Effect of α1- and α2-Adrenoceptor Agorists and Antagonists on ACTH Secretion in Intact and in Hypothalamic Deafferentated Rats

Shimizu, Kanichiro

doi:10.1254/jjp.36.23

Cited by 21 publications

(10 citation statements)

References 40 publications

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“…The increase in corticosterone concentration induced by phentolamine is in agreement with the observation of Shimizu (1984), who found that the drug in question used in doses of 5 mg/kg or higher stimulates the ACTH secretion. …”

Section: Resultssupporting

confidence: 91%

“…Dexamethasone decreased the plasma corticosterone concentration (though ACTH (Shimizu, 1984) concentrations on its own-it was high enough to effectively block the elevation of corticosterone level induced by the %-adrenoceptor agonist clonidine (Przegalifiski etal., 1989). The increase in corticosterone concentration induced by phentolamine is in agreement with the observation of Shimizu (1984), who found that the drug in question used in doses of 5 mg/kg or higher stimulates the ACTH secretion.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Oxaprotiline enantiomers stimulate ACTH and corticosterone secretion in the rat

Przegaliński

Budziszewska

Grochmal

1991

J. Neural Transmission

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The effect of oxaprotiline (OXA) enantiomers--of which (+)-OXA inhibits noradrenaline (NA) uptake, whereas (-)-OXA does not--on the secretion of adrenocorticotropin hormone (ACTH) and corticosterone was studied in rats. Both enantiomers dose-dependently and with a similar potency increased the plasma level of ACTH and corticosterone, the effect of (-)-OXA on corticosterone being of a longer duration. The stimulation of ACTH secretion and the inability of (+)- and (-)-OXA to increase the plasma corticosterone concentration in animals pretreated with dexamethasone indicate that secretion of the latter hormone results from the action of the enantiomers at a level superior to the adrenal cortex, i.e. the hypothalamus/pituitary. The corticosterone response to (+)- or (-)-OXA was not modified in rats with a selective lesion of NA nerve endings induced by the neurotoxin DSP-4, nor was it affected by the selective alpha 1-antagonist prazosin, the selective alpha 2-antagonist yohimbine, the mixed alpha 1/alpha 2-antagonist phentolamine, the selective dopamine (D2) receptor antagonist sulpiride and the non-selective 5-hydroxytryptamine (5-HT) receptor antagonist metergoline. These results indicate that neither the NA system nor D2 and 5-HT receptors are involved in the hormonal response to the OXA enantiomers. Although the (+)- and (-)-OXA-induced stimulation of corticosterone secretion was not antagonized by diazepam, ipsapirone, naloxone, or propranolol, it cannot be excluded that both these enantiomers act as non-specific stressors.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Oxaprotiline enantiomers stimulate ACTH and corticosterone secretion in the rat

Przegaliński

Budziszewska

Grochmal

1991

J. Neural Transmission

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“…Shimizu 35 stated that agonists (NE and PE) of 36 Handley and Mithani, 37 Yorimitsu et al 38 Jager et al 39 stated that doxazosin had a negative effect on aldosterone secretion by adrenocortical cells porcine. Mulatero et al 40 found that an intravenous administration of doxazosin to patients with primary aldosteronism significantly lowered plasma aldosterone concentration.…”

Section: Discussionmentioning

confidence: 99%

Influence of doxazosin on biosynthesis of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats

Kasacka

Piotrowska

Filipek

et al. 2015

Exp Biol Med (Maywood)

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Hypertension frequently results in severe complications in cardiovascular system and histopathological changes in the heart. To better understand the cellular processes and signaling pathways responsible for the proper functioning of the heart, we decided to check whether doxazosin affects the density of structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats. The aim of this study is to find differences in the density of the structures containing S100A6 and atrial natriuretic factor in the heart of spontaneously hypertensive rats treated with doxazosin compared to untreated animals. Fragments of heart were collected from five spontaneously hypertensive rats and five spontaneously hypertensive rats receiving doxazosin for six weeks (dose 0.1 mg per 1 kg of body weight). On the paraffin sections S100A6 and atrial natriuretic factor peptides were localized in the heart using immunohistochemistry. Positive immunohistochemical reaction for S100A6 was observed in atrial and ventricular cardiomyocytes and in the coronary vasculature. In the heart of hypertensive rats treated with doxazosin the S100A6 immunoreactivity was significantly lower compared to untreated animals. Immunodetection of atrial natriuretic factor in the heart of rats confirmed presence of peptide in atrial myocardium. Delicate atrial natriuretic factor-immunoreactivity was observed also in few ventricular cardiomyocytes. The atrial natriuretic factor-immunosignal was significantly weaker in hearts of hypertensive rats receiving doxazosin compared to spontaneously hypertensive rats untreated. Since we found that doxazosin reduces the levels of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats, it can be assumed that cardiovascular disorders that occur in hypertension may be associated with disturbances of cellular processes and signaling pathways.

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“…On this basis, the stress-reduction hypothesis may be tentatively related to the binding data summarized above, showing that the most significant increase of the cx2-adrenoceptors was observed in the hypothalamus. Moreover, there is clear evidence that noradrenaline inhibits corticotrophin (ACTH) secretion by an action on the hypothalamus (see reviews in Amaral & Sinnamon, 1977;Ganong, 1980;Jones et al, 1984), and it seems that the inhibition of the corticotrophin-releasing factor by noradrenaline is mediated by an cx-adrenoceptor mechanism (Buckingham & Hodges, 1979;Ganong, 1980;Shimizu, 1984). Thus, it is conceivable that the increase in number of hypothalamic cx2-receptors observed after stimulation of the LC modulates the noradrenergic control of the ACTH release.…”

Section: Discussionmentioning

confidence: 99%

Long-term modulation of learning following locus coeruleus stimulation: Behavioral and neurochemical data

Velly

Kempf²,

Cardo³

et al. 1985

Psychobiology

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This paper summarizes some behavioral and neurochemical data relating to the delayed effect oflocus coeruleus stimulation on the learning capabilities ofthe rat. The first observation showed that electrical stimulation of the locus coeruleus of a 15-day-old rat improved the acquisition and extinction of a food-reinforced operant task performed 4 weeks later. The neurochemical lesion of the dorsal noradrenergic bundle, 10 days before the stimulation, did not decrease the behavioral effect, whereas the neurochemical lesion of the locus coeruleus proper suppressed the improvement. Furthermore, we studied the long-term effect of the stimulation on some biochemical parameters of the coerulean system: First, the turnover of noradrenaline increased in the locus coeruleus 4 days after the stimulation, whereas it decreased 4 weeks after the treatment in the nucleus proper and in the hippocampus. Second, 4 weeks after the stimulation, the characteristics of some adrenoceptor populations were significantly changed, in particular regions of the brain. The number of al"adrenoceptors was increased in the cortex, the hippocampus, and particularly the hypothalamus. The number of al-adrenoceptors was increased in the cortex. Neither the number nor the affinity of {3 receptors was altered by the stimulation. Likewise, the number of al-, a,-, and {3-adrenoceptors in the brainstem was not changed. These results are discussed. To explain our behavioral data, we assume that the performance improvement in prestimulated rats is due, for the most part, to a reduced reaction to stressful situations. On this basis, the stressreduction hypothesis is tentatively related to the binding data showing that the most significant increase of the a2-receptors was observed in the hypothalamus.In previous studies, we showed that electrical stimulation of the lateral hypothalamus of 15-day-old rats significantly enhanced the learning of various tasks examined 4 weeks later. We first demonstrated that this stimulation improved the acquisition and extinction of a foodreinforced task (Velley & Cardo, 1977). In subsequent experiments, we observed the same effect on the acquisition and reversal of a light-dark discrimination, whether appetitively or aversively reinforced, as well as on the acquisition of a one-way avoidance task (Velley, Chassaing, & Cardo, 1981).

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Effect of α1- and α2-Adrenoceptor Agorists and Antagonists on ACTH Secretion in Intact and in Hypothalamic Deafferentated Rats

Cited by 21 publications

References 40 publications

Oxaprotiline enantiomers stimulate ACTH and corticosterone secretion in the rat

Oxaprotiline enantiomers stimulate ACTH and corticosterone secretion in the rat

Influence of doxazosin on biosynthesis of S100A6 and atrial natriuretic factor peptides in the heart of spontaneously hypertensive rats

Long-term modulation of learning following locus coeruleus stimulation: Behavioral and neurochemical data

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