Letter | Published:

Rheological Properties of Secretions from the Cervix of Pregnant and Non-pregnant Cows

Naturevolume 149pages609610 (1942) | Download Citation



IT has already been observed1 that the flow-curves for bovine cervical secretions tested in an emptying tube viscometer2 show a curvature which exhibits cyclic variations closely related to changes in the cestrous cycle. We have since found that, considering only the lower part (first 33 per cent) of the flow-curve, in which elastic fore-effect preponderates, curves plotting log (L2I2) against log t (which are generally remarkably linear3) show greater slopes for cows known to be pregnant (three months or more) than for non-pregnant animals. (L is the initial length of the column and I the length after time t.) The slopes (Y) vary from a value of about 0.6 near oestrus to about 1. 0 or a little more at some other point in the cycle and reach values sometimes higher than 2. 0 in pregnancy.

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  1. 1

    Scott Blair, G. W., Folley, S. J., Malpress, F. H., and Coppen, F.M.V., Biochem. J., 35, 1039 (1941); NATURE, 147, 453 (1941).

  2. 2

    Scott Blair, G. W., Koli. Z., 78, 19 (1937).

  3. 3

    The linearity of such curves for non-Newtonian honey was commented on in ref. (2).

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  1. National Institute for Research in Dairying, University of Reading

    • , A. T. COWIE
    •  & F. M. V. COPPEN


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