Mechanism of action of 6, 7, 8, 9, 10, 12-hexahydro-azepino-[2, 1-b] quinazolin-12-one-(RLX)--a novel bronchodilator.

ABSTRACT

The present study presents a mode of action profile of RLX (6, 7, 8, 9, 10, 12-hexahydro-azepino-[2, 1-b]-quinazoline-12-one) a bronchodilator obtained by the chemical modification in the molecule of alkaloid vasicine (Ex Adhatoda vesica). The effect of RLX (p.o.) was observed on (a) mast cell degranulation, (b) release of histamine and prostaglandin E (PGE), (c) 45Ca uptake and (d) activities of cAMP phosphodiesterase (PDEase) and lipoxygenase enzymes in mesenteries/peritoneal mast cells/lung tissue homogenates in rats under systemic anaphylaxis. RLX (10 and 20 mg/kg) inhibited antigen-induced mast cell degranulation and released of histamine from target tissues. An increased outflow of PGE (lungs) and an inhibited 45Ca uptake (peritoneal mast cells) were noted. Lung PDEase and lipoxygenase activities were decreased. These results suggested that RLX could be acting like disodium cromoglycate and aminophyline with additional attributes its oral efficacy and long duration of action.