The Paneth cell population of the small intestine of the rat-effects of fasting and zinc deficiency on total count and on dithizone-reactive count.

The distribution of Paneth cells in the rat small intestine was found to be approximately one per crypt in the duodenum, two to three per crypt in the jejunum and four to six per crypt in the ileum. The ileum has more Paneth cells containing dithizone-reactive zinc than the duodenum and jejunum. Zinc deficiency had no significant effect on the total Paneth cell count but no dithizone-reactive Paneth cells were found in any area of the small intestine examined in zinc-deficient animals. Fasting for 3 days had no significant effect on the Paneth cell count but after a 4-day fast there was a significant rise in the total Paneth cell count accompanied by a fall in the percentage of Paneth cells containing dithizone-reactive zinc in all areas examined.