In cats anaesthetized with pentobarbital sodium, the posterior hypothalamus was superfused and electrically stimulated with a push-pull cannula. The pressor response to stimulation of this hypothalamic area was inhibited when the hypothalamus was superfused with drugs blocking either alpha-adrenoreceptors (piperoxan, tolazoline), or beta-adrenoreceptors--(+/-)-propranolol, (-)-propranolol, practolol, sotalol, metoprolol. (+)-Propranolol and a concentration of procaine equianaesthetic to propranolol were ineffective. During superfusion with tolazoline in the presence of practolol the inhibition was twice as that when the hypothalamus was superfused with either tolazoline or practolol. In another series of experiments the push-pull cannula was inserted into the anterior hypothalamus. The depressor response to stimulation of this area was inhibited by the hypothalamic superfusion with the alpha-adrenoreceptor blocking drugs phentolamine, tolazoline, piperoxan or yohimbine. Hypothalamic superfusion with phenylephrine abolished the inhibitory effect of phentolamine on the depressor response. The results indicate that adrenoreceptors are present in the hypothalamus and that they are involved in blood pressure changes elicited by hypothalamic stimulation.
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http://dx.doi.org/10.1159/000400630 | DOI Listing |
Naunyn Schmiedebergs Arch Pharmacol
July 2023
Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Kranebitter Allee 26, A-6020, Innsbruck, Austria.
Use of the demanding techniques microdialysis or push-pull superfusion makes it possible to identify neurons in distinct brain areas involved in central control of peripheral functions, thus enabling brain mapping. Investigations with the push-pull superfusion technique have shown that mainly catecholaminergic neurons of the posterior and anterior hypothalamus, the locus coeruleus, and the nucleus of the solitary tract are of crucial importance for blood pressure regulation. Experimentally induced blood pressure changes also modify the release of histamine, glutamate, and taurine in the posterior hypothalamus and of serotonin in the locus coeruleus.
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January 2023
School of Biological Sciences, National Institute of Science Education and Research (NISER)-Bhubaneswar, Jatani 752050, India.
In contrast to mammals, birds have a higher basal metabolic rate and undertake wide range of energy-demanding activities. As a consequence, food deprivation for birds, even for a short period, poses major energy challenge. The energy-regulating hypothalamic homeostatic mechanisms, although extensively studied in mammals, are far from clear in the case of birds.
View Article and Find Full Text PDFBiochem Biophys Res Commun
July 2022
Center for Integrative Physiology Division of Integrative Physiology, Kansai Electric Power Medical Research Institute, Kobe, Japan; Division of Diabetes, Metabolism and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan; Department of Diabetes, Endocrinology and Metabolism/Rheumatology and Clinical Immunology, Gifu University Graduate School of Medicine, Gifu, Japan. Electronic address:
A rare sugar D-Allulose has sweetness without calorie. Previous studies have shown that D-Allulose improves glucose and energy metabolism and ameliorates obesity. However, underlying mechanisms remain elusive.
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April 2022
Brain Health Research Centre, Centre for Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, Aotearoa New Zealand.
The hormone, oxytocin, is synthesised by magnocellular neurones of the supraoptic and paraventricular nuclei and is released from the posterior pituitary gland into the circulation to trigger uterine contractions during parturition. Kisspeptin fibre density increases around the supraoptic nucleus over pregnancy and intracerebroventricular kisspeptin excites oxytocin neurones only in late pregnancy. However, the mechanism of this excitation is unknown.
View Article and Find Full Text PDFJ Comp Physiol B
January 2020
Institute of Veterinary Physiology and Biochemistry, Justus-Liebig-University, Frankfurter Strasse 100, 35392, Gießen, Germany.
In 4-5-month-old chicken, intravenous injections of bacterial lipopolysaccharide (LPS) induced a dose-dependent fever response and a pronounced increase of circulating interleukin-6 (IL-6). To assess a possible role for IL-6 in the brain of birds, a hypothalamic neuro-glial primary culture from 1-day-old chicken was established. Each well of cultured hypothalamic cells contained some 615 neurons, 1350 astrocytes, and 580 microglial cells on average.
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