Interactions among aging, gender, and gonadectomy effects upon morphine antinociception in rats

Islam, Anita; Cooper, Madeline L.; Bodnar, Richard J.

doi:10.1016/0031-9384(93)90042-e

Cited by 112 publications

(58 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the only other study in which T was administered to adult GDX males -30 min before testing -T did not restore morphine sensitivity (Chatterjee et al, 1982). Previous studies in which only gonadectomy was performed in adult male rats reported that sensitivity to morphine either increased (Ali et al, 1995;Chatterjee et al, 1982;Terner et al, 2002) or did not change (Kepler et al, 1989;Candido et al, 1992;Islam et al, 1993;Cicero et al, 1996Cicero et al, , 2002Krzanowska and Bodnar, 1999) relative to controls. Some of these studies varied considerably from the present study in their methodology (e.g.…”

Section: Effects Of Gonadal Steroid Manipulations In Malesmentioning

confidence: 77%

“…The activational role of gonadal steroids has been examined by many laboratories, but with inconsistent results. For example, gonadectomy of adult male rats or mice has been shown to increase (Chatterjee et al, 1982;Ali et al, 1995), decrease (Rao and Saifi, 1985;, or not affect (Kepler et al, 1989(Kepler et al, , 1991Candido et al, 1992;Islam et al, 1993;Cicero et al, 1996Cicero et al, , 2002Krzanowska and Bodnar, 1999) opioid antinociception. Gonadectomy in adult female rats also has been shown to increase (Kepler et al, 1989;Ali et al, 1995;Krzanowska and Bodnar, 1999;Terner et al, 2002), decrease (Banerjee et al, 1983), or not affect (Kepler et al, 1991;Cicero et al, 1996Cicero et al, , 2002Terner et al, 2002) opioid antinociception.…”

Section: Introductionmentioning

confidence: 99%

“…Gonadectomy in adult female rats also has been shown to increase (Kepler et al, 1989;Ali et al, 1995;Krzanowska and Bodnar, 1999;Terner et al, 2002), decrease (Banerjee et al, 1983), or not affect (Kepler et al, 1991;Cicero et al, 1996Cicero et al, , 2002Terner et al, 2002) opioid antinociception. The effect of adult gonadectomy on opioid antinociception has been shown to depend on subject age and opioid dose (Islam et al, 1993), as well as rodent genotype and opioid efficacy .…”

Section: Introductionmentioning

confidence: 99%

“…For example, some researchers tested only one dose of morphine (Rao and Saifi, 1985;Ratka and Simpkins, 1991;Ali et al, 1995), whereas others tested a range of doses (e.g. Chatterjee et al, 1982;Banerjee et al, 1983;Nomikos et al, 1987;Kepler et al, 1989;Candido et al, 1992;Islam et al, 1993;Cicero et al, 1996;Krzanowska and Bodnar, 1999). Testing multiple doses of drug is preferable as it provides important information about how gonadal steroids affect drug potency and efficacy, which cannot be deduced from single-dose studies.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Gonadal steroid hormone modulation of nociception, morphine antinociception and reproductive indices in male and female rats

Stoffel

Ulibarri

Craft

2003

Pain

167

137

View full text Add to dashboard Cite

The purpose of this study was to examine how gonadal steroid hormones modulate basal nociception and morphine antinociception relative to regulating reproduction in the adult rat. Male and female Sprague-Dawley rats were either gonadectomized (GDX) or sham-gonadectomized (sham); GDX males were implanted subcutaneously with capsules containing testosterone (T), estradiol (E2), dihydrotestosterone (DHT), E2 and DHT, or nothing (0). GDX females received E2, T, or empty (0) capsules immediately after surgery, and vehicle or progesterone (P4) injections at 4-day intervals. Basal nociception and morphine antinociception were tested 28 days after surgery on 50°C and 54°C hotplate tests, and reproductive behavior and physiology were assessed shortly thereafter. There were no significant differences in baseline hotplate latencies among the male treatment groups, but morphine was significantly more potent in sham and GDX + T males than in GDX + 0 males. The ability of T to increase morphine's potency was approximated by its major metabolites E2 and DHT, given together but not alone. Baseline hotplate latencies were higher in sham females tested during diestrus than in those tested during estrus. Morphine was significantly more potent in sham females tested during proestrus and diestrus than in those tested during estrus. Baseline hotplate latencies were significantly higher, and morphine was significantly less potent in GDX + E2, GDX + E2/P4 and GDX + T females than in GDX + 0 females. All group differences in basal nociception and morphine antinociception observed on the 50°C hotplate test were smaller and generally nonsignificant on the 54°C hotplate test. Steroid manipulations produced the expected changes in reproductive behaviors and steroid-sensitive organs. These results demonstrate that in adult rats, gonadal steroid manipulations that are physiologically relevant, modulate (1) basal nociception in females but not males, and (2) morphine's antinociceptive potency in both males and females.

show abstract

Section: Effects Of Gonadal Steroid Manipulations In Malesmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Gonadal steroid hormone modulation of nociception, morphine antinociception and reproductive indices in male and female rats

Stoffel

Ulibarri

Craft

2003

Pain

167

137

View full text Add to dashboard Cite

show abstract

“…Some evidence exists for an estrus cycle-dependent modulation of opioid antinociception (21)(22)(23), as well as for an interaction between sex hormones and opioid antinociceptive potency (14,(24)(25)(26). Moreover, the removal of sex steroids by gonadectomy affects the antinociceptive activity of morphine in some experimental paradigms (16,(27)(28)(29).…”

mentioning

confidence: 99%

Sex and Estrus Cycle Differences in the Modulatory Effects of Morphine on Seizure Susceptibility in Mice

et al. 2004

View full text Add to dashboard Cite

Summary:Purpose: To evaluate the effects of sex and estrus cycle on biphasic anticonvulsant and proconvulsant modulation of seizure threshold by morphine.Methods: The threshold for the clonic seizures (CST) induced by acute intravenous administration of γ -aminobutyric acid (GABA)-antagonist pentylenetetrazole (PTZ) was assessed in male and female mice. Estrus cycle was assessed by vaginal smears. The effect of removing circulating sex hormones was assessed by gonadectomy.Results: At baseline, diestrus females had a higher CST compared with males and estrus females. Morphine at lower doses (0.5-3 mg/kg) had a significant anticonvulsant effect in males and estrus females compared with that in vehicle-treated controls, whereas female mice in diestrus phase showed a relative subsensitivity to this effect. Morphine at higher doses (30 and 60 mg/kg) significantly decreased CST in males and diestrus females, with less relative effect in estrus mice. In both phases, morphine exerted stronger effects in males compared with females. Ovariectomy brought the baseline CST to the male level and resulted in significant expression of both phases of morphine effect but did not abolish the sex difference in responsiveness to morphine.Conclusions: The biphasic modulation of seizure threshold is subject to both constitutive sex differences in sensitivity to morphine and hormonal fluctuations during the estrus cycle.

show abstract

Pharmacokinetic aspects of naloxone‐precipitated morphine withdrawal in male and female prepubertal mice

Diaz

Hermida

Joannas

et al. 2007

Biopharm & Drug Disp

View full text Add to dashboard Cite

It has been shown that the expression of the morphine (MOR) withdrawal syndrome precipitated by naloxone (NAL) is more intense in male mice than in females, but the reasons for this phenomenon remain uncertain. The purpose of the present study was to evaluate whether this sexual dimorphism might be due to differences in MOR and/or NAL plasma levels after a chronic treatment with MOR. Prepubertal Swiss male and female mice were rendered dependent by intraperitoneal (i.p.) injection of MOR (2 mg/kg), twice daily for 9 days. On day 10 dependent mice received NAL (6 mg/kg, i.p.) 60 min after MOR injection. Blood samples were taken at different times in order to determine MOR and NAL plasma levels by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC), respectively. Pharmacokinetic analysis showed no differences between male and female mice either for MOR or for NAL. In conclusion, although males and females respond differentially to NAL-precipitated withdrawal, this dimorphic behavior would not be influenced by a pharmacokinetic factor.

show abstract

Interactions among aging, gender, and gonadectomy effects upon morphine antinociception in rats

Cited by 112 publications

References 53 publications

Gonadal steroid hormone modulation of nociception, morphine antinociception and reproductive indices in male and female rats

Gonadal steroid hormone modulation of nociception, morphine antinociception and reproductive indices in male and female rats

Sex and Estrus Cycle Differences in the Modulatory Effects of Morphine on Seizure Susceptibility in Mice

Pharmacokinetic aspects of naloxone‐precipitated morphine withdrawal in male and female prepubertal mice

Contact Info

Product

Resources

About