiological conditions, and a metabolism of supperficial fiberlayers — can be described separately. The behaviour of the individual enzymes, depending on age and lens weight, was described and interpreted. 314 Linsen von Hähnchen im Alter von 4 bis 361 Tagen wurden in 110 Ansätzen biochemisch aufgearbeitet und die Aktivitäten von 7 Fermenten gemessen. Die Ergebnisse wurden regressions-und faktorenanalytisch ausgewertet. Es ergab sich, daß die Hähnchenlinse im Wachstumsalter ein vielfältiges Stoffwechselgeschehen aufweist, woraus als besondere Teilkomplexe ein Wachstumsstoffwechsel, ein Erhaltungsstoffwechsel sowie ein Stoffwechsel der oberflächlichen Faserschichten abgetrennt und gesondert beschrieben werden können. Das Verhalten der einzelnen Fermente in Abhängigkeit von Alter und Linsengewicht wurde dargestellt und interpretiert.

Behaviour of Different Enzyme Activities in the Lenses of Chickens during the First Year of Life

In 110 experiments 314 lenses from 4 to 361-day-old chickens were biochemically studied and enzyme activities of Lactate-dehydrogenase (LDH), Malate-dehydrogenase (MDH), NAD-depending-Sorbitol-dehydrogenase (SDH), Fructo-aldolase (ALD), Glucose-6-phosphat-dehydrogenase (G-6-PDH), Glutamate-oxalacetate-transaminase (GOT) and Glutamate-pyruvate-transaminase (GPT) were measured. Results were evaluated by factor analysis. The interpretation of this biostatistical procedure could be assured by additional experiments. Furthermore it is investigated, whether the possibilities of factor analysis and its interpretation permit a relation of the age-dependent sensibility of the lens to X-irradiation. It could be shown, that mostly the metabolism of growth is influenced by ionising radiation, and that as a shift to the metabolism of older lenses. Finally this interpretation is examined by investigations of irradiation influence on the latency period of galactose cataracts in rats.