Closed Colonies Information-3

Animals/Outbred Strains/

Closed Colonies Information-3

*Jcl:Wistar rats often shed reddish tears (chromodacryorrhea). Whereas chromodacryorrhea does not occur in mice, rabbits, or guinea pigs, amphibious animals, such as hippopotamuses, are said to exude red sweat. Rats reportedly exhibit reddish tears after the administration of acetylcholine and 30-40 min of physical restraint with adhesive tape, and the heavier the animal, the earlier the onset (1). These reddish tears are not attributable to erythrocytes, but to porphins derived from the harderian gland. The parasympathetic nerve is thought to mediate onset, since experimentally induced reddish tears are inhibited by atropine (2). Thus, although reddish tears seem to represent a physiologic phenomenon found in rats, the frequency of reddish tears varies among different Jcl rat strains, with the descending order of frequency being Wistar>SD>F344. This, conversely, suggests the high sensitivity of Jcl:Wistar rats.

  1. Harkness JE, Ridgway MD. Chromodacryorrhea in laboratory rats (Rattus norvegicus): etiologic considerations. Lab Anim Sci. 1980;30(5):841-4.
  2. Honma et al. Study on the reddish tears secretory phenomenon in rats. No. 13. Proceedings of lectures at the conference of the Japanese Association for Laboratory Animal Science. p. 47, 1978. (in Japanese)

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