Noradrenaline release in the median preoptic and paraventricular nuclei by hemorrhage in rats

2000 ◽  
Vol 38 ◽  
pp. S165
Author(s):  
K Sakamaki
1982 ◽  
Vol 48 (01) ◽  
pp. 062-066 ◽  
Author(s):  
Chantal Legrand ◽  
Véronique Dubernard ◽  
Philippe Meyer

Summary(3H) noradrenaline was taken up by human platelets and partially converted into sulfoconjugated noradrenaline. This uptake was inhibited by drugs which have been previously shown to impair the uptake of 5-HT (ouabain, chlorimipramine) or the storage of 5-HT (tyramine, reserpine) by platelets. In addition, tyramine and reserpine stimulated the formation of sulfoconjugated noradrenaline. The efflux of noradrenaline from platelets was measured in parallel and was found to be directly related to the proportion of non metabolized to metabolized noradrenaline in the cells. Unlike tyramine, which induced a similar release of noradrenaline and 5-HT, reserpine was less effective at inducing noradrenaline release than 5-HT release. This study indicates a preferential localization of noradrenaline in the granular pool of human platelets with the existence of an extragranular sulfoconjugated pool which is increased when the granular storage of noradrenaline is impaired. Studies of noradrenaline fluxes and metabolism may be useful in the understanding of both acquired and inherited platelet storage pool defects.


1962 ◽  
Vol 41 (2) ◽  
pp. 301-313 ◽  
Author(s):  
S. Horowitz ◽  
J. J. Van der Werff ten Bosch

ABSTRACT Electrolytic lesions were placed in the anterior hypothalamus of 3–4 day-old female rats; vaginal opening was hastened in comparison with blank-operated littermates in 12 of 17 rats bearing a lesion in the basal supra-and post-chiasmatic area. In the animals with the earliest vaginal opening, lesions reached upward towards the region of the anterior commissure and the paraventricular nuclei. The degree of advancement of puberty in rats operated at the age of 3 or 4 days was similar to that caused by lesions made at 10, 14 or 15 days. This finding suggests that the effect of a lesion upon gonadotrophin secretion does not begin to take place until after the age of at least two weeks.


1993 ◽  
Vol 18 ◽  
pp. S215
Author(s):  
Hiroshi Kawahara ◽  
Masami Yoshida ◽  
Hideyasu Yokoo ◽  
Masakatsu Nishi ◽  
Masatoshi Tanaka

2012 ◽  
Vol 8 (4) ◽  
pp. 677-692 ◽  
Author(s):  
Edin Ibrisimovic ◽  
Helmut Drobny ◽  
Qiong Yang ◽  
Thomas Höfer ◽  
Stefan Boehm ◽  
...  

Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2681-2688 ◽  
Author(s):  
Sathya Velmurugan ◽  
Paula J. Brunton ◽  
Gareth Leng ◽  
John A. Russell

Secretin is a 27-amino acid brain-gut peptide from duodenal S-cells. We tested the effects of systemic administration of secretin to simulate its postprandial release on neuroendocrine neurons of the supraoptic nucleus (SON) in urethane-anesthetized female rats. Secretin dose-dependently increased the firing rate of oxytocin neurons, more potently than cholecystokinin, and dose-dependently increased plasma oxytocin concentration. The effect of secretin on SON vasopressin neurons was also predominantly excitatory, in contrast to the inhibitory actions of cholecystokinin. To explore the involvement of noradrenergic inputs in secretin-induced excitation, benoxathian, an α1-adrenoceptor antagonist, was infused intracerebroventricularly. Benoxathian intracerebroventricular infusion blocked the excitation by secretin of both oxytocin and vasopressin neurons. To test the role of local noradrenaline release in the SON, benoxathian was microdialyzed onto the SON. The basal firing rate of oxytocin neurons was slightly reduced and the secretin-induced excitation was attenuated during benoxathian microdialysis. Hence, noradrenergic pathways mediate the excitation by systemic secretin of oxytocin neurons via α1-adrenoceptors in the SON. As both systemic secretin and oxytocin are involved in regulating gastrointestinal functions and natriuresis, systemically released secretin might act partly through oxytocin.


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