Differential Count of Leucocytes in Vagina of Rat During Oestrous Cycle.

Abstract

The quantitative relations of the types of leucocytes found in the vagina of the rat during the oestrous cycle are not yet clear. Long and Evans 1 state that, during the dioestrous cycle, the leucocytes are chiefly polymorphonuclear. Loewe and Lange 2 found that, though polymorphs are predominant, there are about half as many lymphocytes. No mention is made of the monocyte.

For thirty days I examined the lavages and smears of five apparently normal rats, staining the former with a dilute solution of methylene blue, and the latter with haematoxylin and eosin. Methylene blue could have been used for the smears with much less expenditure of time and energy. The types noted in the first hundred leucocytes encountered were recorded.

A clean pipette is filled with about 1 cc. of physiological salt solution and gently inserted into the vagina. The bulb of the pipette is compressed two or three times, finally released, and the pipette withdrawn. A drop of the lavage is placed on a slide and one drop of a 0.05 % aqueous solution of methylene blue added. A cover slip is applied and the lavage immediately examined. This method was first suggested by Dr. Carl G. Hartman, who found it of great advantage in his studies on the monkey. It is an easy procedure, requiring no elaborate staining technique.

There was no difficulty differentiating monocytes from lymphocytes. A large mononuclear, twice the size of a red blood corpuscle, containing a nucleus of variable crescentic shape, whose cytoplasm is packed with large granules, I considered a monocyte. The lymphocyte generally is smaller than the monocyte; its nucleus is spherical, and the cytoplasm practically clear. The polymorphs, of course, are unique.

A study of this material yielded quite different results from those obtained by Lange. 2