EFFECTS OF CASTRATION ON CANNABINOID CB₁ RECEPTOR EXPRESSION AND ON THE BIOLOGICAL ACTIONS OF CANNABINOID IN THE PAROTID GLAND

Abstract

In the present study, we examined whether cannabinoid receptor expression and the effects of receptor stimulation vary as a function of gonadal status in a peripheral tissue, namely the male rat parotid gland. Four groups of male rats were studied: gonadal intact, castrated, castrated testosterone (1 mg/100 g bodyweight) treated and gonadal intact testosterone treated. 2. The results showed that the density of CB(1) receptors decreased after castration and that receptor density was restored to control values after testosterone treatment. This decrement was associated with a decrease of anandamide (10(-10) to 10(-5) mol/L)-induced cAMP accumulation and amylase release without changes in the anandamide-induced inhibition of Na(+)/K(+)-ATPase activity. 3. Castration did not modify either the subtype of cannabinoid receptor involved in the actions of anandamide or drug affinity for the receptor. 4. The mechanism underlying anandamide-induced cAMP accumulation, amylase release and inhibition of Na(+)/K(+)-ATPase activity, namely through the activation of adenylyl cyclase, was the same in control and castrated rats. 5. Basal cAMP accumulation, amylase release and Na(+)/K(+)-ATPase activity were not altered by castration. 6. Castration had no effect on the concentration of total protein. 7. It can be concluded that CB(1) cannabinoid receptor expression is regulated by testosterone in male rat parotid gland and this has functional implications for cAMP accumulation and amylase release.

Immunohistochemical localization of CB1 receptor in canine salivary glands

“…This study confirms the presence of the CB1 receptor in the major salivary glands of dogs and that CB1 localizes to the cells of striated ducts, as previously demonstrated in rats (Prestifilippo et al 2006;Busch et al 2006). The immunohistochemical positive reaction inside the cells was localized on or near to the apical membrane.…”

“…Recently, interest in these substances has increased as a consequence of the cloning of two receptors specific to cannabinoids, cannabinoid receptor type 1 (CB1) and CB2, in humans (Munro et al 1993) and laboratory animals (Matsuda et al 1990), and the discovery of endogen substances, commonly indicated as endocannabinoids (Busch et al 2006), that bind to these receptors.…”

Early Cannabis Use, Polygenic Risk Score for Schizophrenia and Brain Maturation in Adolescence

“…Furthermore, limited evidence supports the possible effects of testosterone on potentiating the action of cannabinoid type 1 receptor agonists on presynaptic inhibition of excitatory inputs in vitro 57 and on transcriptional up-regulation of the CNR1 gene. 58,59 …”

Differential Expression of Brain Cannabinoid Receptors between Repeatedly Stressed Males and Females may Play a Role in Age and Gender-Related Difference in Traumatic Brain Injury: Implications from Animal Studies

“…Sex hormones during the estrous cycle have been linked with brain CB 1 receptor density, which is reduced in the limbic forebrain and hypothalamus after ovariectomy and castration but can be restored after estradiol, progesterone, and testosterone administration in intact and ovariectomized/castrated rats (80–84). High levels of stress-induced corticosteroid secretion and base-line corticosteroids as well as slow clearance of corticosteroids could lead to reduced CB 1 receptor levels in stressed females (85, 86).…”