AUTORADIOGRAPHY &PHYSIOLOGY OF GASTROINTESTINE PEPTIDES

Project: Research project

Project Details

Description

The research plan consists of two major projects. The first is to
define the physiologic responses of the feline ileocecal sphincter
(ICS) to feeding and to local stimuli such as distension, and to
determine the contribution of various components of the anatomic
ICS to these physiologic responses. These studies will contribute
to an understanding of the integrative role, if any, of the ICS to
the differing functions of the ileum and colon. The project
consists of using three methods, an in vivo method and two in
vitro methods to examine these problems. Discrepancy exists in
the literature between studies performed in vivo and in vitro. The
proposed studies will be directed to determine the reason for such
discrepancies. The pathways mediating ICS relaxation to
proximal distension, and contraction to distal distension will be
defined. The effect of many peptides which are either released
after meals or have been described to be present in the ICS, and
their sites of action will be examined in vivo and in vitro. The
integrative function of the ileum, ICS and colon in this area will
be examined using myotomy techniques in vivo and in vitro. In
addition, the possible role of vasoactive intestinal peptide as the
neurotransmitter mediating relaxation at the ICS will be studied.
The second major project of this research plan is the development
of the technique of autoradiography of peptide receptors in the
gastrointestinal tract. The methodology for autoradiography of
opiate-, substance P-, bombesin-, as well as cholinergic and
adrenergic receptors will be determined. This technique has not
previously been applied to the gastrointestinal tract with respect
to neuropeptides and neurotransmitters relevant to
gastrointestinal motility. Quantitative autoradiography will allow
the comparison of receptor sites and densities in different areas
of the gastrointestinal tract and allow a comparison of the
receptor population with physiologic responses in vivo and in
vitro.
StatusFinished
Effective start/end date9/1/878/31/91

Funding

  • National Institutes of Health
  • National Institutes of Health