The effect of diet on the plasma-phosphatase of sheep

Abstract

RECENT work on the role of phosphatase has made it clear that the enzyme is closely concerned in the metabolism of calcium and phosphorus and in bone formation. Thus, it has been shown that an increased plasma-phosphatase content accompanies certain bone diseases in human beings [Kay, 1930], that a rise in value also occurs during the healing of fractures [McKeown and Ostergren, 1931], and that, during the healing of rickets in children, the phosphatase values are still abnormally high even after the serum-Ca and blood-inorganic P have returned to normal [Smith and Maizels, 1932]. Bodansky and Jaffe [1931] observed that certain dietary deficiencies were accompanied by changes in the serum-phosphatase of rats.In view of the marked changes which have been found in the serum-Ca levels of sheep suffering from experimentally produced "bent-leg" [Auchinachie and Fraser, 1932], it was considered desirable to determine whether the plasmaphosphatase of sheep fed on the same or similar diets would be affected in any way.EXPERIMENTAL. Blood samples were drawn at monthly intervals, and the plasma-phosphatase, serum-Ca, and blood-inorganic P values were determined. Plasma-phosphatase was estimated by the method of Kay [1930], serum-Ca by Tisdall's modification of the Kramer-Tisdall technique, and inorganic P by Havard and Reay's modification of Briggs's adaptation of the Bell-Doisy method. The sheep were also weighed at monthly intervals.Exp.

Observations on the serum phosphatase of cattle and sheep

“…Comparing the serum phosphatase levels in pregnant and non-pregnant cows in Table 8, it is noted that there is a higher proportion of low values among the non-pregnant cows and that the scatter of values is wider among the pregnant cows, suggesting at first sight a tendency towards higher serum phosphatase values in pregnancy. Our data, therefore, are more in line with those of Vermehren [1939] on women than with .those of Wilson & Hart [1932] and Auchinachie & Emslie [1933] on cattle and sheep.. It must, however, be admitted that our data are not sufficiently extensive to preclude the possibility of a decrease in serum phosphatase in late pregnancy such as was suggested by the results of Auchinachie & Emslie [1933] on six cows sampled during the fifth and eighth months of pregnancy.…”

“…Our data, therefore, are more in line with those of Vermehren [1939] on women than with .those of Wilson & Hart [1932] and Auchinachie & Emslie [1933] on cattle and sheep.. It must, however, be admitted that our data are not sufficiently extensive to preclude the possibility of a decrease in serum phosphatase in late pregnancy such as was suggested by the results of Auchinachie & Emslie [1933] on six cows sampled during the fifth and eighth months of pregnancy. The data given in the last three colu'mns of Table 8 do not suggest the existence of any pronounced relation between stage of pregnancy and.…”

“…Serum phosphatase is raised above normal in certain generalized bone disorders in man, such as rickets-infantile, renal and adult), generalized osteitis fibrosa, osteitis deformans and obstructive jaundice [see Folley & Kay, 1936, 1], and it has also been claimed that it is raised in certain other diseases such as tuberculosis and carcinoma, but the evidence here is less conclusive. Since serum phosphatase values have proved of diagnostic value in disordered Ca and P metabolism in man it was hoped that the same might hold in farm animals, as was suggested, on the basis of a limited number of observations on sheep, by Auchinachie & Emslie [1933].…”

The relation between rates of growth and rickets in sheep on diets deficient in vitamin D.

“…In contrast to this the behaviour of the skeleton, in response to deficiencies or experimental interference with organic functions, is much more constant from species to species, and attention is thus strongly directed towards species differences in the structure, mechanics and functions of the gastrointestinal tract and to factors influencing absorption. In spite of the differences between sheep and non-ruminants no study, along classical lines of nutritional research, of the Ca, P and vitamin D interrelations of this species has been reported except those of Auchinachie & Fraser (1932) and Auchinachie & Emslie (1933). In these investigations the procedures used, although well suited to the problems under study, did not allow an extensive interpretation of the results to answer conclusively certain fundamental questions of relations between Ca, P and vitamin D that have already been clarified for other species.…”

Discussion on the Assessment of the State of Nutrition

“…I know of only one blood constituent the level of which gives pre-symptomatic indication of disordered metabolism, that is the phosphatase content. It has been shown that abnormally high phosphatase levels, even without clinical evidence, are an indication of impending breakdown in metabolism of calcium and phosphorus [11]. The amounts of blood required for this test are, unfortunately, too large for the test to be feasible in clinics.…”