Enhancement by Epinephrine of Benzylpenicillin Transport in Rat Small Intestine
The perfusion of rat small intestinal lumen with epinephrine (0.1 mM) resulted in a significant increase in the amount of benzylpenicillin (BP) transported from the mucosal to the serosal side. In this study, the perfusion of the lumen with phenylephrine, clonidine, dobutamine, or salbutamol had no...
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Published in | The Journal of pharmacology and experimental therapeutics Vol. 293; no. 1; pp. 128 - 135 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Pharmacology and Experimental Therapeutics
01.04.2000
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Subjects | |
Online Access | Get full text |
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Summary: | The perfusion of rat small intestinal lumen with epinephrine (0.1 mM) resulted in a significant increase in the amount of
benzylpenicillin (BP) transported from the mucosal to the serosal side. In this study, the perfusion of the lumen with phenylephrine,
clonidine, dobutamine, or salbutamol had no effect on BP transport. However, the combinations of phenylephrine and isoproterenol,
clonidine and isoproterenol, and phenylephrine and salbutamol increased the BP transport to a similar extent as that observed
with epinephrine alone. Tolazolin or propranolol inhibited the epinephrine-induced increase in BP transport. An increase in
the intracellular concentration of cAMP in conjunction with specific activation of either α 1 - or α 2 -adrenoceptors induced an increase in BP transport similar to that observed in response to epinephrine alone. Staurosporine
or N -[2-(methylamino)ethyl]-5-isoquinolinesulfonamide abolished the epinephrine-induced increase in BP transport. Peptides or
either zwitterionic or anionic cephalosporins also blocked the effect of epinephrine on BP transport. The extent of BP uptake
into brush border or basolateral membrane vesicles prepared from epinephrine-perfused intestinal loops was markedly greater
than that into vesicles prepared from control loops. The perfusion of intestinal lumen with carbonyl cyanide p -trifluoromethoxy phenylhydrazone, amiloride, or ouabain inhibited epinephrine-induced BP transport. These results indicate
that the interaction of epinephrine with both β 2 -adrenoceptors and either α 1 - or α 2- adrenoceptors markedly stimulates the BP transport, an effect likely mediated by the enhancement of the function in the brush
border membrane of intestinal epithelial cells coupled with the generation of an H + gradient. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3565 1521-0103 |