Effect of chronic and acute stress on ectonucleotidase activities in spinal cord.
We have previously observed that, while acute stress induces analgesia, chronic stress causes a hyperalgesic response in male rats. No effect was observed in females. There is increasing evidence that both ATP and adenosine can modulate pain. Extracellular ATP and ADP are hydrolyzed by an apyrase in synaptosomes from the peripheral and central nervous systems. In the present study, we investigated the effect of chronic and acute stress on ATPase-ADPase and 5'-nucleotidase activities in spinal cord of male and female rats. Adult male and female Wistar rats were submitted to 1 h restraint stress/day for 1 day (acute) or 40 days (chronic) and were sacrificed 24 h later. ATPase-ADPase activities were assayed in the synaptosomal fraction obtained from the spinal cord of control and stressed animals. ADP hydrolysis was decreased 25% in chronically stressed males, while no change was observed on ATPase activity. There was an increase in the 5'-nucleotidase activity in the same group. No effect on ADPase, ATPase or on 5'-nucleotidase activity was observed in females with chronic stress, or after acute stress neither in males or females. Chronic stress reduced ADP hydrolysis and increased 5'-nucleotidase activity in the spinal cord in male rats.
Torres
Iraci Lucena S
IL
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, 90035-003, Porto Alegre, RS, Brazil. torresf@zaz.com.br
Buffon
Andréia
A
Silveira
Patricia Pellufo
PP
Duarte
Marcelo Z D
MZ
Bassani
Marcio Garcia
MG
Oliveira
Silvana S
SS
Battastini
Ana Maria O
AM
Sarkis
João J F
JJ
Dalmaz
Carla
C
Ferreira
Maria Beatriz C
MB
D015720:5'-Nucleotidase / Q000378:metabolism; D000208:Acute Disease; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001081:Apyrase / Q000378:metabolism; D002908:Chronic Disease; D005260:Female; D008297:Male; D009708:Nucleotidases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012149:Restraint, Physical; D012727:Sex Characteristics; D013116:Spinal Cord / Q000201:enzymology*; D013315:Stress, Psychological / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology; D013574:Synaptosomes / Q000378:metabolism
D009708:Nucleotidases; D015720:5'-Nucleotidase; D000251:Adenosine Triphosphatases; D001081:Apyrase