... increased GH release when given individually. Combinations of clonidine, 6 and 30 µg/kg, and the serotonin agonist quipazine 160 µg/kg had an additive effect on GH release. Almost all combinations of morphine, 40 and 200 µg/kg, with clonidine and quipazine stimulated GH release, but this release was less...

... if nicotine, morphine and the serotonin 1A (5-HT 1A ) agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) utilize a common synaptic pathway to release prolactin and, if so, to establish the serial order of the receptors involved. We also sought to determine whether the pathway under investigation leads...

... and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements. Opioid binding sites Chondrocytes Growth plate Autoradiography β-Endorphin Naloxone Morphine Original Paper...

.... In the present study, we further evaluated the apparent universality of alterations in opiate-mediated function during the LH surge by investigating the effects of morphine sulfate (MS) on prolactin (PRL) secretion during both the estradiol benzoate (EB) and the EB + P4-induced LH surges. All doses of MS tested...

..., caused an increase in plasma concentrations of LH and FSH, and antagonized the LH suppressory effect of morphine (10 mg/kg) administration. Despite this, naltrexone treatment was ineffective in preventing the inhibitory effect of chronic restraint stress on circulating LH and FSH. Chronic restraint also...

...Meharvan Singh; James W. Simpkins; Meri P. Layden; Teresa M. Romano; William J. Millard Earlier studies from our laboratory have shown that treatments with gonadal steroids which cause a surge of luteinizing hormone (LH) blunt the effects of morphine on LH secretion, locomotor activity, nociception...

... rats morphine (3 mg/kg s.c), and clonidine (31 µg/kg i.p.) induced a significant increase in plasma GH levels. The pretreatement with the alpha 2 antagonist yohimbine (1 and 3 mg/kg) effectively inhibited the GH releasing effect or morphine and clonidine. CH-38083 at the dose of 1 mg/kg did...

...Phyllis E. Mann; Craig H. Kinsley; Robert S. Bridges Central or systemic administration of morphine disrupts maternal behavior in steroid-primed, pup-induced virgin and lactating rats. Morphine, the prototypical µ agonist, also interacts with different opioid receptor subtypes. The present study...

...-release morphine (75 mg) or placebo pellet. Morphine decreased TSH by 44% at 1 h and by 83% at 3 h, and TSH remained significantly depressed by 38% through 48 h. Thyroxine (T 4 ) levels were significantly reduced from 12 to 24 h after morphine, but triiodothyronine (T 3 ) levels were not affected. When...

...Cynthia L. Williams; Masugi Nishihara; Jean-Christophe Thalabard; Kevin T. O’Byrne; Peter M. Grosser; Julane Hotchkiss; Ernst Knobil The effects of morphine on the frequency and duration of the characteristic bursts or ‘volleys’ of multiunit electrical activity (MUA) associated with pulsatile...

...Dean A. Van Vugt; Natalia Baby; Martin Stewart; Robert L. Reid We previously observed that morphine stimulated luteinizing hormone (LH) secretion from ovariectomized rats when administered intravenously at a dose of 10 mg/kg body weight. The objectives of the present study were to determine: (1...

... amplitude and frequency. This stimulatory action of naloxone was prevented by simultaneous infusion with morphine, and was not associated with any change in in vivo pituitary responsiveness to LHRH, indicating that this was an action exerted through centrally located EOP receptors. Naloxone also increased...

...John T. Clark; Steven M. Gabriel; James W. Simpkins; Satya P. Kalra; Pushpa S. Kalra The effects of sustained delivery of morphine and/or testosterone (T) on male rat copulatory behavior, penile reflexes and dopaminergic metabolism in selected brain regions were examined. Castration was followed...

...Mauro Bianchi; Antonio Marini; Paola Sacerdote; Ennio Cocco; Anna Brini; Alberto E. Panerai Normal or pregnant rats were treated orally for 21 days or throughout pregnancy with water or increasing doses of morphine and killed on days 7, 14, and 21 of pregnancy and 1 day post partum. At these time...

...Shuso Suemaru; Mary F. Dallman; Daniel N. Darlington; Caren S. Cascio; Jeanette Shinsako The role of α-adrenergic mechanism in the acute effects of morphine in the hypothalamo-pituitary-adrenocortical (HPA) and cardiovascular (CV) systems, and the interrelationship between the HPA and CV responses...

...D. Thanh Kiem; Béla Kanyicska; Ervin Stark; Márton I.K. Fekete Diurnal variations of the effectivity of β-endorphin (β-End), dynorphin (DYN), Met-enkephalin (Met-Enk), D-Met 2 -Pro 5 -enkephalinamide (D-Met-Pro-Enk) and morphine to induce prolactin (PRL) and adrenocorticotropin (ACTH...

...I. Caroline McMillen; Jan M. Deayton This study investigated the effects of intrafetal morphine or naloxone administration on fetal and maternal plasma prolactin concentrations in the sheep during late pregnancy (117–143 days gestation). After intravenous morphine (3 mg/kg) there was a significant...

...Julia C. Buckingham; Teresa A. Cooper The influences of morphine and naloxone on hypothalamo-pituitary-adrenocortical (HPA) function were studied in the rat to investigate further the role of opioidergic mechanisms in the control of the secretion of corticotrophin and its hypothalamic releasing...

... with 3 H-NA and then subjected to electric field stimulation. Morphine (10 µM) significantly reduced the amount of NA released in response to electrical stimulation, an effect that was completely prevented by simultaneous exposure to equimolar naloxone. This inhibitory action of morphine...

..., in anesthetized animals that had been hypophysectomized acutely, portal plasma concentrations of ir-β-END were still 5 times those in systemic plasma, indicative of hypothalamic secretion of the peptide. The administration of morphine sulfate (3 mg/kg, i.v.) resulted in a decrease of ir-β-END concentrations from...