Lamellae have cores of vascular loose fibrous connective tissue enclosing small hemolymphatic vessels and are lined by simple cuboidal epithelial cells interspersed with granular gland
cells and mucus cells (Fig.
schneideri methanolic extract (50 [micro]g/mL of granular gland secretion) responded with an increase in quantal content (release of acetylcholine) that was inhibited with a non-toxic concentration of ouabain (1 [micro]g/mL), an inhibitor of the [Na.sup.+]/ [K.sup.+]-ATPase, after 5 min prior to incubation, indicating that these effects were prevented through the inhibition of [Na.sup.+]-[K.sub.+]-ATPase activity of muscle motor innervation.
schneideri granular gland (parotoid) secretion promotes a transitory decrease in the number of synaptic vesicles after a few minutes of incubation, interfering with synaptic neurotransmission.
Zasloff notes that the frog magainins are made throughout the animal's skin by the granular gland, which also produces neurotransmitters and hormones.
Perhaps this practice induces the frog to release magainins in the same way Zasloff has found that a shot of adrenaline will cause frogs in his laboratory to release the contents of their granular glands. The finding also suggests that synthesized magainins may have medicinal uses such as the treatment of burns.
When attacked, salamanders compress myoepithelial sheaths that surround granular glands in the skin .
These spots vary in brightness and number  and could potentially be areas with concentrated granular glands. Other newts are also known to contain regions of skin with high concentrations of toxin.
The toad genera Bufo and Rhinella, which belong to the Bufonidae family, possess various granular glands that secrete toxins for protection against predators.
Jared, "Cutaneous granular glands and amphibian venoms," Comparative Biochemistry and Physiology A: Physiology, vol.
The granular glands, which produce a biochemical mixture of poisonous or noxious secretions, tend to be more concentrated on the head and shoulder regions (Duellman & Trueb 1985; Zug et al.
Amphibian granular glands produce numerous biologically active compounds including; biogenic amines, peptides, proteins, bufadienolidies, tetrodotoxins, and lipophilic alkaloids (see review Daly et al.
Poison glands (also called granular glands
) release toxic substances that keep predators away.