Patterns of adrenoceptor change during liver regeneration of the Wistar Kyoto rat: a binding study.
BACKGROUND
Adrenoceptors have been involved in the regulation of hepatocyte proliferation after partial hepatectomy, as well as in primary culture. This report characterizes alpha 1- and beta-adrenoceptor change during the time-course of liver regeneration in adult Wistar Kyoto rats.


METHODS
Saturation binding assays with [3H]prazosin or [3H]dihydroalprenolol (for alpha 1- and beta-adrenoceptors, respectively) were done in liver plasma membranes from 6-month-old rats subjected to 70% hepatectomy followed by hepatic regeneration.


RESULTS
[3H]Prazosin and [3H]dihydroalprenolol binding gave control Bmax values of 101 +/- 10 and 12 +/- 1 fmol/mg protein and Kd of 0.50 +/- 0.10 and 4.1 +/- 0.4 nM for alpha 1- and beta-adrenoceptors, respectively. alpha 1-Adrenoceptor number and Kd increased at 24 and 48 h and returned to control values at 72 and 96 h after surgery, whereas beta-adrenoceptors augmented at 48 and 72 h, with a Kd change at 24 and 48 h posthepatectomy.


CONCLUSIONS
These results suggest that dual control of alpha 1- and beta-adrenoceptor membrane expression could be involved in different steps during hepatocyte proliferation, and that Wistar Kyoto rats have a different adrenoceptor pattern expression from other rat strains.
Reyes-Salcido
V
V
Departamento de Farmacología y Toxicología, Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México.
Villalobos-Molina
R
R
D000317:Adrenergic alpha-Antagonists / Q000378:metabolism; D000319:Adrenergic beta-Antagonists / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D004082:Dihydroalprenolol / Q000378:metabolism; D006498:Hepatectomy; D007700:Kinetics; D008115:Liver Regeneration; D008297:Male; D011224:Prazosin / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D011941:Receptors, Adrenergic / Q000378:metabolism*
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D011941:Receptors, Adrenergic; D004082:Dihydroalprenolol; D011224:Prazosin