Allopregnanolone suppresses mechanical allodynia and internalization of neurokinin-1 receptors at the spinal dorsal horn in a rat postoperative pain model.
Fujita M, Fukuda T, Sato Y, Takasusuki T, & Tanaka M. (2018). Korean J Pain, 31 (1):10-15.
The Neurokinin-1 (NK-1; NK1R) receptor is a G-protein-coupled receptor characterized by seven transmembrane helices which preferentially binds the neuropeptide substance P. The NK-1 receptor (also known as the substance P receptor) plays a key role in pain and inflammation. Studies also implicate NK-1 receptors in depression and the growth of brain tumors.
Green: NK-1R, Red: NeuN.
(A) An image of NK-1r in the lamina I. Notice the presence of NK-1r on a neuron membrane and the lack of NK-1r containing endosomes in the cytoplasm. (B) An image of incision-induced NK-1r internalization. Notice the presence of NK-1r containing endosomes in the cytoplasm. Scale bar is 10 mm.
The antibody used in this research (Cat. #AB-N33AP) recognizes the NK-1 receptor in rat, dog, and human. This antibody was developed in rabbit using a synthetic peptide corresponding to an amino acid sequence at the C-terminus of dog NK-1 receptor conjugated to bovine thyroglobulin with glutaraldehyde. The peptide sequence has a high degree of homology to other species such as human, mouse, rat and guinea pig. The antibody is routinely tested by immunohistochemistry and flow cytometry.
Applications include immunohistochemistry, flow cytometry, immunoblotting, and ELISA.
The objective in the study published by Fujita et al. was to identify a new strategy for postoperative pain management, this study investigated the analgesic effects of allopregnanolone (Allo) in an incisional pain model, and its effects on the activities of the primary afferent fibers at the dorsal horn.
Summary: Systemic administration of Allopregnanolone inhibited mechanical allodynia and activities of the primary afferent fibers at the dorsal horn in a rat postoperative pain model. Allopregnanolonewas proposed as a candidate for postoperative pain management.
Dose: Fluorescence immunohistochemistry: Six sections per animal were labeled with primary antiserum, rabbit anti-NK-1R (1:3,000), Cat. #AB-N33AP.