Andrew V Turnbull

Andrew V Turnbull
  • AstraZeneca

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90
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Introduction
Skills and Expertise
Current institution
AstraZeneca

Publications

Publications (90)
Data
Supplementary Figure S2 Body weight to energy intake in human for placebo‐corrected data (step 1).
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Supplementary Figure S6 Fundamental operations on model representations of the biomarker chain.
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Supplementary Figure S3 Body weight to energy intake in human for placebo‐corrected data (step 1). Transformed summary curves of the 14 clinical studies reported in Supplementary Figure S2.
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Supplementary Figure S5 Residual plots corresponding to the model fit in Figure 4.
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Supplementary Text. Further details on steps 1–3.
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Supplementary Figure S1 Body weight to energy intake in human (step 1). Transformed summary curves of the 14 clinical studies reported in Figure 2.
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Supplementary Figure S4 Model selection for body‐weight reduction to receptor occupancy in the mouse (step 2).
Article
Full-text available
In this study, we present the translational modeling used in the discovery of AZD1979, a melanin-concentrating hormone receptor 1 (MCHr1) antagonist aimed for treatment of obesity. The model quantitatively connects the relevant biomarkers and thereby closes the scaling path from rodent to man, as well as from dose to effect level. The complexity of...
Article
Background and purpose: Melanin-concentrating hormone (MCH) is an orexigen and while rodents express one MCH receptor (Mchr1), humans, non-human primates and dogs express two MCH receptors (MCHR1 and MCHR2). MCHR1 antagonists have been developed for the treatment of obesity and lower body weight in rodents. However, the mechanisms for the body wei...
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Full-text available
Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is a key enzyme in triacylglycerol (TG) biosynthesis. Here we show that genetic deficiency and pharmacological inhibition of DGAT1 in mice alters cholesterol metabolism. Cholesterol absorption, as assessed by acute cholesterol uptake, was significantly decreased in the small intestine and liver upon...
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Type 2 diabetes (T2D) occurs when there is insufficient insulin release to control blood glucose, due to insulin resistance and impaired β-cell function. The GPR39 receptor is expressed in metabolic tissues including pancreatic β-cells and has been proposed as a T2D target. Specifically, GPR39 agonists might improve β-cell function leading to more...
Data
Chemistry synthesis and experimental details. (PDF)
Article
Diacylglycerol acyl transferase 1 (DGAT1) catalyzes the final step in triglyceride (TG) synthesis, the conversion of diacylglycerol (DAG) to TG. Dgat1-/- mice exhibit a number of beneficial metabolic effects including reduced obesity and improved insulin sensitivity and no known cardiac dysfunction. In contrast, failing human hearts have severely r...
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Full-text available
Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final step in triglyceride synthesis, the conversion of diacylglycerol (DAG) to triglyceride. Dgat1−/− mice exhibit a number of beneficial metabolic effects including reduced obesity and improved insulin sensitivity and no known cardiac dysfunction. In contrast, failing human hearts have severe...
Article
11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) has been widely considered by the pharmaceutical industry as a target to treat the metabolic syndrome in type II diabetics. We hypothesized that CNS penetration might be required to see efficacy. Starting from a previously reported pyrimidine compound, we removed hydrogen bond donors to yield 3, wh...
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The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a target for novel type 2 diabetes and obesity therapies based on the premise that lowering tissue glucocorticoids will have positive effects on body weight, glycaemic control and insulin sensitivity. An 11β-HSD1 inhibitor (compound C) inhibited liver 11β-HSD1 by >90%, but only led to...
Article
Metabolic syndrome (MetS) is growing in importance with the rising levels of obesity, type 2 diabetes and insulin resistance. MetS shares many characteristics with Cushing's syndrome which has led to investigation of the link between excess glucocorticoids and MetS. Indeed, increased glucocorticoids from intracellular regeneration by 11β-hydroxyste...
Article
Glucocorticoids act on several major neuropeptide networks in the hypothalamus which are important for regulation of energy balance and insulin sensitivity. Active glucocorticoids (cortisol/corticosterone in humans/rodents) can be regenerated from their inactive forms by the enzyme 11β-hydroxysteroid dehydrogenase type one (11β-HSD1) which is expre...
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Full-text available
Acyl CoA:diacylglycerol acyltransferase-1 (DGAT-1) catalyzes the final step in triacylglycerol (TAG) synthesis and is highly expressed in the small intestine. Because dgat-1-/- mice are resistant to diet-induced obesity, we investigated the acute effects of intragastric (IG) infusion of a small molecule DGAT-1 inhibitor (DGAT-1i) on eating, circula...
Article
Acyl-coenzyme A: cholesterol O-Acyltransferase (ACAT) and Acyl-coenzyme A: diacylglycerol O-acyltransferase (DGAT) enzymes play important roles in synthesizing neutral lipids, and inhibitors of these enzymes have been investigated as potential treatments for diabetes and other metabolic diseases. Administration of a Acyl-coenzyme A: diacylglycerol...
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Full-text available
A novel series of potent diacylglycerol acyl transferase 1 inhibitors was developed from the clinical candidate AZD3988. Replacement of the phenyl cyclohexyl-ethanoate side chain with substituted oxy-linked side chains to introduce changes in shape and polarity, reduce lipophilicity and mask the hydrogen bond donors with internal hydrogen bond acce...
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Full-text available
Inhibition of diacylglycerol acetyl transferase 1 is of great interest in the treatment of diabetes, obesity and other diseases that constitute the metabolic syndrome. Small molecule inhibitors of the enzyme are often dogged with physicochemical property-related problems such as poor solubility. Herein, the optimisation of a series of biphenyl acet...
Article
A new series of pyrazinecarboxamide DGAT1 inhibitors was designed to address the need for a candidate drug with good potency, selectivity and physical and DMPK properties combined with a low predicted dose in man. Rational design and optimisation of this series led to the discovery of compound 30 (AZD7687) which met the project objectives for poten...
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Full-text available
Acyl CoA:diacylglycerol acyltransferase (DGAT) 1 catalyzes the final step of triglyceride (TG) synthesis. We show that acute administration of a DGAT1 inhibitor (DGAT1i) by oral gavage or genetic deletion of intestinal Dgat1 (intestine-Dgat1(-/-)) markedly reduced postprandial plasma TG and retinyl ester excursions by inhibiting chylomicron secreti...
Article
A novel series of DGAT-1 inhibitors was discovered from an oxadiazole amide high throughput screening (HTS) hit. Optimisation of potency and ligand lipophilicity efficiency (LLE) resulted in a carboxylic acid containing clinical candidate 53 (AZD3988), which demonstrated excellent DGAT-1 potency (0.6 nM), good pharmacokinetics and pre-clinical in v...
Article
Ingested nutrients stimulate the release of GLP-1 and PYY from enteroendocrine L-cells, but the mechanisms of this effect are still elusive. Triacylglycerol (TAG) synthesis may somehow interfere with GLP-1 and PYY release because mice deficient in diacylglycerol acyltransferase-1 (DGAT-1), a key enzyme in TAG synthesis, showed increased plasma leve...
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Full-text available
Diacylglycerol (DAG) acyl transferase 1 (Dgat1) knockout ((-/-)) mice are resistant to high-fat-induced obesity and insulin resistance, but the reasons are unclear. Dgat1(-/-) mice had reduced mRNA levels of all three Ppar genes and genes involved in fatty acid oxidation in the myocardium of Dgat1(-/-) mice. Although DGAT1 converts DAG to triglycer...
Article
Since 2008, significant advances have been made in understanding the role of diacylglycerol acyl transferase-1 (DGAT1) in disease states such as diabetes and obesity. Gene deletion and overexpression studies have provided important new insights into the function of DGAT1, as have the first reports from preclinical models of small-molecule inhibitor...
Article
Inhibition of DGAT-1 is increasingly seen as an attractive mechanism with the potential for treatment of obesity and other elements of the metabolic syndrome. We report here a bicyclooctaneacetic acid derivative in the pyrimidinooxazine structural class of DGAT-1 inhibitors that has good potency, selectivity, and pharmacokinetic characteristics acr...
Article
Triglyceride (TG) synthesis occurs in many cell-types, but only the adipocyte is specialised for TG storage. The increased incidence of obesity and its attendant pathologies have increased interest in pharmacological strategies aimed at inhibition of triglyceride synthesis. In the liver this would also appear to offer the advantages of the preventi...
Article
Studies in cultured hepatocytes demonstrate glycogen synthase (GS) activation with glycogen phosphorylase (GP) inhibitors. The current study investigated whether these phenomena occurred in vivo using a novel GP inhibitor. An allosteric GP inhibitor, GPi688, was evaluated against both glucagon-mediated hyperglycaemia and oral glucose challenge-medi...
Article
Glycogen phosphorlyase inhibitors (GPi) act on the glycogenolytic pathway decreasing hepatic glucose output, making them potential candidates for Type 2 diabetes treatment. We established a robust in vivo method to assess GPis efficacy utilising glucagon-stimulated glycogenolysis. Blood glucose was monitored in both male AP Wistar and AP Zucker rat...
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Full-text available
The 11beta-hydroxysteroid dehydrogenase type-1 inhibitor BVT.2733 lowers blood glucose and insulin in mutant mouse models of obesity and diabetes. Its effects on energy balance and body composition, and their contribution to improved glucose homeostasis have received little attention. BVT.2733 (100 mg/kg, orally) was given twice daily to lean and d...
Article
Full-text available
The cytokines IL-1 and IL-6 are able to induce prostaglandin (PG)-dependent activation of the hypothalamo-pituitary-adrenal axis (HPAA) and are thought to play key roles in immune-neuroendocrine interactions during inflammation. The present study shows that inflammation induced by im injection of turpentine (TPS) in the hind limb of mice causes an...
Article
Full-text available
Regulation of proopiomelanocortin (POMC) is an important means of controlling the central melanocortin system. It has never been established whether the spectrum of POMC-derived peptides synthesized and secreted from the hypothalamus is altered in response to changes in energy homeostasis in vivo. To monitor secretion, we analyzed peptide content o...
Article
Folliculostellate cells of the anterior pituitary are postulated to be an important source of factors, such as follistatin, that regulate pituitary function by intercellular communication. To gain further insight into the function of this cell type, folliculostellate cells were enriched from cultured rat anterior pituitary cells, and an immortalize...
Article
Folliculostellate cells of the anterior pituitary are postulated to be an important source of factors, such as follistatin, that regulate pituitary function by intercellular communication. To gain further insight into the function of this cell type, folliculostellate cells were enriched from cultured rat anterior pituitary cells, and An immortalize...
Article
The hypothesis that antagonists of the neuropeptide Y5 receptor would provide safe and effective appetite suppressants for the treatment of obesity has prompted vigorous research to identify suitable compounds. We discovered a series of acylated aminocarbazole derivatives (e.g., 3a) that are potent and selective Y5 antagonists, representing interes...
Article
Neuropeptide Y (NPY) is thought to play a key role in stimulating feeding, thus making NPY receptors attractive appetite suppressant drug targets for treating obesity. Because the orexigenic effects of NPY have been ascribed to actions at the NPY Y5 receptor, we have determined the role of this receptor in feeding in rats, using a small molecule an...
Article
Bioactive peptides derived from the prohormone, pro-opiomelanocortin (POMC), are generated in neurons of the hypothalamus and act as endogenous ligands for the melanocortin-4 receptor (MC4R), a key molecule underlying appetite control and energy homeostasis. It is therefore important to understand many aspects of POMC gene regulation in the brain,...
Article
Interleukin (IL)-6 is an important mediator of the host response to disease and has been proposed, largely based upon circumstantial evidence, as the principal endogenous circulating pyrogen responsible for activating CNS mechanisms in fever during infection and inflammation. In the present investigation, we studied the role of peripheral IL-6 in f...
Article
Our understanding of the hypothalamic control of energy homeostasis has increased greatly since the discovery of leptin, the adipose cell derived protein. Recent studies have identified several new hypothalamic neuropeptides that affect food intake and energy balance. By studying these molecules and their neuronal systems, receptors and interaction...
Article
The purpose of this work was to compare the plasma adrenocorticotropin (ACTH), corticosterone and interleukin-6 (IL-6) responses that rats of the outbred Sprague-Dawley strain obtained from two different vendors: Charles River (CR) and Harlan (HSD). Basal plasma ACTH and IL-6 concentrations were similar in rats from either vendor (HSD or CR), while...
Article
Full-text available
Recent studies indicate that the regulation of adrenocorticotropin (ACTH) secretion by corticotropin-releasing factor (CRF) is mediated predominantly by the type I CRF receptor (CRF-R1). Indeed, CRF-R1-deficient (CRF-R1 -/-) mice show marked impairment of the pituitary-adrenal axis. However, the plasma ACTH concentrations of unstressed CRF-R1 -/- m...
Article
Prenatal alcohol exposure has been shown to produce hyperresponsiveness of the hypothalamic-pituitary-adrenal (HPA) axis to immune challenges. Because cytokines, which are released in response to immune challenges, are known to activate the HPA axis, this study determined whether altered release of cytokines contribute to the HPA hyperresponsivenes...
Article
Glucocorticoids are hormone products of the adrenal gland, which have long been recognized to have a profound impact on immunologic processes. The communication between immune and neuroendocrine systems is, however, bidirectional. The endocrine and immune systems share a common "chemical language," with both systems possessing ligands and receptors...
Article
Full-text available
Urocortin (Ucn) is a newly identified mammalian member of the CRF family of peptides. Ucn activates CRF receptors (both CRF-R1 and CRF-R2) with greater potency than CRF itself, suggesting that Ucn may play an endogenous role in eliciting (at least some) CRF receptor-mediated events. Because the most characterized physiological function of CRF recep...
Article
Recent studies indicate that the regulation of adrenocorticotropin (ACTH) secretion by corticotropin-release factor (CRF) is mediated predominantly by the type I CRF receptor (CRF-R1). Indeed, CRF-R1-deficient (CRF-R1 −/−) mice show marked impairment of the pituitary-adrenal axis. However, the plasma ACTH concentrations of unstressed CRF-R1 −/− mic...
Article
Urocortin (Ucn) is a newly identified mammalian member of the CRF family of peptides. Ucn activates CRF receptors (both CRF-R1 and CRF-R2) with greater potency than CRF itself, suggesting that Ucn may play an endogenous role in eliciting (at least some) CRF receptor-mediated events. Because the most characterized physiological function of CRF recep...
Article
We determined whether the gas carbon monoxide (CO) altered the adrenocorticotropin hormone (ACTH) response to mild inescapable electrofootshocks, and whether it interacted with nitric oxide (NO). Peripheral injection of the NO synthase (NOS) inhibitor Nwnitro-L-arginine-methylester (L-NAME), a compound which readily crosses the blood-brain barrier,...
Article
Corticotrophin-releasing factor (CRF) and urocortin possess a high-affinity binding protein. Although the CRF binding protein (BP) can sequester these ligands and inhibit their activity, the endogenous activity of this protein is not understood. Therefore, transgenic mouse lines that over-express the CRF-BP were created. The transgene was construct...
Article
Activins and follistatins regulate all levels of the reproductive axis, including the pituitary where they stimulate and inhibit FSH production, respectively. Gonadotropes are known to express inhibin/activin betaB and activin-B (betaBbetaB) functions as an autocrine modulator of FSH production. By contrast, the mRNA for the activin-binding protein...
Article
Immune stimulation increases the activity of the HPA axis, a phenomenon directly or indirectly mediated through cytokines. We have used two models, the peripheral administration of endotoxin (LPS) or turpentine-induced tissue injury to show that corticotropin-releasing factor (CRF) and vasopressin (VP), hypothalamic peptides released by cytokines,...
Article
Interleukin-6 (IL-6) is a neurotrophic cytokine expressed in both neurons and glia. The present study shows that cerebral ischemia produced by permanent occlusion of the middle cerebral artery (MCAO) produces a dramatic increase in IL-6 bioactivity in the ischemic hemisphere within 2 hours of MCAO (167 +/- 55 IU versus sham: 50 +/- 35 IU), with fur...
Article
The present study tested the hypothesis that the cytokine tumor necrosis factor-alpha (TNF-alpha) is an important central nervous system mediator of the rat hypothalamo-pituitary-adrenal (HPA) axis response to the i.v. administration of lipopolysaccharide (LPS; 5 microg/kg). LPS produced a rapid (within 30 min) rise in plasma TNF-alpha levels, whic...
Article
The findings of the preceding article suggest that intracerebroventricular (i.c.v.) administration of small amounts (5 microl) of antisera to rats may produce effectual immunoneutralization of peptides in blood/tissues outside of the central nervous system (CNS). In the present work we sought to test this hypothesis by determining the titers of cor...
Article
The present study tested the hypothesis that the cytokine tumor necrosis factor-α (TNF-α) is an important central nervous system mediator of the rat hypothalamo-pituitary-adrenal (HPA) axis response to the iv administration of lipopolysaccharide (LPS; 5 μg/kg). LPS produced a rapid (within 30 min) rise in plasma TNF-α levels, which preceded elevati...
Article
The findings of the preceding article suggest that intracerebroventricular (icv) administration of small amounts (5 μl) of antisera to rats may produce effectual immunoneutralization of peptides in blood/tissues outside of the central nervous system (CNS). In the present work we sought to test this hypothesis by determining the titers of correspond...
Article
Corticotropin-releasing factor (CRF) is a 41-amino acid neuropeptide, which is recognized as a critical mediator of complimentary, stress-related endocrine, autonomic, and behavioral responses in mammalian species. CRF belongs to a family of structurally related peptides including frogskin sauvagine and fish urotensin I. The effects of CRF and rela...
Article
Full-text available
The present study tested the hypothesis that the cytokine tumor necrosis factor-alpha (TNF-alpha) is an important CNS mediator of the hypothalamo-pituitary-adrenal (HPA) axis response to local inflammation in the rat. Recombinant murine TNF-alpha administered directly into the cerebroventricles of normal rats produced a dose-dependent increase in p...
Article
Bacterial endotoxins produce profound activation of the hypothalamo-pituitary-adrenal axis, mediated by stimulation of hypothalamic CRF neurons. Although a number of studies have described direct pituitary actions of inflammatory mediators, the effects of inflammatory stimuli on the sensitivity of corticotropes to CRF remain to be elucidated. The a...
Article
We investigated the role and interaction between tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and IL-6 in the development of fever and their involvement in brain and systemic pathways in response to localized tissue inflammation caused by injection of turpentine (TPS) in the rat. Intramuscular injection of 10 microl TPS caused significant...
Article
The intracerebroventricular (icv) injection of the proinflammatory cytokineinterleukin(IL)-1bisknowntosignificantlydecreaseplasma LH levels in the male rat, thereby lowering testosterone (T) secretion. We show here that central administration of this cytokine (20-80 ng) also inhibits T secretion in response to human CG (hCG), an effect that is appa...
Article
The intracerebroventricular (icv) injection of the proinflammatory cytokine interleukin (IL)-1β is known to significantly decrease plasma LH levels in the male rat, thereby lowering testosterone (T) secretion. We show here that central administration of this cytokine (20–80 ng) also inhibits T secretion in response to human CG (hCG), an effect that...
Article
Nitric oxide synthase (NOS) exists in at least three distinct isoforms: an inducible NOS (NOS II), and two forms which are constitutively expressed-brain NOS (NOS I) and endothelial NOS (NOS III). We have previously shown that the NOS inhibitor, N(ω)-nitro-L-arginine methyl ester hydrochloride (L-NAME), markedly potentiates and prolongs the increas...
Article
Urocortin is a recently characterized mammalian peptide which appears to be an endogenous ligand for corticotropin-releasing factor (CRF) receptors, in particular CRF receptor type 2. The effect of rat urocortin on protein extravasation and edema, produced by immersion of the paws of anesthetized rats in 58 degrees C water for 5 min, was compared t...
Article
Infectious, malignant, and inflammatory diseases are associated with marked increases in the expression of a class of immunoregulators, known as cytokines, that are thought to mediate the accompanying endocrine responses, This paper reviews the effects of administered cytokines on neuroendocrine secretory activity in otherwise healthy animals and h...
Article
The present study determined the plasma ACTH and corticosterone responses of the rat to acute local inflammation induced by the im injection of a small volume of turpentine. In response to tissue injury, ACTH and corticosterone concentrations rose rapidly, peaked at 1 h, and returned toward basal values by 3 h after turpentine injection. As acute i...
Article
The present study determined the plasma ACTH and corticosterone responses of the rat to acute local inflammation induced by the im injection of a small volume of turpentine. In response to tissue injury, ACTH and corticosterone concentrations rose rapidly, peaked at 1 h, and returned toward basal values by 3 h after turpentine injection. As acute i...
Article
Cytokines are a group of polypeptide mediators, classically associated with the regulation of immunity and inflammation. However, these peptides regulate not only local immune/inflammatory responses, but also elicit many CNS-mediated responses which accompany such immune/inflammatory reactions. This article reviews the evidence that interleukin (IL...
Chapter
The existence of bilateral communication between the immune and neuroendocrine systems is now well established. The products of the neuroendocrine system, hormones such as corticosteroids, prolactin and growth hormone, have pronounced effects on a variety of aspects of immunoregulation, including T lymphocyte selection, splenic lymphocyte release a...
Article
Full-text available
CORTICOTROPIN-RELEASING factor (CRF), a peptide first isolated from mammalian brain1, is critical in the regulation of the pituitary–adrenal axis, and in complementary stress-related endocrine, autonomic and behavioural responses2. Fish urotensin I and amphibian sauvagine were considered to be homologues3 of CRF until peptides even more closely rel...
Article
The immune system and several endocrine axes communicate with each other through a network of molecules which collectively produce a coordinated response to immune challenges. This phenomenon, necessary for the survival of the organism, is thought to involve the release, by activated cells in the periphery, of proteins, called cytokines, which info...
Article
The involvement of endogenous tumor necrosis factor-alpha (TNF-alpha) in the pyrogenic [i.e., rise in colonic temperature (Tc)] and thermogenic [increase in oxygen consumption (VO2)] responses to inflammation was investigated in rats subjected to an intramuscular injection of turpentine. Turpentine administration caused a rise in Tc and VO2 within...
Article
To characterize the mechanisms of the pituitary-adrenal (P-A) response to tissue injury, rats were injected intramuscularly (IM) with turpentine. This resulted in marked elevations in the plasma concentrations of ACTH and corticosterone within the first hour after injection, which were attenuated by either total deafferentation of the medial basal...
Article
Full-text available
Modification of endogenous eicosanoid synthesis by dietary n-3 fatty acid supplementation reduces febrile responses, but the mechanisms underlying these effects in vivo have not been determined. In the present study, local inflammation was induced by intramuscular injection ofturpentine in rats fed control or n-3 supplemented diets for 8-9 weeks. I...
Article
1. The effects of bilateral hindlimb ischaemia (BHLI), and of administration of the neuropeptide corticotrophin-releasing factor (CRF), were tested on cardiovascular variables in propofol-anaesthetized Sprague-Dawley rats. In addition, the effects of antagonizing endogenous CRF on the cardiovascular response to BHLI was investigated. 2. BHLI produc...
Chapter
An intriguing feature of trauma research is that changes can be found in any system investigated. Thus plasma concentrations of many hormones, enzymes, substrates and metabolites rise and/or fall, and indices of organ and tissue function change without any obviously discernable overall pattern. This has led to a plethora of studies of such changes...

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