Relationship between neuronal activity and substance P-immunoreactivity in the rat spinal cord during acute and persistent myositis.
The spinal level of substance P (SP) is assumed to be an important determinant of neuronal activity under pathophysiological conditions. In rat dorsal horn neurones, impulse activity was studied during a carrageenan-induced acute (2-8 h) and a Freund's adjuvant-induced persistent (12 days) myositis and compared with the spinal substance P-immunoreactivity (SP-IR) of the same animals. Myositis-induced changes in responsiveness of the neurones reached a maximum within 2-8 h, whereas background activity of the neurones was highest after 12 days of myositis. The area of SP-IR in the superficial dorsal horn decreased during acute and persistent myositis and the integrated density of the staining was largely unchanged. The difference in time-course between neuronal activity and SP-IR suggest that during persistent myositis factors other than SP gain more influence on the behaviour of the neurones.
Hoheisel
U
U
Institut für Anatomie und Zellbiologie, Universität Heidelberg, Germany.
Kaske
A
A
Mense
S
S
D000208:Acute Disease; D000818:Animals; D002351:Carrageenan / Q000494:pharmacology; D002908:Chronic Disease; D004558:Electric Stimulation; D005620:Freund's Adjuvant / Q000494:pharmacology; D008297:Male; D009220:Myositis / Q000139:chemically induced / Q000503:physiopathology*; D009474:Neurons / Q000378:metabolism* / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism* / Q000502:physiology; D013373:Substance P / Q000378:metabolism*; D013997:Time Factors
D013373:Substance P; D002351:Carrageenan; D005620:Freund's Adjuvant