+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Effects of naloxone and neonatal treatment with monosodium-L-glutamate on growth hormone and prolactin release induced by electrical stimulation of the medial-basal hypothalamus in rats

, : Effects of naloxone and neonatal treatment with monosodium-L-glutamate on growth hormone and prolactin release induced by electrical stimulation of the medial-basal hypothalamus in rats. Journal of Endocrinology 96(3): 427-432

The role of nerve cells of the arcuate nucleus and endogenous opioid peptides in the regulation of GH and prolactin secretion has been investigated. Electrical stimulation of the medial-basal hypothalamus (MBH) for 10 min raised plasma levels of both hormones in male rats anaesthetized with pentobarbitone sodium. Plasma hormone levels increased within 5 min after the termination of the stimulus, while no marked changes were found during stimulation. The GH response to the electrical stimulus was substantially reduced in rats with arcuate lesions induced by neonatal treatment with monosodium-L-glutamate (MSG). By contrast, the size of the prolactin response was not altered by MSG treatment. The opiate receptor antagonist naloxone (10 mg/kg, i.v.) failed to influence GH secretion induced by electrical stimulation in either control or MSG-treated animals. The post-stimulus rise of plasma prolactin levels was attenuated by naloxone in control rats, while the same dose of the drug was ineffective in rats which had been exposed to MSG. We conclude that endogenous opioids participate in the increase of prolactin release upon electrical stimulation of the MBH but are not involved in the GH secretory response. Arcuate neurones are important in the maintenance of the GH response to electrical stimulation. By contrast, lesioning of the arcuate nucleus failed to affect the prolactin secretory response elicited by MBH stimulation. However, prolactin release in MSG-treated rats appeared less susceptible to the inhibitory action of naloxone, suggesting a possible supersensitivity towards endogenous opioids.


PMID: 6833931

Other references

Pershukov, V.V.; Pataraia, S.A.; Batyraliev, T.A.; Niiazova-Karben, Z.A.; Sidorenko, B.A.; Preobrazhenskiĭ, D.V., 2005: Recommendations of the Working Group of European Society of Cardiology on diagnosis and treatment of pulmonary arterial hypertension. Kardiologiia 45(8): 84-91

Shilov M.P.; Mikhailova T.N.; Loktionov E.G., 1972: Water chestnut trapa natans in the vladimir district. Biologicheskie Nauki (Moscow) 15(3): 73-74

Niendorf, S.; Oksche, A.; Kisser, A.; Löhler, Jürgen.; Prinz, M.; Schorle, H.; Feller, S.; Lewitzky, M.; Horak, I.; Knobeloch, K-Peter., 2007: Essential role of ubiquitin-specific protease 8 for receptor tyrosine kinase stability and endocytic trafficking in vivo. Posttranslational modification by ubiquitin controls multiple cellular functions and is counteracted by the activities of deubiquitinating enzymes. UBPy (USP8) is a growth-regulated ubiquitin isopeptidase that interacts with the HRS-STAM complex....

Rozenski, J.; Crain, P.F.; McCloskey, J.A., 1998: The RNA Modification Database: 1999 update. The RNA Modification Database ( provides a comprehensive listing of naturally modified nucleosides in RNA. Each file includes: chemical structure; common name and symbol; type(s) of RNA in which found and corres...

Kovtyukhova, N.I.; Kelley, B.K.; Mallouk, T.E., 2004: Coaxially gated in-wire thin-film transistors made by template assembly. Nanowire field effect transistors were prepared by a wet chemical template replication method using anodic aluminum oxide membranes. The membrane pores were first lined with a thin SiO2 layer by the surface sol-gel method. Au, CdS (or CdSe), and A...

Brunette I.; Nelson L.R.; Bourne W.M., 1988: Corneal endothelial tolerance to cryoprotective agents. Investigative Ophthalmology & Visual Science 29(ABSTR ISSUE): 256

Cole, E.; Midtvedt, K.; Johnston, A.; Pattison, J.; O'Grady, C., 2002: Recommendations for the implementation of Neoral C(2) monitoring in clinical practice. Transplantation 73(9 Suppl): S19-S22

Heppner, C.; Becker, K.; Saeger, W.; Günther, R.W.; Allolio, B.; Krone, W.; Winkelmann, W., 1997: Occult eutopic Cushing's syndrome--failure of simultaneous bilateral petrosal sinus sampling to diagnose pituitary-dependent Cushing's syndrome. Simultaneous bilateral inferior petrosal sinus (IPS) sampling has been repeatedly proposed to be a highly specific approach for the diagnosis of Cushing's disease and 100% sensitivity in detecting autonomous pituitary ACTH secretion by an ade...

Dubowitz, L.; Mercuri, E.; Dubowitz, V., 1998: An optimality score for the neurologic examination of the term newborn. We describe the application of a revised version of the Dubowitz neurologic examination of the newborn in 224 low-risk, term newborn infants. The method has been updated by eliminating less useful items and including new items evaluating general m...

De-Castro, Piero, 2000: Praerhapydionina murgiana Crescenti, 1964 emendation and transfer to the genus Pseudorhipidionina De Castro, 1972 Foraminiferida, Upper Cenomanian, Italy. Praerhapydionina murgiana Crescenti, 1964, and Rhipidionina casertana De Castro, 1965, later designated as type species of Pseudorhipidionina De Castro, 1972, were erected for vertical partition-bearing peneropline foraminifera of upper Cenomania...