Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.5.4 (SOR)
 720 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Maternal deprivation in rats specifically leads to a vulnerability to opiate dependence. However, the impact of cannabis exposure during adolescence on this opiate vulnerability has not been investigated. Chronic dronabinol (natural delta-9 tetrahydrocannabinol, THC) exposure during postnatal days 35-49 was made in maternal deprived (D) or non-deprived (animal facility rearing, AFR) rats. The effects of dronabinol exposure were studied after 2 weeks of washout on the rewarding effects of morphine measured in the place preference and oral self-administration tests. The preproenkephalin (PPE) mRNA levels and the relative density and functionality of CB1, and mu-opioid receptors were quantified in the striatum and the mesencephalon. Chronic dronabinol exposure in AFR rats induced an increase in sensitivity to morphine conditioning in the place preference paradigm together with a decrease of PPE mRNA levels in the nucleus accumbens and the caudate-putamen nucleus, without any modification for preference to oral morphine consumption. In contrast, dronabinol treatment on D-rats normalized PPE decrease in the striatum, morphine consumption, and suppressed sensitivity to morphine conditioning. CB1 and mu-opioid receptor density and functionality were not changed in the striatum and mesencephalon of all groups of rats. These results indicate THC potency to act as a homeostatic modifier that would worsen the reward effects of morphine on naive animals, but ameliorate the deficits in maternally D-rats. These findings point to the self-medication use of cannabis in subgroups of individuals subjected to adverse postnatal environment.
 ...
PMID:Adolescent exposure to chronic delta-9-tetrahydrocannabinol blocks opiate dependence in maternally deprived rats. 1955 15

Whether adolescent exposure to chronic delta-9-tetrahydrocannabinol (THC) facilitates progression to opioid consumption is still controversial. In a maternal deprivation model (3 h daily from postnatal day 1-14), we previously reported that adolescent exposure to chronic THC blocks morphine dependence in maternally deprived (D) rats. Owing to the existence of a functional cross-interaction between the opioid and cannabinoid systems in reward, we evaluated if the vulnerability to opiate reward in D rats, may involve an alteration of the endocannabinoid system. Anandamide and 2-arachidonoylglycerol (2-AG), were quantified in the striatum and mesencephalon of adolescent and adult D and non-deprived (animal facility rearing, AFR) rats by isotope dilution liquid chromatography-mass spectrometry. Oral morphine self-administration behavior was analyzed for 14 weeks, 24 days after chronic injection of the cannabinoid CB1 receptor antagonist/inverse agonist, SR141716A (3 mg/kg) for 2 weeks during adolescence (PND 35-48). Adolescent D rats exhibited higher basal levels of anandamide than adolescent AFR rats in the nucleus accumbens (38%), the caudate-putamen nucleus (62%) and the mesencephalon (320%), whereas adult D rats showed an increase of anandamide and 2-AG levels in the nucleus accumbens (50% and 24%, respectively) and of 2-AG in the caudate-putamen nucleus (48%), compared to adult AFR rats. Chronic administration of SR141716A to adolescent D rats blocked the escalation behavior in the morphine consumption test. Our data suggest that altered brain endocannabinoid levels may contribute to the escalation behavior in the morphine consumption test in a maternal deprivation model.
 ...
PMID:Possible involvement of endocannabinoids in the increase of morphine consumption in maternally deprived rat. 2308 38