Title: | Induced and constitutive responses of digestive enzymes to plant toxins in an herbivorous mammal |
Address: | "Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. kevin.kohl@utah.edu" |
ISSN/ISBN: | 1477-9145 (Electronic) 0022-0949 (Linking) |
Abstract: | "Many plants produce plant secondary compounds (PSCs) that bind and inhibit the digestive enzymes of herbivores, thus limiting digestibility for the herbivore. Herbivorous insects employ several physiological responses to overcome the anti-nutritive effects of PSCs. However, studies in vertebrates have not shown such responses, perhaps stemming from the fact that previously studied vertebrates were not herbivorous. The responses of the digestive system to dietary PSCs in populations of Bryant's woodrat (Neotoma bryanti) that vary in their ecological and evolutionary experience with the PSCs in creosote bush (Larrea tridentata) were compared. Individuals from naive and experienced populations were fed diets with and without added creosote resin. Animals fed diets with creosote resin had higher activities of pancreatic amylase, as well as luminal amylase and chymotrypsin, regardless of prior experience with creosote. The experienced population showed constitutively higher activities of intestinal maltase and sucrase. Additionally, the naive population produced an aminopeptidase-N enzyme that was less inhibited by creosote resin when feeding on the creosote resin diet, whereas the experienced population constitutively expressed this form of aminopeptidase-N. Thus, the digestive system of an herbivorous vertebrate responds significantly to dietary PSCs, which may be important for allowing herbivorous vertebrates to feed on PSC-rich diets" |
Keywords: | "Amylases/metabolism Animals CD13 Antigens/metabolism Chymotrypsin/metabolism Digestive System/*enzymology *Herbivory Larrea/*metabolism Resins, Plant/metabolism Sigmodontinae/*metabolism Sucrase/metabolism alpha-Glucosidases/metabolism;" |
Notes: | "MedlineKohl, Kevin D Dearing, M Denise eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. England 2011/11/26 J Exp Biol. 2011 Dec 15; 214(Pt 24):4133-40. doi: 10.1242/jeb.062356" |