The effects of epinephrine, norepinephrine, and carbachol on oxygen consumption in rat sublingual gland slices.

Epinephrine and carbachol, but not norepinephrine, significantly stimulated oxygen consumption in rat sublingual gland slices. The response to epinephrine was blocked by phentolamine and yohimbine, while propranolol and prazosin did not affect it. The response to carbachol was blocked by atropine. Also, oxygen consumption induced by both epinephrine and carbachol was inhibited by verapamil. These findings suggest that epinephrine enhanced oxygen consumption in sublingual gland slices by activation of alpha 2-adrenergic receptors, while carbachol activated muscarinic receptors; activation of both receptors mediated the respiratory response by facilitating the entry of extracellular Ca.