Effect of carbachol on 45Ca uptake and protein secretion in rat lacrimal gland

Carbachol stimulates 45Ca uptake and protein secretion in rat lacrimal glands. At low concentration (10-8 M) atropine inhibits these effects but phentolamine and propranolol (10-5 M) are ineffective. The optimum response in both processes is obtained at the same concentration (10-6 M) of the cholinergic agonist. Vinblastine (10-4 M) reduces protein discharge induced by carbachol without modifying the uptake of 45Ca stimulated by the parasympathetic mediator. Calcium influx is proposed as the primary effect of cholinergic inducers in secretory processes.