Reduced Noradrenergic Signaling in the Spleen Capsule in the Absence of CB1 and CB2 Cannabinoid Receptors
ORCID
Kaplan: https://orcid.org/0000-0002-1992-4145
MSU Affiliation
College of Veterinary Medicine; Department of Basic Sciences
Creation Date
2026-03-30
Abstract
The spleen is a visceral organ that contracts during hypoxia to expel erythrocytes and immune cells into the circulation. Spleen contraction is under the control of noradrenergic sympathetic innervation. The activity of noradrenergic neurons terminating in the spleen capsule is regulated by α2-adrenergic receptors (AR). Interactions between endogenous cannabinoid signaling and noradrenergic signaling in other organ systems suggest endocannabinoids might also regulate spleen contraction. Spleens from mice congenitally lacking both CB1 and CB2 cannabinoid receptors (Cnr1 -/- /Cnr2 -/- mice) were used to explore the role of endocannabinoids in spleen contraction. Spleen contraction in response to exogenous norepinephrine (NE) was found to be significantly lower in Cnr1 -/- /Cnr2 -/- mouse spleens, likely due to decreased expression of capsular α1AR. The majority of splenic Cnr1 mRNA expression is by cells of the spleen capsule, suggestive of post-synaptic CB1 receptor signaling. Thus, these studies demonstrate a role for CB1 and/or CB2 in noradrenergic splenic contraction.
Publication Date
6-10-2016
Publication Title
Journal of Neuroimmune Pharmacology
Publisher
Springer
First Page
669
Last Page
679
Recommended Citation
Simkins, T.J., Fried, D., Parikh, K. et al. Reduced Noradrenergic Signaling in the Spleen Capsule in the Absence of CB1 and CB2 Cannabinoid Receptors. J Neuroimmune Pharmacol 11, 669–679 (2016). https://doi.org/10.1007/s11481-016-9689-2
