PIGMENT IN THE HARDERIAN GLANDS OF MICE EXPOSED TO A HOT ENVIRONMENT

¹ The Medical Research Council Unit for Climate and Working Efficiency, Department of Human Anatomy, University Museum, Oxford

1. Examination of the Harderian glands of 21-week-old inbred and hybrid strains of mice reveals that the glands may contain at least two different pigments.

2. The colour of the gland appears to be an inherited character due to the presence of a "melanin-like" pigment.

3. Different strains of mice also possess varying amounts of porphyrin pigment which fluoresces under ultra-violet light.

4. An increase in the porphyrin content of the Harderian glands can be produced by exposure to an environment of 91° F. dry bulb and 85° F. wet bulb.

5. A condition similar to chromodacryorrha in the rat can be induced in heat-exposed mice by intraperitoneal injections of acetylcholine.

Note:

I wish to record my thanks to Mr. G. A. Harrison for allowing me to conduct these experiments on the inbred stock of mice, to Dr. K. Hellmann for his help with the inception of the work, and to Dr. J. S. Weiner for much helpful advice and criticism. I am also indebted to Mr. C. W. Graham and Mr. J. O. C. Willson for constant technical assistance.