Identification in islets of Langerhans of a new rat alpha 2-adrenergic receptor

• Published in: Diabetes (New York, N.Y.) Vol. 43; no. 1; pp. 127 - 136
• Main Authors: Wang, S Y, Pilkey, D T
• Format: Journal Article
• Language: English
• Published: United States American Diabetes Association 01.01.1994
• Subjects: Adrenergic receptors; Aging - metabolism; Amino Acid Sequence; Animals; Base Sequence; Cell Line; Cloning, Molecular; DNA Primers; DNA, Complementary - biosynthesis; Epinephrine; Female; Gene Library; Humans; Islands of Langerhans; Islets of Langerhans; Islets of Langerhans - growth & development; Islets of Langerhans - metabolism; Male; Molecular Sequence Data; Pancreas - growth & development; Pancreas - metabolism; Physiological aspects; Polymerase Chain Reaction; Rats; Rats, Sprague-Dawley; Receptors; Receptors, Adrenergic, alpha-2 - analysis; Receptors, Adrenergic, alpha-2 - biosynthesis; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Swine
• ISSN: 0012-1797; 1939-327X; 0012-1797
• DOI: 10.2337/diabetes.43.1.127

Identification in islets of Langerhans of a new rat alpha 2-adrenergic receptor. S Y Wang and D T Pilkey Gerontology Division, Beth Israel Hospital, Boston, MA 02215. Abstract The islets of Langerhans are richly innervated, and an inhibitory effect on insulin secretion, mediated through alpha 2-adrenergic receptors, appears to be an important physiological neural modulator of beta-cell function. An alpha 2-receptor was cloned from isolated newborn rat islets using a polymerase chain reaction (PCR) approach. This receptor was shown by sequencing to be a new rat alpha 2-receptor very similar to the human alpha 2-C2 receptor. No other alpha 2-receptor subtype was identified in normal islets by the PCR using alpha 2-receptor primers. This was also the only alpha 2-receptor subtype present in the exocrine pancreas and liver. In contrast, in the beta-cell line, beta TC3, the alpha 2-C2 receptor was not detected, but the alpha 2-C4 and alpha 2-C10 receptor subtypes were detected. It is suggested that the alpha 2-C2 subtype may be the principal alpha 2-receptor mediating inhibitory autonomic nervous system activity in the gastrointestinal tract. A comparison of the rat islet, pancreas, and liver alpha 2-receptor sequences reported here with previously reported alpha 2-receptor sequences indicates that the rat islet alpha 2-receptor is not the rat alpha 2-C2 homologue previously denoted as RNG alpha 2, but is a new, fourth rat subtype with an even higher similarity to the human alpha 2-C2 receptor.