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Overexpression of alpha 2-adrenergic receptors in fetal rat heart: receptors in search of a function.

Publication ,  Journal Article
Lin, W; Seidler, FJ; McCook, EC; Slotkin, TA
Published in: J Dev Physiol
April 1992

alpha 2-Adrenergic receptors are transiently overexpressed by many types of developing cells. In the current study, the developmental profile and cellular function of these receptors were examined in the fetal and neonatal rat heart. alpha 2-Receptors, assessed with [3H]rauwolscine binding, were extremely high in fetal hearts on gestational day 19, 30-fold higher than values seen in adults. Receptor binding decreased by two-thirds by gestational day 21 and dropped by half again by postnatal day 3. To assess potential cellular functions controlled by the alpha 2-receptors, the capability of an alpha 2-agonist (clonidine) to inhibit membrane-associated adenylate cyclase activity was measured in three different settings: basal enzyme activity, the enzymatic response to isoproterenol (dependent upon beta-receptor linkages to the regulatory protein, Gs), and the response to forskolin (independent of receptor-Gs interactions). Despite the high number of alpha 2-receptors in fetal hearts, clonidine failed to alter any of the adenylate cyclase activity measures. In light of the postulated role of alpha 2-receptors in the maintenance of fetal/neonatal atrioventricular conduction, the excess alpha 2-receptors are probably linked to other cellular events, such as movement of calcium into the cell.

Duke Scholars

Published In

J Dev Physiol

ISSN

0141-9846

Publication Date

April 1992

Volume

17

Issue

4

Start / End Page

183 / 187

Location

England

Related Subject Headings

  • Yohimbine
  • Receptors, Adrenergic, alpha
  • Rats, Sprague-Dawley
  • Rats
  • Myocardium
  • Isoproterenol
  • In Vitro Techniques
  • Gestational Age
  • Fetal Heart
  • Colforsin
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Lin, W., Seidler, F. J., McCook, E. C., & Slotkin, T. A. (1992). Overexpression of alpha 2-adrenergic receptors in fetal rat heart: receptors in search of a function. J Dev Physiol, 17(4), 183–187.
Lin, W., F. J. Seidler, E. C. McCook, and T. A. Slotkin. “Overexpression of alpha 2-adrenergic receptors in fetal rat heart: receptors in search of a function.J Dev Physiol 17, no. 4 (April 1992): 183–87.
Lin W, Seidler FJ, McCook EC, Slotkin TA. Overexpression of alpha 2-adrenergic receptors in fetal rat heart: receptors in search of a function. J Dev Physiol. 1992 Apr;17(4):183–7.
Lin, W., et al. “Overexpression of alpha 2-adrenergic receptors in fetal rat heart: receptors in search of a function.J Dev Physiol, vol. 17, no. 4, Apr. 1992, pp. 183–87.
Lin W, Seidler FJ, McCook EC, Slotkin TA. Overexpression of alpha 2-adrenergic receptors in fetal rat heart: receptors in search of a function. J Dev Physiol. 1992 Apr;17(4):183–187.

Published In

J Dev Physiol

ISSN

0141-9846

Publication Date

April 1992

Volume

17

Issue

4

Start / End Page

183 / 187

Location

England

Related Subject Headings

  • Yohimbine
  • Receptors, Adrenergic, alpha
  • Rats, Sprague-Dawley
  • Rats
  • Myocardium
  • Isoproterenol
  • In Vitro Techniques
  • Gestational Age
  • Fetal Heart
  • Colforsin