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Calcium‐inhibitable isoforms of adenylyl cyclase are not expressed in rat parathyroid
Author(s) -
Atchison Douglas K.,
Harding Pamela,
Beierwaltes William H.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1350-b
Subject(s) - adenylyl cyclase , medicine , endocrinology , gene isoform , western blot , calcium , polyclonal antibodies , calcium in biology , parathyroid gland , intracellular , chemistry , parathyroid chief cell , adcy9 , biology , microbiology and biotechnology , parathyroid hormone , antibody , biochemistry , gene , immunology , stimulation
A novel inverse relationship exists between intracellular calcium and cAMP formation in parathyroid glands. cAMP is the second messenger regulating PTH secretion. It is not known how increased intracellular calcium inhibits PTH secretion. However, there are two isoforms of adenylyl cyclase (AC) which are inhibited by calcium; types‐5 and 6. We hypothesized that in the rat, the parathyroid gland expresses one (or both) of the calcium‐inhibitable isoforms of AC, either type‐5 or 6, such that increased intracellular calcium would inhibit AC activity. Parathyroid glands were dissected from male Sprague‐Dawley rats. Western Blot analysis was performed on rat parathyroid homogenates using monoclonal antibodies against either AC‐5, AC‐6 or a polyclonal antibody against both AC‐5 and 6. Positive controls were run using heart and brain. We did not detect either AC‐5 or AC‐6 in rat parathyroid by Western blot analysis. Additionally, reverse transcription polymerase chain reaction (RT‐PCR) performed with AC‐5 specific primers on total RNA extracted from rat parathyroid did not indicate that AC‐5 was expressed in rat parathyroid gland. Thus, contrary to our hypothesis, we do not find evidence that either calcium‐inhibitable isoform of AC is expressed in rat parathyroid. (HFHS A10105)