Localization of Cannabinoid Receptor 1 (CB1) in Submandibular and Sublingual Salivary Glands of Mice throughout Postnatal Development

Abstract

SUMMARY:In view of the fact that human marijuana users often show dry mouth symptom, the present study was attempted to examine the localization of CB1, which was originally identified in brain, in the submandibular and sublingual salivary glands of postnatal developing male mice by immunohistochemistry. In submandibular gland, CB1-immunoreactivity was positive in a majority of acinar cells in forms of granular appearance in their apical cytoplasm, while it was negative in the ducts at newborn stage. The immunoreactivity decreased in the acinar cells at P1W and no immunoreactivity was detected in the acinar cells at P3W and thereafter. The immunoreactivity was positive in ductal cells at P3W and it remained positive thereafter until P8W stage. The immunoreaction was distinct on the apical plasmalemma of the intercalated ductal cells, while it was distinct on the basal plasmalemma of the granular convoluted ductal cells. The enhanced immunostaining on the lateral plasmalemma of the granular ductal cells was discerned only on P6W. In sublingual gland, CB1-immunoreactivity was detected in the demilune acinar cells and ductal cells only on P4W. Furthermore, CB1-immunoreactivity was shown to occur in the salivary ganglionic neurons, suggesting the CB1-inhibitory action in the saliva secretion through the parasympathetic nervous transmission.

The presence and distribution of cannabinoid type 1 and 2 receptors in the mandibular gland: The influence of different physical forms of diets on their expression in piglets

“…Several studies on laboratory animals have shown the presence of cannabinoid receptors in the secretory portion, of the major salivary glands, which controlled the quality and quantity of saliva produced (Hipkaeo, Watanabe, & Kondo, 2015;Kopach et al, 2012). Similar observations were found in humans where the prolonged use of marijuana decreased saliva secretion.…”

“…Among the various regulatory molecules identified to date in the mandibular gland, the endocannabinoids, such as anandamide, as ligands for specific cognate receptors composing the so‐called cannabinoid system, might also have a role in the control of salivary secretion. Several studies on laboratory animals have shown the presence of cannabinoid receptors in the secretory portion, of the major salivary glands, which controlled the quality and quantity of saliva produced (Hipkaeo, Watanabe, & Kondo, ; Kopach et al., ). Similar observations were found in humans where the prolonged use of marijuana decreased saliva secretion.…”

The Current and Potential Application of Medicinal Cannabis Products in Dentistry

“…Cannabinoid receptors such as the transient receptor potential vanilloid channel type 1 (TRPV 1 ), cannabinoid receptors type 1(CB 1 ) and cannabinoid receptors type 2 (CB 2 ) in addition to other cannabinoid receptors located in the salivary glands may be novel therapeutic targets in the treatment of certain oral diseases [ 156 , 157 , 158 ]. Cannabinoid receptors located in salivary glands (particularly submandibular acinar cells) have also been implicated in the regulation of salivation and saliva content and thus may even be useful in the treatment of Xerostomia (“dry-mouth”) [ 158 , 159 ].…”

“…Cannabinoid CB 1 and CB 2 receptor are up-regulated in certain cancer types and thus, may be potential targets to exploit in the treatment of cancer and other diseases [ 199 ]. Multiple cannabinoids have demonstrated antioxidant, anti-metastatic, anti-tumorigenic, apoptotic and anti-angiogenic properties in various cancer cell lines and thus may have therapeutic benefits in treating oral cancers [ 104 , 157 , 200 , 201 , 202 , 203 , 204 , 205 , 206 , 207 , 208 , 209 ]. Table 4 lists particular potential applications of secondary metabolites against oral and dental diseases.…”

Temporal involvement of phosphatidylinositol 4‐phosphate 5‐kinase γ in differentiation of Z‐bands and myofilament bundles as well as intercalated discs in mouse heart at mid‐gestation

“…For the PI turnover to function effectively, individual PI molecules must be compartmentalized properly both spatially and temporally within various membranes of cells. This compartmentalization is probably the case for enzyme molecules responsible for synthesis of PIs, although most, if not all, of the enzymes are basically present in the cytosol and they move back and forth to the membranes on demand for synthesizing (Hipkaeo & Kondo, 2023).…”