ISSN:
1432-2072
Keywords:
Physostigmine
;
Antinociception
;
Dexamethasone
;
Endogenous opiates
;
Adrenalectomy
;
Tail flick
;
Pituitary
;
adrenal axis
;
Muscarinic receptors
;
Cholinesterase inhibitors
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The tail-flick procedure was used to study the antinociceptive effects of physostigmine in adrenalectomized and sham-operated rats. At 5 days after surgery, they were tested 30 min after either 0.32 or 0.45 mg/kg IP physostigmine. Adrenalectomized animals showed significantly greater elevation of TF scores from predrug latencies than the sham controls at both doses of physostigmine. Following 3 days of dexamethasone replacement therapy on days 18, 19, and 20 post-surgery the antinociceptive effects of physostigmine were uniformly attenuated across doses or surgical groups. On the other hand, animals receiving saline injection instead of dexamethasone did not manifest any reduction of the physostigmine antinociceptive effect. The potentiation by adrenalectomy and the reduction following dexamethasone of the antinociceptive effects of physostigmine suggest that these effects may be mediated through hypothalamic-pituitary-adrenal mechanisms and are consistent with β-endorphin-induced sensitization of opiate or cholinergic receptors.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00555226
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