Torres Iraci Lucena S, Buffon Andréia, Silveira Patricia Pellufo, Duarte Marcelo Z D, Bassani Marcio Garcia, Oliveira Silvana S, Battastini Ana Maria O, Sarkis João J F, Dalmaz Carla, Ferreira Maria Beatriz C
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, 90035-003, Porto Alegre, RS, Brazil.
Physiol Behav. 2002;75(1-2):1-5. doi: 10.1016/s0031-9384(01)00605-9.
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.
我们之前观察到，虽然急性应激会诱导镇痛，但慢性应激会在雄性大鼠中引起痛觉过敏反应。在雌性大鼠中未观察到这种影响。越来越多的证据表明，三磷酸腺苷（ATP）和腺苷都可以调节疼痛。外周和中枢神经系统突触体中的一种外切核苷酸酶可将细胞外ATP和二磷酸腺苷（ADP）水解。在本研究中，我们调查了慢性和急性应激对雄性和雌性大鼠脊髓中ATP酶-ADP酶和5'-核苷酸酶活性的影响。成年雄性和雌性Wistar大鼠每天接受1小时的束缚应激，持续1天（急性）或40天（慢性），并在24小时后处死。在从对照和应激动物的脊髓中获得的突触突触小突触体部分中测定ATP酶-ADP酶活性。慢性应激的雄性大鼠中ADP水解降低了25%，而ATP酶活性未观察到变化。同一组中5'-核苷酸酶活性增加。慢性应激的雌性大鼠或急性应激后，无论雄性还是雌性，均未观察到对ADP酶、ATP酶或5'-核苷酸酶活性的影响。慢性应激降低了雄性大鼠脊髓中的ADP水解并增加了5'-核苷酸酶活性。
