The effect of N-nitro-L-arginine methyl ester on morphine-induced changes in the plasma corticosterone and testosterone levels in mice

Abstract

Effects of the nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg i.p.), on morphine-induced changes in the plasma corticosterone and testosterone levels were studied in male mice. Acute morphine administration (15 and 30 mg/kg i.p.) enhanced the corticosterone level after 1 and 2 hr (at a dose of 30 mg/kg only). A 4-day treatment with increasing doses of morphine, from 15 to 50 mg/kg i.p., increased the plasma corticosterone concentration at 2 hr after the last injection. Single administration of L-NAME (30 mg/kg i.p.) had no effect on the corticosterone level, whereas its repeated injections (30 mg/kg i.p., twice a day for four days) elevated the hormone concentration at 2 hr after the last dose. Pretreatment of mice with L-NAME enhanced the stimulatory effects of both acute and repeated morphine administration on the corticosterone level. D-NAME (30 mg/kg i.p.), an inactive form of the nitric oxide synthase inhibitor, had no effect on the morphine-induced changes in the corticosterone level. Acute morphine administration had no effect on the plasma testosterone level after 1 or 2 hr, whereas repeated drug injections decreased the hormone concentration after 2 hr. Single or repeated L-NAME administration did not influence the testosterone level in either control or morphine-treated animals. The above results indicate that inhibition of nitric oxide synthase enhances the stimulatory effect of morphine on corticosterone secretion, but does not influence the inhibitory effect of repeated morphine on the plasma testosterone concentration in mice.

Socially induced morphine pseudosensitization in adolescent mice

“…An increase in aggressive behaviors is unlikely during morphine intoxication, since opioids have been demonstrated to decrease plasma testosterone levels in both adult humans (Abs et al, 2000, Rasheed and Tareen, 1995) and rodents (Budziszewska et al, 1999, Gabriel et al, 1986). Like adults, morphine was also demonstrated to decrease plasma testosterone levels in adolescent rats (Yilmaz et al, 1999, Cicero et al, 1989).…”

Interactions between morphine and nitric oxide in various organs

“…Budziszewska et al [141] found that single or repeated administrations of morphine increased plasma corticosterone in mice, and repeated, but not single, administration of L-NAME elevated the hormone level; pretreatment with L-NAME enhanced the stimulatory effects of morphine administration. On the other hand, repeated morphine injections decreased the plasma testosterone concentration, and pretreatment with L-NAME did not affect the hormone level in the morphine-treated mice.…”

Οπιοειδές Σύστημα Και Καρκίνος Του Προστάτη

“…µπορεί να οδηγήσει σε κυτταρικό θάνατο, ενώ παράλληλα έχει βρεθεί ότι η παραγωγή της από τα καρκινικά κύτταρα ενισχύει την αγγειογένεση και το µεταστατικό δυναµικό ενός όγκου (Adams et al 1996;Budziszewska et al 1999;Bhat et al 1998). Επίδραση των οπιοειδών στη παραγωγή της ΝΟ .…”

“…αναστέλλουν τη δράση της µορφίνης στην στεροειδογέννεση(Adams et al 1996) ενώ αναστολείς της συνθετάσης της ΝΟ . (NOS) αναστρέφουν τη δράση των οπιοειδών ανταγωνιστών(Budziszewska et al 1999) µέσω διαφορετικών µηχανισµών. Επιπλέον, η ΝΟ .…”