Effects of restraint stress on responsiveness of atria and vas deferens in Sprague–Dawley rats

Abstract

1 The effects of stress in rats were evaluated by measuring changes in body weight and in responsiveness to noradrenaline (NA) in the isolated vas deferens and atria after the animals had been exposed to restraint or restraint and isolation. 2 Animals which were subjected to restraint alone (1 h day-1 for 3, 7 or 28 days) had a significantly reduced rate of body weight gain. This effect was not potentiated by the additional stress of isolation. 3 Restraint alone did not produce significant changes in the responsiveness of the vas deferens to NA. However, adding isolation to restraint, as an additional stress, produced a further leftward shift of the NA dose-response curve for the vas deferens, so that there was a significant increase in sensitivity compared with control. 4 There was a significant rightward shift in the NA dose-response curves or reduction in sensitivity in the atria from animals which had been restrained for 7 or 28 days. Isolation did not produce a further rightward shift in the NA dose-response curve. 5 The results from this study indicate that the stress associated with repeated restraint reduces the rate of weight gain and reduces the responsiveness of the atria to NA. The responsiveness of the vas deferens to NA was increased by stress, but the combined effect of isolation and restraint was required to produce a significant effect. The differences in the effects of stress on these tissues could be associated with differences in presynaptic receptor populations.

Emerging Evidence for a Central Epinephrine-Innervated α1-Adrenergic System that Regulates Behavioral Activation and is Impaired in Depression

“…Similar desensitizing effects of stress on a 1 -receptors were reported in the peripheral nervous system, where chronic stress reduced the a 1 -stimulated contraction of the isolated vas deferens (Singh et al, 2001) and downregulated the density of a 1 -binding sites in the heart (Torda et al, 1985). Furthermore, endotoxin (lipopolysaccharide, LPS) and septic shock markedly desensitized and downregulated vascular a 1 -receptors (Suba et al, 1992;Wakabayashi et al, 1989).…”

The effects on heart rate and temperature of mice and vas deferens responses to noradrenaline when their cage mates are subjected to daily restraint stress

“…It has previously been shown that repeated stress causes the vas deferens to become hypersensitive to NAd (Singh et al 2001, Einstein et al 2004. In this study, it was found that the vas deferens from the restraint-associated mice had a significantly higher responsiveness to NAd than the vas deferens isolated from the handlingassociated mice.…”

“…Prolonged sympathetic activity due to chronic stress can cause lasting changes in the physiology of the animal. One change that has been observed following chronic stress is hypersensitivity of the vas deferens to NAd in both mice and rats (Singh et al 2001, Einstein et al 2004).…”

Functional alterations of mesenteric vascular bed, vas deferens and intestinal tracts in a rat hindlimb unloading model of microgravity

“…As far as gastrointestinal function, experiments carried out on gastric myoelectric activity in rhesus monkeys during flight, showed contrasting alterations between the subjects studied (Badakva & Miller, 2000). The vas deferens seems to be an organ that is highly sensitive to extreme conditions, such as microgravity, that can involve also a stressful component, since the responsiveness of vas deferens to NA has been shown to be increased by stress (Singh, Einstein & Lavidis, 2001).…”