We tested whether that peripheral
inflammation induces changes in the spinal dorsal horn
ATPase activity. Adult Sprague-Dawley rats were anesthetized (
thiobarbital), the left hind paw (
inflammation group; n = 15) was immersed in water at 60 degrees C for 60s, which induced a local
inflammation. A control group (n = 12) was tested with water at room temperature. After 60 min of peripheral
inflammation left (LDH) or right lumbar dorsal horn (RDH) were processed for total, Na/K, Na and remanent
ATPase activities (nM P(i) (mgprotein)(-1) min(-1)). In control animals isoenzymatic activities were: Na (31.2%); Na/K (20.6%) and remanent (48.2%) from total
ATPase activity. No LDH-RDH asymmetry was found. The
inflammation group presented an ipsilateral increase of total
ATPase activity in
LDH (X+/-S.E.M.; 4798.9+/-601) over the RDH (3982.2+/-451; Delta+817; P<0.05). This is due to an increase in
Na ATPase activity (1609.3+/-297) over RDH (1164.2+/-166; Delta+445; P<0.05).
ATPase activities were increased in LDH from inflamed over the control group as follows: total (4798.9+/-601; Delta+840; P<0.05), Na/K (1298.1+/-301; Delta+483; P<0.05) and Na (1609.3+/-297; Delta+373; P<0.05). These increased
ATPase activities, induced in a short time, can be considered a functional marker of nociceptive neuronal activity.