Abstract

Neuronostatin, derived from the somatostatin preprohormone, is a recently described peptide that is produced by several tissues involved in cardiovascular regulation and metabolism, including the hypothalamus. Injection of neuronostatin into the lateral cerebroventricle led to a dose-related increase in mean arterial pressure (MAP) in rats. Any attempt to inhibit the production of neuronostatin would alter somatostatin production as well, making determination of the physiological relevance of the peptide's pharmacologic effects by compromise of production approaches impossible. Therefore, we employed an alternative approach to identify and compromise the production of the neuronostatin receptor. Because neuronostatin was shown to signal via a PKA-dependent mechanism, we hypothesized that the neuronostatin receptor was a G protein-coupled receptor (GPCR), in particular, one of the orphan GPCRs for which the ligand is unknown. Therefore, we screened neuronostatin-responsive tissues, including hypothalamus, heart, pancreatic α-cells, and the gastric tumor cell line KATOIII, for expression of orphan GPCRs. Four orphan GPCRs were expressed by all cell types, including GPR56 and GPR107. Knockdown of GPR107, but not GPR56 or GPR146, led to a loss of responsiveness to neuronostatin by KATOIII cells. Rats injected with siRNA directed against GPR107 (2 μg/day for 2 days) into the lateral cerebroventricle did not exhibit an increase in MAP in response to neuronostatin treatment. Rats with compromised GPR107 expression also displayed blunted reactivity in a baroreflex sensitivity test, indicating that GPR107 and neuronostatin may be important regulators of cardiovascular function. Thus, GPR107 is a promising candidate receptor for neuronostatin, and neuronostatin, interacting with GPR107, may play an important role in the central control of cardiovascular function. © 2012 the American Physiological Society.

Department(s)

Biological Sciences

Publication Status

Open Access

Comments

National Institutes of Health, Grant F32HL006623

Keywords and Phrases

Central control of blood pressure; Neuronostatin; Orphan G protein-coupled receptor

International Standard Serial Number (ISSN)

1522-1490; 0363-6119

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2025 American Physiological Society, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Nov 2012

PubMed ID

22933024

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