Association analysis of the proneurotensin gene and bipolar disorder

Gastric Activity and Gut Peptides in Patients With Functional Dyspepsia: Postprandial Distress Syndrome Versus Epigastric Pain Syndrome

GOALS

The goals of the study were to investigate in both postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) the gastric electrical activity and the gastric emptying (GE) time together with the circulating concentrations of motilin, somatostatin, corticotrophin-releasing factor, and neurotensin, and to establish whether the genetic variability in the neurotensin system genes differs between these 2 categories of functional dyspepsia (FD).

BACKGROUND

The current FD classification is based on symptoms and it has been proven not to be completely satisfying because of a high degree of symptom overlap between subgroups.

STUDY

Gastric electrical activity was evaluated by cutaneous electrogastrography: the GE time by C-octanoic acid breast test. Circulating concentrations of gut peptides were measured by a radioimmunoassay. NTS 479 A/G and NTSR1 rs6090453 SNPs were evaluated by PCR and endonuclease digestion.

RESULTS

Fifty-four FD patients (50 female/4 male) were studied. Using a symptom questionnaire, 42 patients were classified as PDS and 12 as EPS, although an overlap between the symptom profiles of the 2 subgroups was recorded. The electrogastrographic parameters (the postprandial instability coefficient of dominant frequency, the dominant power, and the power ratio) were significantly different between the subgroups, whereas the GE time did not differ significantly. In addition, EPS was characterized by a different gut peptide profile compared with PDS. Finally, neurotensin polymorphism was shown to be associated with neurotensin levels. This evidence deserves further studies in consideration of an analgesic role of neurotensin.

CONCLUSIONS

Analysis of gut peptide profiles could represent an interesting tool to enhance FD diagnosis and overcome limitations due to a distinction based solely on symptoms.

Neurotensin receptor binding abnormalities in the entorhinal cortex in schizophrenia and affective disorders

BACKGROUND

Convergent evidence from in vivo and in vitro studies of schizophrenia have implicated the mesial temporal lobe as a primary site of pathological change in this disorder. We have previously reported decreased neurotensin receptor density in layer II of the intermediate entorhinal cortex (ERC) in schizophrenia, a finding seen elsewhere but not seen in more caudal ERC.

METHODS

To study neuroanatomic and diagnostic specificity, we measured the density of neurotensin receptors in the intermediate and caudal ERC and hippocampal formation of schizophrenic, affective disorder control subjects, and normal control subjects. Slide-based radioligand binding was used to perform these studies.

RESULTS

Not only schizophrenic but also affective disorder subjects had decreased neurotensin receptor density in layer II of the intermediate ERC. Affective disorder subjects had significantly decreased neurotensin receptor density in layers V/VI of the intermediate ERC, and schizophrenic subjects trended in the same direction.

CONCLUSIONS

These findings demonstrate region-specific changes in neurotensin receptor binding levels in the mesial temporal lobe; however, there is no clear diagnostic specificity for these changes, because they were seen to varying degrees in both schizophrenia and affective disorders.