To study the function of catecholamines in the late period of avian embryogenesis, the time course of plasma catecholamines, the release of catecholamines by hypoxia and finally the effect of adrenergic agents on blood parameters and on circulation were recorded. The experiments reveal a temporary increase in plasma adrenaline and noradrenaline shortly before internal pipping occurs. On the other hand a premature increase of plasma catecholamines is induced by hypoxia. Furthermore, treating the embryo with adrenergic agents such as adrenaline, noradrenaline and phenylephrine resulted in changes of blood gas parameters: increase of PO2, O2-saturation and negative base excess, decrease of PCO2 and HCO3-. In addition, exogenous adrenaline and noradrenaline released an increase in the blood flow and an enhanced hemoglobin content in the chorioallantoic membrane, but not in the kidneys. Finally, adrenaline caused a decrease of 2,3 DPG and an increase of lactate in the plasma. The data indicate that hypoxia, which is formed normally towards the end of embryogenesis, induces an increased secretion of catecholamines which in turn improves the blood gas status. In this way the embryo is protected from deleterious hypoxic damages. This conclusion has been derived from experiments, in which the release of catecholamines was blocked under hypoxia. Under these conditions a significant increase in the mortality rate was observed.
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http://dx.doi.org/10.1016/0034-5687(91)90056-o | DOI Listing |
J Biol Methods
November 2024
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, United States.
Background: Current multimodal neuroimaging plays a critical role in studying clinical conditions such as cardiovascular disease, major depression, and other disorders related to chronic stress. These conditions involve the brainstem-hypothalamic network, specifically the locus coeruleus (LC), dorsal vagal complex (DVC), and paraventricular nucleus (PVN) of the hypothalamus, collectively referred to as the "DVC-LC-PVN circuitry." This circuitry is strongly associated with the norepinephrine (NE) and epinephrine (E) neurotransmitter systems, which are implicated in the regulation of key autonomic functions, such as cardiovascular and respiratory control, stress response, and cognitive and emotional behaviors.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Department of Pharmacology, Faculty of Medicine, Erzincan Binali Yildirim University, Erzincan, Türkiye.
Aim: The current study aimed to investigate the protective effects of adenosine triphosphate (ATP), metyrosine, and melatonin on possible methylphenidate cardiotoxicity in rats using biochemical and histopathological methods.
Methods: Thirty rats were separated into five groups: healthy (HG), methylphenidate (MP), ATP + methylphenidate (ATMP), metyrosine + methylphenidate (MSMP), and melatonin + methylphenidate (MLMP). ATP (5 mg/kg) was given intraperitoneally once daily, metyrosine (50 mg/kg) orally twice daily, and melatonin (10 mg/kg) orally once daily.
Am J Transl Res
December 2024
Department of Anesthesiology, Xi'an Central Hospital No. 161, Xiwu Road, Xincheng District, Xi'an 710003, Shaanxi, China.
Objective: To evaluate the effects of preemptive hydromorphone analgesia on postoperative delirium and stress response in patients undergoing laparoscopic cholecystectomy.
Methods: A retrospective cohort study was conducted, including 167 patients who underwent laparoscopic cholecystectomy at Xi'an Central Hospital between June 2021 and November 2023. Patients were categorized into an observation group (n=87) receiving preemptive hydromorphone hydrochloride analgesia and a control group (n=80) without preemptive analgesia.
J Chromatogr Sci
January 2025
Division of Chemical and Material Metrology, Korea Research Institute of Standards and Science, 267, Gajeong-ro, Yuseong-gu, Daejeon, 34113Republic of Korea.
We developed a reversed-phased high-performance liquid chromatographic method combining ultraviolet detection and integrated pulsed amperometric detection for the simultaneous quantification of dopamine, 5-hydroxyindolacetic acid, homovanillic acid, serotonin, 3,4-dihydroxyphenylacetic acid, norepinephrine and epinephrine. All target components were completely separated in a C18 column with isocratic elution of 5% acetonitrile solution containing 8 mM HClO4 and 0.20 mM 1-octanesulfonic acid as an ion pairing reagent.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Analytic Biochemistry, Calculi and Manual Chemistry, Mass Spectrometry, ARUP Laboratories, Inc., Salt Lake City, UT, USA.
Metanephrines (metanephrine [MN] and normetanephrine [NMN]) are O-methylated metabolites derived from the catecholamines, epinephrine, and norepinephrine, respectively. High concentrations of metanephrines have been observed in individuals with pheochromocytoma, a neuroendocrine tumor. Measurement of metanephrines in urine is used to screen for the tumor.
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