Opioid systems and the newborn

Marsh, D F; Hatch, D. J.; Fitzgerald, Maria

doi:10.1093/bja/79.6.787

Cited by 72 publications

(36 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Little is known about sensitivity to systemic morphine and the development of morphine tolerance in adolescents. The opioid system changes throughout early postnatal development in rats (reviewed in Marsh et al, 1997) and these changes result in different sensitivities to opioid-induced antinociception and tolerance in different age rats (Fanselow and Cramer, 1988;Windh et al, 1995;Thornton et al, 1997;Zhu and Barr, 2003).…”

Section: Introductionmentioning

confidence: 99%

Behavioral and Electrophysiological Evidence for Opioid Tolerance in Adolescent Rats

Ingram

Fossum

Morgan

2006

Neuropsychopharmacol

View full text Add to dashboard Cite

Morphine and other opiates are successful treatments for pain, but their usefulness is limited by the development of tolerance. Given that recent studies have observed differential sensitivity to drugs of abuse in adolescents, the aim of this study was to assess antinociceptive tolerance to morphine in adolescent rats using both behavioral and cellular measures. Early (28-35 days postnatal) and late (50-59 days) adolescent and adult (73-75 days) male rats were injected with morphine (5 mg/kg, s.c.) or saline twice a day for two consecutive days. On Day 3, tolerance to morphine was evident in morphine-pretreated rats when tested on the hot plate test. Although baseline latencies for the early compared to late adolescent rats were faster, the magnitude of the shift in ED 50 for morphine was similar for the two adolescent groups. However, the shift in ED 50 tended to be greater in adolescent compared to adult rats. Subsequent to behavioral testing, whole cell patch-clamp recordings were made from ventrolateral PAG neurons. The opioid agonist, met-enkephalin (ME), activated similar outward currents in PAG neurons of early and late adolescent rats. However, reversal potentials of ME-induced currents were shifted to more hyperpolarized potentials in cells from morphine-pretreated rats. In addition, ME induced larger currents in morphine-pretreated rats with faster hot plate latencies compared to the mean (more tolerant) than in rats with slower latencies. These results indicate that repeated intermittent administration of morphine produces tolerance in adolescent rats that is associated with novel changes in opioid-sensitive ventrolateral PAG neurons.

show abstract

Section: Introductionmentioning

confidence: 99%

Behavioral and Electrophysiological Evidence for Opioid Tolerance in Adolescent Rats

Ingram

Fossum

Morgan

2006

Neuropsychopharmacol

View full text Add to dashboard Cite

show abstract

“…11,12 There is increasing evidence [13][14][15][16][17] to suggest that these repeated invasive procedures have long-term consequences. Given the frequency of painful procedures, the potential negative consequences of experiencing repeated painful procedures, and the potential risks of opiate analgesics for frequent procedural pain, 18 it would seem that nonpharmacological interventions should be tested to control for procedural pain. 19 Pain decreases state regulation, 20 and KC has been shown to improve state regulation.…”

mentioning

confidence: 99%

Kangaroo Care Is Effective in Diminishing Pain Response in Preterm Neonates

Johnston¹,

Stevens²,

Pinelli³

et al. 2003

Arch Pediatr Adolesc Med

263

177

View full text Add to dashboard Cite

For preterm neonates who are 32 weeks' postmenstrual age or older, KC seems to effectively decrease pain from heel lancing. Further study is needed to determine if younger neonates or those requiring assistance in breathing, or older infants or toddlers, would benefit from KC, or if it would remain effective over several procedures. Given its effectiveness, and that parents of neonates in critical care units want to participate more in comforting their children, KC is a potentially beneficial strategy for promoting family health.

show abstract

“…On the one hand, opiate dependence can be established in fetuses or infant rat pups if the dams are exposed to opiates during their pregnancy or the pups are treated directly with opiates Barr 1995, 2000;Windh et al 1995;Barr et al 1998). On the other hand, the neonatal CNS is both structurally and functionally different from that of the adult, and significant changes in opioid actions occur both prenatally and postnatally (Barr 1992(Barr , 1993Fitzgerald 1995;Marsh et al 1997;Fitzgerald and Jennings 1999). More importantly, the NMDA receptor, which is believed to play a crucial role in the establishment of opiate dependence, undergoes qualitative and quantitative changes during development (Kalb et al 1992;Hori and Kanda 1994;Kalb and Fox 1997).…”

mentioning

confidence: 99%

Attenuation of Acute Morphine Withdrawal in the Neonatal Rat by the Competitive NMDA Receptor Antagonist LY235959

Jones

Zhu

Jenab

et al. 2002

Neuropsychopharmacology

View full text Add to dashboard Cite

The present study examined the ability of LY235959, a competitive N-methyl-D-aspartate (NMDA) receptor antagonist, to attenuate behaviors and c-fos mRNA expression associated with acute morphine withdrawal in the infant rat. Rat pups were given a single dose of morphine (10.0 mg/kg, s.c.) or saline. Two hours later, pups were removed from the dam and injected with either LY235959 (10.0 mg/kg, s.c.) In humans, exposure to opiates for either medical or nonmedical reasons leads to dramatic behavioral and neural changes resulting in physical dependence (Trujillo and Akil 1991b). Although physical dependence is classically thought to develop after chronic exposure to opiates (chronic opiate dependence), the adaptational changes underlying physical dependence begin with the first exposure to an opiate (Heishman et al. 1989a,b;Kirby et al. 1990). Thus, acute opiate withdrawal refers to the withdrawal syndrome precipitated by administration of an opioid antagonist after either a single dose or a short-term infusion of opioid agonist (Martin and Eades 1964;Bickel et al. 1988).Despite decades of research, our understanding of the mechanisms underlying opiate physical dependence and withdrawal is still very limited (Mayer et al. 1999;Trujillo 1999) and multiple mechanisms may operate in these processes (Thorat et al. 1994). There is increasing evidence indicating that N-methyl-D-aspartate (NMDA) receptor antagonists inhibit the development of mu receptor mediated opiate dependence in the adult NO . 3 rodent, and that the NMDA receptor and its second messenger systems play pivotal roles in opiate tolerance, dependence and withdrawal (Trujillo and Akil 1991a;Inturrisi 1997;Mao 1999;Mayer et al. 1999).It is not known whether these mechanisms in adults apply to infants. On the one hand, opiate dependence can be established in fetuses or infant rat pups if the dams are exposed to opiates during their pregnancy or the pups are treated directly with opiates Barr 1995, 2000;Windh et al. 1995;Barr et al. 1998). On the other hand, the neonatal CNS is both structurally and functionally different from that of the adult, and significant changes in opioid actions occur both prenatally and postnatally (Barr 1992(Barr , 1993Fitzgerald 1995;Marsh et al. 1997;Fitzgerald and Jennings 1999). More importantly, the NMDA receptor, which is believed to play a crucial role in the establishment of opiate dependence, undergoes qualitative and quantitative changes during development (Kalb et al. 1992;Hori and Kanda 1994;Kalb and Fox 1997). These include significant developmental alterations both in the density of the receptor (Tremblay et al. 1988;Morin et al. 1989;Represa et al. 1989), the sensitivity of the receptor complex to magnesium Bowe and Nadler 1990;Morrisett et al. 1990), and the rise and decay times of the NMDA receptor-mediated excitatory post-synaptic currents (EPSCs) (Akaike and Rhee 1997;Bardoni et al. 1998). Recently, due to the advancement in cloning technology and gene knockout technology, the molecular structure of the...

show abstract

Opioid systems and the newborn

Cited by 72 publications

References 64 publications

Behavioral and Electrophysiological Evidence for Opioid Tolerance in Adolescent Rats

Behavioral and Electrophysiological Evidence for Opioid Tolerance in Adolescent Rats

Kangaroo Care Is Effective in Diminishing Pain Response in Preterm Neonates

Attenuation of Acute Morphine Withdrawal in the Neonatal Rat by the Competitive NMDA Receptor Antagonist LY235959

Contact Info

Product

Resources

About