Biochemistry and physiology of gastrointestinal somatostatin

Somatostatin, a tetradecapeptide initially isolated from the ovine hypothalamus, is widely distributed throughout the gastrointestinal tract where it may act as a hormone, local chemical messenger, or neurotransmitter to elicit many physiological actions. Release of somatostatin from D cells in the gut is regulated by mechanisms that are both dependent on and independent of cAMP. In most cases somatostatin acts to inhibit the function of its target cells. It performs this action in part via pertussis-toxin-sensitive inhibitory guanine nucleotide-binding proteins that regulate adenylate cyclase activity. Other mechanisms may involve sites of action distal to intracellular second messenger systems .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44411/1/10620_2005_Article_BF01536041.pd

The value of endoscopy in the diagnosis of lymphoid nodular hyperplasia.

A 16-year-old boy was hospitalized because of abdominal pain, diarrhea, and weight loss. Serum immunoelectrophoresis showed an absence of IgA and diminished levels of IgM and IgG. Radiological examination of the upper gut was suggestive of lymphoid nodular hyperplasia, a diagnosis confirmed by endoscopy and intestinal biopsy. In addition, infestation with Giardia Lamblia was proven by duodenal aspirate at the time of endoscopy