ISSN:
1573-6903
Keywords:
β-adrenoceptor
;
β-adrenoceptor subtypes
;
neocortical explants
;
isoproterenol
;
down-regulation
;
development
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The presence and time-course of β-adrenoceptor density in cultured explants of neocortex obtained from 6-day-old rat pups were investigated using a [125I]ICYP binding assay. A delayed, but more pronounced, increase in the receptor expression was observed as compared to the situation previously described in vivo. These changes only occurred for the β1-subtype of the receptor, whereas the β2-subtype binding remained constant up to 3 weeks in vitro. The delay of β1-adrenoceptor expression may be due to the incomplete presence of the proper maturational input, and the late enhancement of receptor expression to upregulation related to the absence in vitro of noradrenergic input. Decreased β-adrenoceptor levels could be induced by chronic treatment of the β-agonist isoproterenol (1 μM) introduced either for 3 or 13 days. Again, changes in density were found only for the β1-adrenoceptor binding sites. There is no reduction of receptor density following return to control conditions for 10 days after a 3-day treatment with isoproterenol, demonstrating the ability of this model to attain its final receptor density notwithstanding the developmental insult.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01694539
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