Altered levels of PGF in cat spinal cord tissue following traumatic injury.

Previous studies by others indicated that PGs were present in brain, spinal cord, and c.s.f. of several mammalian species. In the present study we compared levels of PGE and PGF by R.I.A. in spinal cord tissue from traumatized cats and cats pretreated with indomethacin prior to trauma to those of baseline and sham operated controls in order to assess for the first time, to our knowledge, whether meaningful changes in levels of PGE and PGF could be detected which might shed new light on the etiology of spinal cord trauma. Levels of PGF (nanograms/gram wet wt) in the cord segment immediately adjacent to the point of trauma were 8.05 +/- 1.50, and 13.13 +/- 1.38 for baseline and sham operated cats respectively. Spinal trauma led to more than a 100% increase in PGF levels to 29.26 +/- 3.58. Although pretreatment with indomethacin 30 min prior to trauma gave the expected blockade of the PGF response to trauma, a measurable level of PGF (2.55 +/- 0.17) was found in the cord after indomethacin. Cord levels of PGF declined after 3 hr in both sham operated and traumatized animals. PGF was maximally stimulated by trauma during the first 3 hr with little effect at 72 hr. Although carefully examined, PGE levels in cat spinal cord appeared to be virtually unaffected by trauma. These findings clearly demonstrate for the first time that traumatic injury to the spinal cord is accompanied by marked increases in PG levels at the site of trauma, and that the observed elevation in PGF in response to trauma can be blocked by indomethacin in vivo. Whether PGF changes are causally related to the etiology of spinal cord trauma, or merely represent a manifestation of PG release as a result of non-specific tissue injury, remains to be seen.