Permeability of epidural somatostatin and morphine into the intrathecal space of dogs.
In an in vivo saline perfusate of the intrathecal space of 6 dogs, the concentration of somatostatin was determined by radioimmunoassay before and over 2 h after epidural administration of 3 mg somatostatin. The total recovered amount of somatostatin was negligible, about 0.02%. However, within 50 min after the bolus epidural injection of somatostatin, the concentration per ml perfusate increased from 0.1 +/- 0.02 ng/ml to 138 +/- 102 ng/ml (P less than 0.001) and declined to 4 +/- 1.7 ng/ml after 120 min. This increase of the somatostatin concentration by 3 orders of magnitude might explain why epidurally administered somatostatin is effective in treatment of acute and chronic pain. In a control investigation with epidural morphine in another 6 dogs to prove the feasibility of the method, the total recovered amount of morphine in the intrathecal perfusate over 2 h was about 12%.
Chrubasik
J
J
Bonath
K
K
Cramer
H
H
Rissler
K
K
Wünsch
E
E
D000818:Animals; D004285:Dogs; D007278:Injections, Spinal; D009020:Morphine / Q000008:administration & dosage / Q000378:metabolism*; D010539:Permeability; D011863:Radioimmunoassay; D013004:Somatostatin / Q000008:administration & dosage / Q000378:metabolism*; D013997:Time Factors
D013004:Somatostatin; D009020:Morphine