Wang_2001_Eur.J.Pharmacol_433_73

The fall in body temperature and inhibition of hypothalamic cholinesterase induced by rivastigmine a pseudo-reversible carbamate inhibitor were compared in male and female rats In males 1.5 mg/kg lowered body temperature by 1 degrees C and in females by 3.2 degrees C P<0.001 and inhibited cholinesterase by 65 and 74 respectively P<0.05 Pilocarpine 20 mg/kg decreased body temperature by 1.1 degrees C in males and 1.9 degrees C in females P<0.05 Orchidectomy but not ovariectomy abolished the sex difference in the hypothermic effect of pilocarpine and the enzyme inhibition induced by rivastigmine but not in its effect on body temperature Testosterone 10 mg/rat decreased the cholinesterase inhibition and the temperature reduction induced by rivastigmine in gonadectomised males and females but that induced by pilocarpine in males only In conclusion rivastigmine causes less inhibition of cholinesterase because testosterone may interfere with its entry into the brain Testosterone may further decrease the temperature-lowering effect of rivastigmine and acetylcholine receptor agonists in males by an action at a receptor level