title: Quantification of thyrotropin-releasing hormone changes and serotonin content changes following graded spinal cord injury.
abstract: Thyrotropin-releasing hormone (TRH) and serotonin (5-HT) are well known as neurotransmitters of descending bulbo-spinal tracts. 5-HT uptake caudal to (5-HT decreased) graded spinal lesions has been measured in rats and dogs and significantly correlated with the degree of cord injury. We studied 5-HT content via high-pressure liquid chromatography and radioimmunoassay measurements of TRH in dog spinal cord, both rostral and caudal, to 6 week T6 spinal transection (T) (n = 7) or T6 hemisections (H) (n = 7). Sham controls (n = 7) were used. Mean 5-HT content values were (pmole/mg): rostral sham 1.25 +/- 0.02, caudal sham 1.35 +/- 0.17, rostral T 2.65 +/- 0.36, caudal T 0.19 +/- 0.06, rostral H 2.1 +/- 0.22, and caudal H 1.0 +/- 0.31. A significant decrease in 5-HT caudal to transection versus control (P < 0.001) was seen. A trend for decreased 5-HT caudal to hemisection versus control (P < 0.1) was also seen. Mean TRH levels (pg/mg protein) were: rostral sham 40.02 +/- 18.47, caudal sham 30.61 +/- 10.03, brainstem sham 18.9 +/- 5.13, rostral T 52.4 +/- 21.34, caudal T 3.52 +/- 1.87, brainstem T 19.25 +/- 4.11, rostral H 43.45 +/- 18.61, caudal H 14.24 +/- 5.7, and brainstem H 21.89 +/- 1.23. Significant decreases for caudal TRH transection versus controls (P < 0.001) and for caudal TRH hemisection versus controls (P < 0.02) were seen. A significant difference between caudal hemisection and caudal transection TRH levels (P < 0.001) was seen.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Indiana University Medical Center, Indianapolis, USA.
authors.forename: S
authors.initials: S
authors.lastname: Shapiro
authors.forename: M
authors.initials: M
authors.lastname: Kubek
authors.forename: E
authors.initials: E
authors.lastname: Siemers
authors.forename: E
authors.initials: E
authors.lastname: Daly
authors.forename: J
authors.initials: J
authors.lastname: Callahan
authors.forename: T
authors.initials: T
authors.lastname: Putty
mesh_terms: D000818:Animals; D001933:Brain Stem / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D005260:Female; D011863:Radioimmunoassay; D012701:Serotonin / Q000032:analysis / Q000378:metabolism*; D013116:Spinal Cord / Q000737:chemistry* / Q000378:metabolism; D013119:Spinal Cord Injuries / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000032:analysis / Q000378:metabolism*
chemical_list: D012701:Serotonin; D013973:Thyrotropin-Releasing Hormone