Cholecystokinin-8-like-immunoreactive fibers in rat lumbosacral autonomic regions are sexually dimorphic and altered by a reduction of androgen receptors.
Cholecystokinin-8-like-immunoreactive (CCK-8-LI) fibers in laminae VII and X of the rat lumbosacral spinal cord demarcate the position of preganglionic autonomic neurons. This investigation reveals that adult male Sprague-Dawley, or King-Holtzman/Sprague-Dawley rats contain more CCK-8-LI fibers in lumbosacral laminae VII and X than adult females. Furthermore, testicular feminization mutation male rats (which lack 85-90% of their functional androgen receptors) contain fewer CCK-8-LI fibers than normal male or female rats, with the amount of CCK-8-LI being reduced to a greater extent in the sympathetic vs. the parasympathetic regions of the lumbosacral spinal cord. Thus, CCK-8-LI in testicular feminization mutation male rats has a distinctly female-like pattern. These results suggest that testosterone is a regulatory factor for CCK-8-LI fibers found in laminae VII and X of the lumbosacral spinal cord. Sexual dimorphism in lumbosacral CCK-8-LI fibers may contribute to modulating the final common pathway which differentially regulates the reproductive organs and stereotypic reproductive behavior, and may be involved with the sex differences described for pain.
Phan
D C
DC
Department of Anatomy and Center for Neuroscience, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
Newton
B W
BW
D013734:Androgen-Insensitivity Syndrome / Q000378:metabolism; D000818:Animals; D017776:Autonomic Pathways / Q000378:metabolism*; D005260:Female; D008161:Lumbosacral Region; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011944:Receptors, Androgen / Q000378:metabolism*; D012737:Sex Factors; D012844:Sincalide / Q000378:metabolism*; D013116:Spinal Cord / Q000378:metabolism*
D011944:Receptors, Androgen; D012844:Sincalide