In:
The Journal of Neuroscience, Society for Neuroscience, Vol. 18, No. 13 ( 1998-07-01), p. 4938-4945
Abstract:
Somatostatin is known to mediate its actions through five G-protein-coupled receptors (sst 1 –sst 5 ). We have studied the expression of the sst 1 receptor in the rat hypothalamus by using a subtype-specific antiserum. In Western blotting, the antiserum reacted specifically with a band with an apparent molecular weight of 80,000 in membranes prepared from hypothalamic tissue. The localization of the sst 1 receptor was investigated by immunohistochemistry in hypothalamus sections. Additionally, an immunofluorescent double-labeling was performed for the sst 1 receptor and somatostatin. Light microscopy revealed that the sst 1 receptor is located in perikarya and nerve fibers in the rostral periventricular area surrounding the third ventricle as well as in nerve fibers projecting from the perikarya to the external layer of the median eminence. In these neuronal structures, sst 1 immunoreactivity was found to be colocalized with somatostatin. Furthermore, the location of sst 1 receptors was studied by immunoelectron microscopy in the median eminence. In the external layer, receptor immunoreactivity was confined to nerve terminals. Immunoreactive nerve terminals were seen to make synapse-like junctions with other both stained and unstained nerve terminals. Thus, the sst 1 receptor is present in the classic somatostatinergic hypothalamic parvocellular system inhibiting hormone secretion from the anterior pituitary gland. These findings indicate that the sst 1 receptor may act as an autoreceptor and inhibit the release of somatostatin from periventricular neurons projecting to the median eminence.
Type of Medium:
Online Resource
ISSN:
0270-6474
,
1529-2401
DOI:
10.1523/JNEUROSCI.18-13-04938.1998
Language:
English
Publisher:
Society for Neuroscience
Publication Date:
1998
detail.hit.zdb_id:
1475274-8
SSG:
12
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