∂-Opioid Receptors and the Secretion of Growth Hormone in Man: Effect of Opioid ∂-Receptor Agonist Deltorphin on GH Responses to GH-Releasing Hormone and Insulin-Induced Hypoglycemia

1992 ◽  
Vol 56 (6) ◽  
pp. 907-912 ◽  
Author(s):  
Ettore Ciro degli Uberti ◽  
Severn Salvadori ◽  
Giorgio Trasforini ◽  
Angelo Margutti ◽  
Maria Rosaria Ambrosio ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Releasing Hormone ◽  
Opioid Receptor Agonist

Properties of TAN-67, a nonpeptide δ-opioid receptor agonist, at cloned human δ-and μ-opioid receptors

1995 ◽  
Vol 291 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Richard J. Knapp ◽  
Robert Landsman ◽  
Sue Waite ◽  
Ewa Malatynska ◽  
Eva Varga ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Opioid Receptor Agonist ◽  
Δ Opioid Receptor ◽  
Μ Opioid Receptors

Functional localization of specific receptors mediating gastrointestinal motor correlates of vomiting

1989 ◽  
Vol 256 (1) ◽  
pp. G92-G99 ◽  
Author(s):  
I. M. Lang ◽  
J. Marvig
Keyword(s):  
Small Intestine ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Sch 23390 ◽  
Receptor Antagonists ◽  
Motor Responses ◽  
Opioid Receptor Agonist ◽  
Opioid Receptor Antagonists ◽  
Gastrointestinal Motor

The gastrointestinal motor correlates of vomiting consist of two contractile events, 1) a giant retrogradely propagated contraction of the upper small intestine, the retrograde giant contraction (RGC) and 2) a series of post-RGC phasic contractions that occur primarily in the lower small intestine. The effects of cholinergic, dopaminergic, serotonergic, and opioid receptor antagonists and an opioid receptor agonist on vomiting and its gastrointestinal motor correlates initiated by apomorphine (APO), CuSO4, or cholecystokinin octapeptide (CCK-8) were determined in awake dogs. Atropine blocked the retrograde giant contraction only, and hexamethonium blocked all jejunoileal motor responses activated by APO, CuSO4, or CCK-8. Domperidone blocked all effects of APO only, whereas haloperidol, methysergide, 1-(1-naphthyl) piperazine, and fentanyl blocked or inhibited responses to both APO and CuSO4. None of the dopaminergic, serotonergic, or opioid receptor antagonists or the opioid receptor agonist affected the gastrointestinal motor responses to CCK-8. Cinanserin or Sch 23390 had no effect on any of the responses activated by APO, CuSO4, or CCK-8. These results suggested that D2 dopaminergic and 5-HT2 serotonergic receptors of the emetic central pattern generator mediate vomiting and its gastrointestinal motor correlates, whereas opioid receptors may mediate tonic inhibition of these responses. In addition, peripheral muscarinic or nicotinic cholinergic receptors but not peripheral 5-HT2, dopaminergic, or opioid receptors mediate the gastrointestinal motor correlates of vomiting.

scholarly journals The μ-opioid receptor agonist morphine, but not agonists at δ- or κ-opioid receptors, induces peripheral antinociception mediated by cannabinoid receptors

2008 ◽  
Vol 154 (5) ◽  
pp. 1143-1149 ◽  
Author(s):  
D Da Fonseca Pacheco ◽  
A Klein ◽  
A De Castro Perez ◽  
C M Da Fonseca Pacheco ◽  
J N De Francischi ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Cannabinoid Receptors ◽  
Opioid Receptor Agonist ◽  
Μ Opioid Receptor

scholarly journals The Differential Effects of a Selective Kappa-Opioid Receptor Agonist, U50488, in Guinea Pig Heart Tissues

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Chi-Feng Hung ◽  
Hsin-Ju Li ◽  
Hsun-Hao Chang ◽  
Gon-Ann Lee ◽  
Ming Jai Su
Keyword(s):  
Guinea Pig ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Right Atrium ◽  
Receptor Agonist ◽  
Negative Inotropic Effect ◽  
Contractile Force ◽  
Inotropic Effect ◽  
Opioid Receptor Agonist ◽  
Right Atria

The differential effects of a selective kappa- (κ-) opioid receptor agonist, U50488, were elucidated by monitoring the contraction of isolated guinea pig atrial and ventricular muscles. In electrically driven left atria, U50488 in nanomolar concentration range decreased the contractile force. Norbinaltorphimine (norBNI), a selectiveκ-receptor antagonist, and pertussis toxin (PTX) abolished the negative inotropic effect of U50488. In contrast, the inhibitory effect was not affected by the pretreatment of atropine or propranolol. Even though U50488 exerted a negative inotropic effect in the left atrium, it did not affect the contractile force of the right atrium and ventricles paced at 2 Hz. Similarly, the beating rate of the spontaneously beating right atrium was also unaffected by U50488. These results indicate that the activation ofκ-opioid receptors can only produce negative inotropic effect in left atria via activation of PTX-sensitive G protein in guinea pigs. The absence of negative inotropic effects in right atria and ventricles suggests that there may be a greater distribution of functionalκ-opioid receptors in guinea pig left atria than in right atria and ventricles, and the distribution of the receptors may be species-specific.

scholarly journals The δ Opioid Receptor Agonist SNC80 Selectively Activates Heteromeric μ–δ Opioid Receptors

2012 ◽  
Vol 3 (7) ◽  
pp. 505-509 ◽  
Author(s):  
Matthew D. Metcalf ◽  
Ajay S. Yekkirala ◽  
Michael D. Powers ◽  
Kelley F. Kitto ◽  
Carolyn A. Fairbanks ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Opioid Receptor Agonist ◽  
Δ Opioid Receptor

An antisense oligodeoxynucleotide to μ-opioid receptors inhibits μ-opioid receptor agonist-induced analgesia in rats

1995 ◽  
Vol 275 (1) ◽  
pp. 105-108 ◽  
Author(s):  
Xiao-Hong Chen ◽  
Jill U. Adams ◽  
Ellen B. Geller ◽  
J.Kim DeRiel ◽  
Martin W. Adler ◽  
...  
Keyword(s):  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Antisense Oligodeoxynucleotide ◽  
Opioid Receptor Agonist ◽  
Μ Opioid Receptor ◽  
Μ Opioid Receptors

Cardiovascular Properties of Metkephamid, a δ Opioid Receptor Agonist, in Man

1985 ◽  
Vol 68 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Fabrizio Pasanisi ◽  
Lesley Sloan ◽  
Peter C. Rubin
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Supine Position ◽  
Receptor Agonist ◽  
Noradrenaline Concentration ◽  
Opioid Receptor Agonist ◽  
Head Up Tilt ◽  
Δ Opioid Receptor

1. Opioid receptors exist in at least three forms: μ, δ and κ. Agonists at μ receptors produce orthostatic hypotension in man by a mechanism involving a reduction in baroreflex sensitivity. We describe here the cardiovascular properties of metkephamid, a relatively selective δ opioid receptor agonist. 2. Blood pressure, heart rate and plasma noradrenaline concentration were measured over a 7 h period in eight normal young male volunteers in the supine position and after 70° 5 min head-up tilt, after receiving metkephamid (50 mg intramuscularly) or placebo. 3. Metkephamid increased heart rate in the supine position with no change in blood pressure or plasma noradrenaline concentration. This was accompanied by symptoms consistent with an anti-muscarinic anticholinergic effect. 4. Head-up tilt resulted in substantial hypotension after metkephamid with an attenuated change in heart rate and no increase in noradrenaline concentration. 5. We conclude that δ as well as μ opioid receptor agonists can produce orthostatic hypotension with attenuation of heart rate response. Metkephamid possesses anticholinergic properties not seen with μ receptor agonists, suggesting a possible role of δ opioid receptors in cholinergic activity.

Renal responses to the κ-opioid-receptor agonist U-50488H in conscious lambs

2007 ◽  
Vol 293 (1) ◽  
pp. R162-R168 ◽  
Author(s):  
Wei Qi ◽  
K. Kumar Ebenezar ◽  
Mohamed A. Samhan ◽  
Francine G. Smith
Keyword(s):  
Opioid Receptor ◽  
Opioid Receptors ◽  
Receptor Agonist ◽  
Age Groups ◽  
Free Water ◽  
Urinary Flow ◽  
Free Water Clearance ◽  
Postnatal Maturation ◽  
Opioid Receptor Agonist ◽  
Renal Responses

In adult animals and humans, activation of κ-opioid receptors results in a diuresis. The aim of the present study was to investigate whether κ-opioids are also diuretic early in life and whether this is altered during postnatal maturation. Therefore, the renal effects of the κ-opioid-receptor agonist U-50488H were measured in two separate age groups of conscious lambs at two stages of postnatal maturation (∼1 wk and ∼6 wk) under physiological conditions. To evaluate whether the renal responses to U-50488H resulted from receptor-dependent effects, responses to U-50488H were also tested in the presence of the specific κ-opioid-receptor antagonist 5′-guanidinonaltrindole (GNTI). Urinary flow rate, free water clearance, and electrolyte excretions and clearances were measured for 30 min before and for 90 min after intravenous injection of U-50488H or vehicle. An increase in urinary flow rate accompanied by an increase in free water clearance occurred in response to administration of U-50488H but not vehicle. There were no effects of U-50488H on electrolyte excretions or clearances at either 1 or 6 wk of postnatal life. Although there were no effects of GNTI on any of the measured or calculated variables, the aforementioned diuretic response to U-50488H was abolished by pretreatment with GNTI in both age groups. We conclude that κ-opioid receptors are diuretic early in life and that this response does not appear to be altered as postnatal maturation proceeds. Therefore, these data provide evidence that activation of κ-opioid receptors early in life may lead to alterations in fluid balance.

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