Muscle as the primary site for testosterone to promote survival of axotomized motoneurons.
Whether the effect of testosterone to promote neuronal survival is expressed through its interaction with motoneurons or with effector muscles was investigated, since androgen receptors are present in both tissues. Following unilateral transection of the hypoglossal and facial nerves, hydroxyflutamide, an androgen receptor antagonist, was injected into the tongue muscles to block androgen receptor binding during the period when rats were treated with testosterone. The results indicate that hydroxyflutamide abolished testosterone effects on the hypoglossal but not the facial motor nucleus, indicating that androgen receptors in effector muscles are the primary mediators of hormonal actions. We postulate that testosterone may play a role in the production of muscle-derived factors which promote the survival of injured motoneurons.
Yu
W H
WH
Department of Cell Biology and Anatomical Sciences, City University of New York Medical School, New York 10031.
Cao
C G
CG
D000758:Anesthesia; D000818:Animals; D001369:Axons / Q000502:physiology*; D005154:Facial Nerve / Q000187:drug effects; D005260:Female; D005485:Flutamide / Q000031:analogs & derivatives / Q000494:pharmacology; D007002:Hypoglossal Nerve / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects*; D009132:Muscles / Q000294:innervation / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000494:pharmacology*
C014290:hydroxyflutamide; D013739:Testosterone; D005485:Flutamide