Distribution of tissue eosinophil granulocytes in cow and pig organs.

Tissue eosinophils were systematically determined from 36 organs or tissues of three cows and three pigs. The number of eosinophils ranged from 0 to 1,500 per mm2. Their densities were highest in the intestinal region, especially the small intestine. Moderate numbers (50–200 per mm2) were noted in the stomach, spleen, lymph nodes, thymus, dermis, and conjunctiva. No eosinophils were seen in 12 tissues. The quantitative presence of tissue eosinophils in the different organs suggests that they are part of the local, cellular defence mechanism of the organism.