Background: Intravenous epinephrine (EPI) is used as a pharmacologic agent to acutely treat patients in cardiac arrest. Unfortunately, there have been several homicide cases where hospitalized patients died due to a purposeful overdose of epinephrine. We measured plasma epinephrine metabolites (metanephrine, MET, and normetanephrine, NMET) to determine if exogenous epinephrine can be distinguished from endogenous epinephrine concentrations in a controlled animal study.
Methods: Rabbits were subjected to three different protocols. In the physiologic stress group (n=8), rabbits were immobilized for 30 min in a restraining tube. In the sub-lethal dose (n=9), 0.01 mg/kg of epinephrine was injected into anesthetized rabbits. In the lethal dose group (n=8), 1.0 mg/kg of epinephrine was administered into anesthetized rabbits. Blood was collected at regular intervals for up to 480 min. The plasma metanephrine and normetanephrine concentrations were measured by liquid chromatography/mass spectrometry and the serum cortisol concentrations by immunoassay.
Results: Serum cortisol and plasma metanephrine and normetanephrine concentrations increased in the stressed animals during immobilization demonstrating the endogenous stress model. Following a sub-therapeutic epinephrine dose, plasma metanephrine increased while plasma normetanephrine decreased. The peak plasma metanephrine concentrations were similar to the concentrations observed in the stressed animals; however, the ratio of plasma metanephrine to normetanephrine was significantly different. In the lethal epinephrine dose, both the plasma metanephrine concentrations and ratio of metabolites were significantly greater than those observed in the endogenously stressed animals.
Conclusions: The ratio of plasma metanephrine to normetanephrine is the best marker to determine the presence of exogenous therapeutic and lethal epinephrine administration. However, there were limitations to the study design that could alter these conclusions.
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http://dx.doi.org/10.1016/j.cccn.2004.07.018 | DOI Listing |
J Clin Endocrinol Metab
December 2024
Unidade de Adrenal, Laboratório de Endocrinologia Molecular e Celular LIM25, Divisão de Endocrinologia e Metabologia, Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, 01246-903, Brasil.
Context: The role of plasma metanephrine in adrenal venous sampling (AVS) for assessing lateralization in primary aldosteronism (PA) requires further clarification.
Objective: To evaluate the performance of plasma metanephrine in AVS for determining aldosterone lateralization in PA, with or without mild autonomous cortisol secretion (MACS).
Methods: Sequential AVS under cosyntropin stimulation was conducted in 58 consecutive patients with PA and indication for AVS.
Endocrinol Diabetes Metab Case Rep
October 2024
Summary: Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant condition characterized by multiple cutaneous and uterine leiomyomas and renal cell cancer (RCC). HLRCC is caused by germline pathogenic/likely pathogenic (P/LP) variants in the fumarate hydratase (FH) gene on chromosome 1q42.3, encoding the mitochondrial enzyme responsible for the conversion of fumarate to malate in the Krebs cycle.
View Article and Find Full Text PDFBMJ Case Rep
December 2024
General Surgery, Gold Coast University Hospital, Southport, Queensland, Australia.
Pflugers Arch
November 2024
Institute of Physiology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
Increased dietary inorganic phosphate (P) intake stimulates renal P excretion, in part, by parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23) or dopamine. High dietary P may also stimulate sympathetic outflow. Rodent studies provided evidence for these regulatory loops, while controlled experiments in healthy humans examined periods of either a few hours or several weeks, and often varied dietary calcium intake.
View Article and Find Full Text PDFAnn Clin Biochem
November 2024
Centre for Medical Education, Queen's University Belfast, Belfast, UK.
Background: As cortisol and metanephrine are involved in the stress response, it is often recommended that individuals are relaxed at the time of venepuncture, however, evidence behind these recommendations is lacking. We investigated the effects of acute psychological stress on serum cortisol and plasma metanephrine concentrations in healthy individuals exposed to varying levels of psychological stress and compared these results to self-reported measures of stress.
Methods: Ten medical students completed two medical in-person simulations (one low-complexity, one high-complexity) in a random order.
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