PT  - JOURNAL ARTICLE
AU  - E E Kousvelari
AU  - J W Kusiak
AU  - A R Hand
AU  - J Pitha
AU  - B J Baum
TI  - Bromoacetylalprenololmenthane: a potent irreversible antagonist of beta adrenergic elicited protein exocytosis in rat parotid cells.
DP  - 1983 Oct 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 238--243
VI  - 227
IP  - 1
4099  - http://jpet.aspetjournals.org/content/227/1/238.short
4100  - http://jpet.aspetjournals.org/content/227/1/238.full
SO  - J Pharmacol Exp Ther1983 Oct 01; 227
AB  - The interaction of bromoacetylalprenololmenthane (BrAlpM), an irreversible beta adrenergic receptor antagonist, with rat parotid acinar cells was studied in vitro. In the presence of BrAlpM, the rate of (-)-isoproterenol-induced exocrine secretion from cells, measured as percentage of amylase release, was markedly reduced. The concentration of (-)-isoproterenol required to elicit half-maximal protein secretion was about 100 times greater (5 microM) in the presence of 1 microM BrAlpM than in control incubations (0.05 microM). BrAlpM and propranolol were similar in their ability to inhibit parotid protein release (IC50 approximately 10(-7) M). To demonstrate that BrAlpM functioned as an irreversible beta adrenergic antagonist, cells were preincubated with BrAlpM for varying amounts of time and then washed three to six times before adding (-)-isoproterenol. At least 10 min preincubation was required to show irreversibility. Alprenolol, under the same preincubation conditions, was unable to inhibit amylase release. BrAlpM inhibited the binding of [3H]dihydroalprenolol to parotid beta adrenoreceptors over a concentration range similar to that required for inhibition of protein secretion. Cells incubated in the absence or presence of BrAlpM displayed a comparable morphologic appearance when viewed by light and electron microscopy. The degree of inhibition of isoproterenol-induced exocytosis of secretory granules by BrAlpM appeared to vary from cell to cell. These findings suggest that BrAlpM should be a useful probe to study beta adrenoreceptor function and metabolism in rat parotid acinar cells.