Skip to main content
Journal cover image

Ontogenetic studies of tolerance development: effects of chronic morphine on the hypothalamic-pituitary-adrenal axis.

Publication ,  Journal Article
Little, PJ; Kuhn, CM
Published in: Psychopharmacology (Berl)
November 1995

Endogenous opiates are important regulators of the hypothalamic-pituitary-adrenal (HPA) axis in rats. Tolerance clearly develops to morphine-induced stimulation of the HPA axis in adult rats (Ignar and Kuhn 1990). The goal of the present study was to determine whether tolerance to morphine-induced stimulation of the HPA axis developed in neonatal and weanling rats treated chronically with morphine. Rats were injected with morphine or saline between days 4-8 postnatal (pups) or days 21-25 (weanlings) and tolerance assessed by determining dose-response curves for ACTH and corticosterone secretion following an acute morphine challenge. Weanlings displayed marked tolerance to the stimulation of ACTH and corticosterone secretion by morphine. Tolerance was also observed in pups to morphine-stimulated ACTH and corticosterone release. These findings suggest that the relative adaptability of the HPA axis to chronic morphine in neonatal and weanling rats is similar.

Duke Scholars

Published In

Psychopharmacology (Berl)

DOI

ISSN

0033-3158

Publication Date

November 1995

Volume

122

Issue

1

Start / End Page

78 / 84

Location

Germany

Related Subject Headings

  • Rats, Sprague-Dawley
  • Rats
  • Psychiatry
  • Pituitary-Adrenal System
  • Morphine Dependence
  • Morphine
  • Male
  • Hypothalamo-Hypophyseal System
  • Female
  • Corticosterone
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Little, P. J., & Kuhn, C. M. (1995). Ontogenetic studies of tolerance development: effects of chronic morphine on the hypothalamic-pituitary-adrenal axis. Psychopharmacology (Berl), 122(1), 78–84. https://doi.org/10.1007/BF02246445
Little, P. J., and C. M. Kuhn. “Ontogenetic studies of tolerance development: effects of chronic morphine on the hypothalamic-pituitary-adrenal axis.Psychopharmacology (Berl) 122, no. 1 (November 1995): 78–84. https://doi.org/10.1007/BF02246445.
Little, P. J., and C. M. Kuhn. “Ontogenetic studies of tolerance development: effects of chronic morphine on the hypothalamic-pituitary-adrenal axis.Psychopharmacology (Berl), vol. 122, no. 1, Nov. 1995, pp. 78–84. Pubmed, doi:10.1007/BF02246445.
Journal cover image

Published In

Psychopharmacology (Berl)

DOI

ISSN

0033-3158

Publication Date

November 1995

Volume

122

Issue

1

Start / End Page

78 / 84

Location

Germany

Related Subject Headings

  • Rats, Sprague-Dawley
  • Rats
  • Psychiatry
  • Pituitary-Adrenal System
  • Morphine Dependence
  • Morphine
  • Male
  • Hypothalamo-Hypophyseal System
  • Female
  • Corticosterone