Effect of etorphine on the spontaneous and field stimulation-mediated release of norepinephrine and total tritium from perfused guinea pig hearts

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5243134

Isolated guinea pig hearts were prelabeled with /sup 3/H-norepinephrine (/sup 3/H-NE) and perfused with modified Krebs-bicarbonate solution at 37/sup 0/C. Spontaneous release of total /sup 3/H and field stimulation-mediated (supramax. V., 1 Hz, 2 msec duration for a total of 60 pulses) overflow of NE and /sup 3/H-NE were measured in the absence or presence of etorphine. Etorphine (0.1 - 100 ..mu..M) was added to the perfusion fluid 15 min. before the stimulation. To study the effect of etorphine on spontaneous release of total /sup 3/H, etorphine was added cumulatively without stimulation. Etorphine (1.0 - 100 ..mu..M) caused a significant decrease in the stimulation-mediated overflow of NE and the inhibition was dose-related. The overflow of NE was 5.1 +/- 0.3 ng in the absence and 4.0 +/- 0.2 ng in the presence of etorphine (1.0 ..mu..M). Low concentrations of etorphine (0.1 - 1.0 ..mu..M) had no effect on the spontaneous release of total /sup 3/H while 10 ..mu..M and 100 ..mu..M caused a 3 and 6-fold increase respectively. The results show that etorphine inhibited neuronal release of NE at a dose which had no effect on spontaneous release. It is suggested that opiate receptors might be involved in the prejunctional modulation of the release of NE in the guinea pig heart.

• Research Organization: Univ. of Kansas, Lawrence
• OSTI ID: 5243134
• Report Number(s): CONF-8604222-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
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ANALGESICS
BIOLOGICAL EFFECTS
NORADRENALINE
SECRETION
GUINEA PIGS
HEART
NARCOTICS
PERFUSED ORGANS
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ADRENAL HORMONES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DRUGS
HORMONES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RODENTS
STEROID HORMONES
SYMPATHOMIMETICS
VERTEBRATES
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