Type of Document	Master's Thesis
Author	Pan, YuanXiang
URN	etd-3856112379652351
Title	POLY(A)+ RNA FROM SHEEP OMASAL EPITHELIUM INDUCES EXPRESSION OF A PEPTIDE TRANSPORT PROTEIN(S) IN XENOPUS LAEVIS OOCYTES
Degree	Master of Science
Department	Animal and Poultry Sciences
Advisory Committee	Advisor Name Title E. A. Wong Committee Co-Chair K. E. Webb Jr. Committee Co-Chair J. H. Herbein none J. R. Bloomquist none
Keywords	sheep omasum peptide transport electrophysiology
Date of Defense	1996-08-09
Availability	unrestricted
Abstract In order to verify the research from this laboratory that sheep omasal epithelium contains mRNA encoding for a peptide transporter (s) and to determine di- to octapeptide transport capability, poly(A)+ RNA isolated from sheep omasal epithelium was injected into Xenopus laevis oocytes. Poly(A)+ RNA was functionally expressed in Xenopus oocytes 4 to 7 d post-injection. Peptide (5 di-, 10 tri-, 6 tetra-, 2 penta-, 1 hepta-, 1 septa-, 1 octapeptide) transport capability was measured by impaling oocytes with a microelectrode to monitor membrane potential (Vm). Oocytes were maintained in pH 5.5 buffer. Peptide transport was identified as being expressed when, in the presence of a buffered peptide substrate (1 mM), the oocyte membrane showed persistent depolarization (a more positive Vm). In the absence of peptide transport, the membrane became depolarized with the addition of buffered substrate, but rapidly repolarized to the resting potential. Peptide transport was expressed for some di-, tri-, and tetrapeptides. Measured depolarization ranged from 9.6 mV to 42.1 mV. Larger peptides were not transported by the oocytes. When transport expression was measured with the substrates in a pH 7.5 buffer, no transport occurred indicating that transport was dependent on a proton gradient. The data indicate that sheep omasal epithelium contains mRNA that code for a protein(s) capable of proton-dependent di-, tri-, and tetrapeptide transport. This provides further evidence that absorption of peptides from the ruminant stomach is possible.
Files	Filename       Size       Approximate Download Time (Hours:Minutes:Seconds)     28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access    etd.pdf 167.67 Kb 00:00:46 00:00:23 00:00:20 00:00:10 < 00:00:01   pan_thesis.pdf 167.67 Kb 00:00:46 00:00:23 00:00:20 00:00:10 < 00:00:01

If you have questions or technical problems, please Contact DLA.