Is there adaptation of the exocrine pancreas in wild animal? The case of the Roe Deer

Abstract

BackgroundPhysiology of the exocrine pancreas has been well studied in domestic and in laboratory animals as well as in humans. However, it remains quite unknown in wildlife mammals. Roe deer and cattle (including calf) belong to different families but have a common ancestor. This work aimed to evaluate in the Roe deer, the adaptation to diet of the exocrine pancreatic functions and regulations related to animal evolution and domestication.ResultsForty bovine were distributed into 2 groups of animals either fed exclusively with a milk formula (monogastric) or fed a dry feed which allowed for rumen function to develop, they were slaughtered at 150 days of age. The 35 Roe deer were wild animals living in the temperate broadleaf and mixed forests, shot during the hunting season and classified in two groups adult and young. Immediately after death, the pancreas was removed for tissue sample collection and then analyzed. When expressed in relation to body weight, pancreas, pancreatic protein weights and enzyme activities measured were higher in Roe deer than in calf. The 1st original feature is that in Roe deer, the very high content in pancreatic enzymes seems to be related to specific digestive products observed (proline-rich proteins largely secreted in saliva) which bind tannins, reducing their deleterious effects on protein digestion. The high chymotrypsin and elastase II quantities could allow recycling of proline-rich proteins. In contrast, domestication and rearing cattle resulted in simplified diet with well digestible components. The 2nd feature is that in wild animal, both receptor subtypes of the CCK/gastrin family peptides were present in the pancreas as in calf, although CCK-2 receptor subtype was previously identified in higher mammals.ConclusionsBovine species could have lost some digestive capabilities (no ingestion of great amounts of tannin-rich plants, capabilities to secrete high amounts of proline-rich proteins) compared with Roe deer species. CCK and gastrin could play an important role in the regulation of pancreatic secretion in Roe deer as in calf. This work, to the best of our knowledge is the first study which compared the Roe deer adaptation to diet with a domesticated animal largely studied.

The effect of lingonberry leaves and oak cortex addition to sheep diets on pancreatic enzymes activity

“…In the study of Guilloteau et al (2012) performed on young and adult roe deer, higher proteases (chymotrypsin and elastase II) activities than in milk-fed and weaned calves were found. Differences in the pancreatic enzymes activity between those ruminants could result from their digestive system function and feeding behaviour.…”

“…Such proteins form complexes with tannins and comprise the first line of defence against tanninrich plants. Guilloteau et al (2012) showed that proteases activity could be closely related with PRPs secretion in saliva. In the present study insignificant changes in chymotrypsin activity after tannins supplementation were observed.…”

Biochemical parameters of the giant anteater (Myrmecophaga tridactyla Linnaeus, 1758) of the Brazilian Cerrado

“…The enzymes usually measured in a pet clinic when pancreatic damage is suspected are amylase and lipase (Bellier 2010), but because this disease is difficult to diagnose, this evaluation is more complex in wild animals (Guilloteau et al 2012). Although further studies on the physiology of this gland in giant anteaters are needed, it is important to know the reference values of these enzymes, since it is helpful in the diagnosis when there is clinical suspicion of pancreatic alterations.…”