Morphine mydriasis in mice

Korczyn, Amos D.; Boyman, Ruth; Shifter, Lia

doi:10.1016/0024-3205(79)90251-0

Cited by 26 publications

(10 citation statements)

References 8 publications

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“…Injection of morphine (30 mg/kg) induces mydriasis in small animals, such as mice and rats. The effect is primarily caused by a disruption of parasympathetic innervation of the iris (Korczyn et al, 1979;Murray et al, 1983). Pupillary diameters were measured using a binocular microscope (Olympus, Tokyo, Japan) with a magnification of 20X.…”

Section: Methodsmentioning

confidence: 99%

Deficiency of Nicotinic Acetylcholine Receptor β4 Subunit Causes Autonomic Cardiac and Intestinal Dysfunction

Wang

Orr-Urtreger

Chapman

et al. 2003

Molecular Pharmacology

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Neuronal nicotinic acetylcholine receptors (nAChR) are composed of 12 subunits (␣2-␣10 and ␤2-␤4), which play the central role in autonomic transmission. ␤4 subunits are abundantly expressed in autonomic ganglia, forming acetylcholine binding sites and ion channels with ␣3 or ␣3 and ␣5 subunits as pentameric receptors. To investigate the physiological and pharmacological properties of ␤4 subunits in autonomic ganglia, we measured autonomic functions in knockout mice lacking nAChR subunit ␤4 (␤4 Ϫ/Ϫ ) and wild-type mice. ␤4 Ϫ/Ϫ mice had an attenuated bradycardiac response to high frequency (60 pulse/s) vagal stimulation, as well as an increased sensitivity to hexamethonium blockade at low dose (3 mg/kg) and a reduced ileal contractile response to the nicotinic agonists cytisine, dimethylphenylpiperazinium iodide, nicotine (10 mg/kg each), and epibatidine (0.1 mg/kg). The results suggest that ␤4 subunits are important components of nAChRs in autonomic ganglia. Deficiency of ␤4 subunits altered ion channel properties, conductance, and sensitivity and affinity of receptors to agonists and antagonists, affecting ganglionic transmission.

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Section: Methodsmentioning

confidence: 99%

Deficiency of Nicotinic Acetylcholine Receptor β4 Subunit Causes Autonomic Cardiac and Intestinal Dysfunction

Wang

Orr-Urtreger

Chapman

et al. 2003

Molecular Pharmacology

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“…The pupillary diameters were measured as previously described [Korczyn et al, 1979]. In short, nonaneslheti/.cd animals were held under a Zeiss binocular operating microscope fitted with a graded ocular, using a magnification of 20.…”

Section: Methodsmentioning

confidence: 99%

“…In several species, how ever, opiates cause mydriasis [Klemfuss et al, 1978;Korczyn et al, 1979;Murray et al. 1983], The pupillary effects of opiates are thought to be of central origin [Lee and Wang, 1975;Korczyn and Maor, 1981;Murray et al, 1983], Morphine mydriasis is naloxone-reversible [Korczyn and Rock, 1981], Enkephalins also cause naloxone-sen sitive mydriasis prob ably by acting on opiate receptors in the brain.…”

Section: Introductionmentioning

confidence: 99%

Opioid Mydriasis: Cross-Tolerance between Morphine and Enkephalins

Ben-Am¹,

Korczyn²

1986

Pharmacology

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The occurrence of cross-tolerance between morphine and met-enkephalin, and between morphine and DADL (D-Ala-D-Leu-enkephalin) in causing mydriasis in mice was studied. Morphine-tolerant mice treated with met-enkephalin or DADL intracerebroventric-ularly (ICV) showed marked reduction of the pupillary effect of the endopioids. Maximal mydriasis in tolerant animals was only about 30% for met-enkephalin and 50% for DADL, compared to levels in nontolerant animals. These results are among the first to demonstrate cross-tolerance between morphine and enkephalins in intact animals and may suggest involvement of multiple opiate receptor systems in producing mydriasis.

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“…Naive male ICR albino mice (Swiss strain), weighing 20-40 g were used. Pupil diameters were measured with a magnification of x20 as previously described (Korczyn, Boyman & Shifter, 1979). All drugs were injected intraperitoneally to groups of 8-10 mice.…”

Section: Introductionmentioning

confidence: 99%

“…All drugs were injected intraperitoneally to groups of 8-10 mice. Morphine hydrochloride was given at a dose of 100 mg/kg, producing maximal mydriasis (Korczyn et al, 1979) (Snedecor & Cochran, 1967). Separate groups of animals were also injected with the antagonists without morphine pretreatment.…”

Section: Introductionmentioning

confidence: 99%

Antagonism of Opiate Mydriasis in Mice

Korczyn

Rock

1981

British J Pharmacology

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I Morphine-induced mydriasis in mice is antagonized by nalorphine, levallorphan and naloxone in a dose-dependent manner. 2 The relative potency of the three agents is 10: 56: 134 respectively, thus being in accordance with other tests of narcotic antagonism. Naloxone has the shortest duration of action. 3 When injected into naive animals, nalorphine (but not levallorphan or naloxone) produces a slight mydriasis. 4 Measurement of the diameter of the pupil in mice seems to be a precise, simple and rapid test for studying narcotic antagonist as well as agonist action and has several advantages over standard methods used for this purpose.

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Morphine mydriasis in mice

Cited by 26 publications

References 8 publications

Deficiency of Nicotinic Acetylcholine Receptor β4 Subunit Causes Autonomic Cardiac and Intestinal Dysfunction

Deficiency of Nicotinic Acetylcholine Receptor β4 Subunit Causes Autonomic Cardiac and Intestinal Dysfunction

Opioid Mydriasis: Cross-Tolerance between Morphine and Enkephalins

Antagonism of Opiate Mydriasis in Mice

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