Hj. Harlow et Ej. Braun, GASTRIC NA(-ROTUNDUS()K(+)ATPASE ACTIVITY AND INTESTINAL UREA HYDROLYSIS OF THE COMMON VAMPIRE BAT, DESMODUS), Comparative biochemistry and physiology. Section A: Comparative physiology, 118(3), 1997, pp. 665-669
Citations number
36
Categorie Soggetti
Physiology,Biology
Journal title
Comparative biochemistry and physiology. Section A: Comparative physiology
The blood diet of the vampire bat represents an extraordinarily high r
atio of protein to other nutrients and the highest water consumption p
er body weight of any other mammal. This bat has a unique gastrointest
inal morphology that is characterized by a reduced small intestine, ab
sence of a large intestine and intestinal cecum and the presence of a
water-absorptive gastric fundus. The present study demonstrates that t
he gastric fundus has a greater Na(+)K(+)ATPase activity for active io
n transport compared with Other equally sized mammals; This activity i
s believed to be necessary to establish a gradient favoring water abso
rption across what would otherwise be an osmotic disequilibrium. The a
bsence of a large intestine and intestinal cecum may reflect a reduced
urea hydrolysis by the vampire bat. The present study demonstrated th
at the vampire bat does not hydrolyze urea as does an equally sized no
n-sanguinivorous mammal. These data suggest that the blood diet and th
e relocation of water-absorptive tissue from the lower intestinal trac
t to the stomach is associated with an active ion transport mechanism
in the gastric tissue and a reduced capacity for ureolytic microbes to
hydrolyze urea in the intestine. Both processes are specializations f
or a diet high in protein and water. (C) 1997 Elsevier Science Inc.