Contabilidad de costes basada en la actividad es de un Servicio de Neurofisiología Clínica / Cost accounting based on the activities of a Clinical Neurophysiological Service

Se ha realizado una aproximación al coste de cada producto de la cartera de servicios del Servicio de Neuro fisiología Clínica del Hospital Regional Universitario Carlos Haya de Malaga, para un periodo annual, con el fin de disponer de informació detallada para la autogestión del presupuesto de dicho Servicio. El estudio se compone de dos etapas: la primera, centrada en la definición de las Unidades Relativas de Valor de las actividades de los Servicios de Neurofisiología Clínica de la Comunidad Autónoma de Andalcía; y la segunda, expuesta en este trabajo, calcula el cose por Unidad Relativa de Valor y determina los precios de los productos ofertados por el Servicio de Neurofisiología Clínica de nuestro cenro. El propósito de este trabajo es poner de manifiesto una forma de valorar las actividades desarroladas por un Servicio de Neurofisiología Clínica y sus concluisones para debatir sobre la autogestión de estos Servicios, cuestión cada vez de mayor actualidad (AU)

The purpose of this work is to highlight a way to value the activities developed for a Clinical Neurophysiological Service and its conclusions in order to debate about the self-management of these services (AU)

Estudio económico sobre el coste ocasionado por la utilización de placas radiográficas en radiología / No disponible

El motivo del presente trabajo es el de presentar una metodología básica, pero muy completa para el cálculo del coste de una placa radiográfica clásica, así como la presentación de otras consideraciones sobre el medio ambiente que tiene el uso de esa tecnología, de forma que cualquier hospital o clínica pueda adaptarlo a sus sistemas y poder decidir con base, si conviene evolucionar a otras tecnologías de tratamiento de imagen. Como base para presentar este modelo, hemos optado por usar un estudio real, realizado en el año 2002 en el Hospital Regional Universitario de Málaga. Para obtener el coste total ocasionado por el consumo de placas en Radiodiagnóstico, se ha contado con: El consumo real de placas. El consumo de fijador. El consumo de revelador. El coste de mantenimiento de las máquinas reveladoras. El coste de la energía eléctrica consumida por las máquinas reveladoras tanto en espera como en funcionamiento. El coste del agua consumida por las máquinas reveladoras. Todo referido a los gastos y consumos desde el 1 de enero al 31 de diciembre del año 2002 en el Hospital Regional Universitario Carlos Haya de Málaga, comprendido por los siguientes centros: Hospital Civil (incluido el Centro de Especialidades) Hospital Ciudad Jardín. Hospital General. Hospital Materno Infantil (AU)

No disponible

Acercamiento asequible al cálculo de costes por procedimiento de un servicio. (El ejemplo de cirugía torácica) / An easy-to-understand approach to cost calculation per procedure in a health service (with the example of the Thoracic Surgery service)

Se presenta un sistema que permita, con los instrumentos existentes en cualquier hospital, conocer y controlar los costes originados por los procedimientos realizados en un servicio asistencial, a un nivel más detallado que el de los GRD. Para la realización de este trabajo se ha escogido el servicio de Cirugía torácica del Hospital Regional Universitario de Málaga. Los datos necesarios se han de obtener del sistema de costes del Hospital, en nuestro caso el COAN-HyD1 y del CMBD una vez agrupado por GRD: 1. Los datos de costes se usan a niel del área de Hospitalización del servicio que corresponda en el periodo de estudio 2. Los datos del CMBD sean de procesar de la forma que se explica en el artículo para obtener los procedimientos en los que partir el coste antedicho. 3. Este reparto se hace relacionando las variables de estancias, costes y porcentajes de codificación de forma que obtengamos como resultado final el coste de cada uno de los procedimientos del servicio (AU)

This article presents a system which, using the normal management tools of a hospital, makes it possible to know and control the costs originated by the procedures carried out in a health service, in greater detail that with the DRG system (Diagnosis Relational Groups). The Thoracic Surgery service of the Hospital Regional Universitario of Malaga was chosen in order to carry out this work (AU)

L-750355, a human beta3-adrenoceptor agonist; in vitro pharmacology and profile of activity in vivo in the rhesus monkey.

The profile of in vitro and in vivo biology of a human beta3-adrenoceptor agonist, (S)-N-[4-[2-[[3[(2-amino-5-pyridinyl)oxy]-2-hydroxy-propyl]amino]-eth yl]-phenyl]-4-isopropylbenzenesulfonamide, L-750355, is described. Using cloned human and rhesus beta1-, beta2- and beta3-adrenoceptors, expressed in Chinese hamster ovary (CHO) cells, L-750355 was shown to be a potent, albeit partial, agonist for the human (EC(50)=10 nM; % maximal receptor activation=49%) and rhesus (EC(50)=28 nM; % maximal receptor activation=34%) beta3-adrenoceptors. Furthermore, L-750355 stimulates lipolysis in rhesus adipocytes in vitro. L-750355 is a weak partial agonist (EC(50)=3.2 microM; % maximal receptor activation=33% ) for the human beta1-adrenoceptor but exhibits no agonist activity for rhesus beta1- or beta2-adrenoceptors of either human or rhesus origin. Administration of L-750355 to anesthetized rhesus monkeys, as a series of rising dose intravenous infusions, evokes dose-dependent glycerolemia and tachycardia with no change in mean arterial blood pressure or plasma potassium. The dose-response curve for L-750355-induced glycerolemia lies to the left of that for tachycardia. Propranolol, at a dose (0.3 mg/kg, i.v. ) that attenuates isoproterenol-induced changes in heart rate and glycerolemia, abolished L-750355-induced tachycardia but had no effect on L-750355-induced glycerolemia.

Characterization of a novel, non-peptidyl antagonist of the human glucagon receptor.

We have identified a series of potent, orally bioavailable, non-peptidyl, triarylimidazole and triarylpyrrole glucagon receptor antagonists. 2-(4-Pyridyl)-5-(4-chlorophenyl)-3-(5-bromo-2-propyloxyphenyl)p yrr ole (L-168,049), a prototypical member of this series, inhibits binding of labeled glucagon to the human glucagon receptor with an IC50 = 3. 7 +/- 3.4 nM (n = 7) but does not inhibit binding of labeled glucagon-like peptide to the highly homologous human glucagon-like peptide receptor at concentrations up to 10 microM. The binding affinity of L-168,049 for the human glucagon receptor is decreased 24-fold by the inclusion of divalent cations (5 mM). L-168,049 increases the apparent EC50 for glucagon stimulation of adenylyl cyclase in Chinese hamster ovary cells expressing the human glucagon receptor and decreases the maximal glucagon stimulation observed, with a Kb (concentration of antagonist that shifts the agonist dose-response 2-fold) of 25 nM. These data suggest that L-168,049 is a noncompetitive antagonist of glucagon action. Inclusion of L-168, 049 increases the rate of dissociation of labeled glucagon from the receptor 4-fold, confirming that the compound is a noncompetitive glucagon antagonist. In addition, we have identified two putative transmembrane domain residues, phenylalanine 184 in transmembrane domain 2 and tyrosine 239 in transmembrane domain 3, for which substitution by alanine reduces the affinity of L-168,049 46- and 4. 5-fold, respectively. These mutations do not alter the binding of labeled glucagon, suggesting that the binding sites for glucagon and L-168,049 are distinct.

Peroxisome proliferator-activated receptors gamma and alpha mediate in vivo regulation of uncoupling protein (UCP-1, UCP-2, UCP-3) gene expression.

A role for peroxisome proliferator-activated receptors, PPAR gamma and PPAR alpha, as regulators of energy homeostasis and lipid metabolism, has been suggested. Recently, three distinct uncoupling protein isoforms, UCP-1, UCP-2, and UCP-3, have also been identified and implicated as mediators of thermogenesis. Here, we examined whether in vivo PPAR gamma or PPAR alpha activation regulates the expression of all three UCP isoforms. Rats or lean and db/db mice were treated with PPAR gamma [thiazolidinedione (TZD)] or PPAR alpha (WY-14643) agonists, followed by measurement of messenger RNAs (mRNAs) for UCP-1, UCP-2, and UCP-3 in selected tissues where they are expressed. TZD treatment (AD 5075 at 5 mg/kg x day) of rats (14 days) increased brown adipose tissue (BAT) depot size and induced the expression of each UCP mRNA (3x control levels for UCP-1 and UCP-2, 2.5x control for UCP-3). In contrast, UCP-2 and UCP-3 mRNA levels were not affected in white adipose tissue or skeletal muscle. Chronic (30 days) low-dose (0.3 mg/kg x day) TZD treatment induced UCP-1 mRNA and protein in BAT (2.5x control). In contrast, chronic TZD treatment (30 mg/kg x day) suppressed UCP-1 mRNA (>80%) and protein (50%) expression in BAT. This was associated with further induction of UCP-2 expression (>10-fold) and an increase in the size of lipid vacuoles, a decrease in the number of lipid vacuoles in each adipocyte, and an increase in the size of the adipocytes. TZD treatment of db/db mice (BRL 49653 at 10 mg/kg x day for 10 days) also induced UCP-1 and UCP-3 (but not UCP-2) expression in BAT. PPAR alpha is present in BAT, as well as liver. Treatment of rats or db/db mice with WY-14643 did not affect expression of UCP-1, -2, or -3 in BAT. Hepatic UCP-2 mRNA was increased (4x control level) in db/db and lean mice, although this effect was not observed in rats. Thus, in vivo PPAR gamma activation can induce expression of UCP-1, -2, and -3 in BAT; whereas chronic-intense PPAR gamma activation may cause BAT to assume white adipose tissue-like phenotype with increased UCP-2 levels. PPAR alpha activation in mice is sufficient to induce liver UCP-2 expression.

Desensitization of beta3-adrenergic receptor-stimulated adenylyl cyclase activity and lipolysis in rats.

The beta3-adrenergic receptor is an integral membrane protein consisting of seven transmembrane domains. Unlike the beta1 and beta2 receptors, this subtype lacks the consensus phosphorylation sites required for desensitization by serine kinases. Using the rodent specific beta3 agonist BRL 35135, our initial data indicated that beta3 receptor-mediated glycerol levels progressively decreased following daily oral doses of 5 mg/kg. Therefore, we initiated studies designed to delineate the possible mechanism(s) for this decreased response. Within 3 hours following a single oral dose of BRL 35135, serum glycerol levels and UCP (uncoupling protein) RNA levels were significantly increased whereas beta3 RNA levels were significantly decreased. Rats were dosed daily for 5 days with either vehicle or BRL 35135 (5 mg/kg, p.o.) and blood samples were collected for glycerol analysis. Adipose tissue was excised for lipolysis and adenyl cyclase measurements. In addition, UCP and beta3 receptor RNA levels were assessed. No effect on adipocyte BRL 37344-stimulated adenylyl cyclase activity was observed 3 hours following the initial dose of BRL 35135. Although a slight decrease (approximately 25%) in adenylyl cyclase activity could be observed 24 hours following the initial dose, it wasn't until day 4 of dosing that a significant decrease (50%) was observed. In contrast, beta3- stimulated lipolysis in adipocytes from BRL 35135-treated rats was decreased 85% within 24 hours and this decrease persisted through four days of treatment. These data indicate that the lipolytic response to beta3 receptor activation is decreased after only a single oral dose of BRL 35135, whereas receptor-mediated adenylyl cyclase activation, although initially unaffected, also desensitizes by day four of treatment.

Alterations in receptor activation and divalent cation activation of agonist binding by deletion of intracellular domains of the glucagon receptor.

Deletion of residues 252-259 within the putative second intracellular loop of the human glucagon receptor results in a protein with high affinity for glucagon but with attenuated agonist activation of adenylyl cyclase. The Delta252-259 mutant has 4-fold higher affinity for glucagon than does the wild type receptor. The nonhydrolyzable GTP analog, guanosine 5'-(beta, gamma-imido)triphosphate (Gpp(NH)p), inhibits binding of 125I-glucagon to the wild type receptor but not to the Delta252-259 mutant. Divalent cations such as MgCl2 and CaCl2 stimulate the binding of 125I-glucagon to the wild type receptor by increasing glucagon affinity. The rate of dissociation of 125I-glucagon is decreased 4-fold by MgCl2 and increased 6-fold by Gpp(NH)p. However, divalent cations do not affect the binding of 125I-glucagon to the Delta252-259 mutant. The rate of dissociation of 125I-glucagon from the Delta252-259 mutant protein is equivalent to the rate of dissociation from the wild type receptor in the presence of MgCl2. These data suggest that at least three conformations of the glucagon receptor can exist in the membrane based on their differing affinities for 125I-glucagon. Deletion of residues 252-259 appears to lock the protein in the conformation promoted by divalent cations and prevents the protein from normal coupling to Gs.

Identification of residues involved in ligand binding to the neurokinin-2 receptor.

Several residues of the human neurokinin-2 receptor have been identified to be critical for the binding of peptide agonists and non-peptide antagonists. Amino acid substitutions in the first and second extracellular segments and the second transmembrane segment led to substantial reduction in peptide affinity without affecting the affinity of antagonist SR48968. These effects are identical to those observed for homologous residues in the neurokinin-1 receptor, suggesting that these three regions are involved in high-affinity peptide binding to both receptor subtypes. On the other hand, some conserved residues in the fourth to seventh transmembrane segments are required for peptide binding to only one receptor subtype but not both. The conserved nature and location of these receptor residues suggest that the distance between bound peptide and helices 4-7 varies depending on the receptor subtype. It is likely that the conformational compatibility between a ligand and a given receptor determines the magnitude of binding affinity, and thus receptor subtype selectivity. While many single-residue substitutions did not affect the binding affinity of the antagonist SR48968, two double mutants in the sixth and seventh transmembrane segments were found to reduce its affinity substantially. Therefore, receptor residues participate cooperatively in the binding of SR48968. These results demonstrate the usefulness of combining single-residue substitutions in studying and confirming the role of receptor residues in ligand binding. Finally, the overlapping nature of agonist and antagonist binding sites is consistent with the observation that substitutions of some residues modify the binding affinities of both peptide agonists and non-peptide antagonists.

Synthesis and hypoglycemic activity of substituted 8-(1-piperazinyl)imidazo[1,2-a]pyrazines.

A series of alkyl- and halo-substituted 8-(1-piperazinyl)imidazo[1,2-a]pyrazines were prepared using two approaches, the condensation of alpha-halocarbonyl derivatives with an aminopyrazine or the oxidation-dehydration of a [(beta-hydroxyalkyl)amino]pyrazine. These imidazo[1,2-a]pyrazines were evaluated for their binding affinity to the alpha 1, alpha 2, beta 1, and beta 2 adrenergic receptors as well as their ability to lower blood glucose in insulin resistant hyperglycemic ob/ob mice. Modifications on 8-(1-piperazinyl)imidazo[1,2-a]pyrazine (4) reduced alpha 2 binding, lowered hypoglycemic potency, and showed variations in binding to the alpha 1, beta 1, and beta 2 adrenergic receptors. In addition to 4, the 2-methyl, 3-methyl, and 5-methyl 8-(1-piperazinyl)imidazo[1,2-a]pyrazines (16k, 25m, and 16f, respectively) displayed high affinity for the alpha 2 receptor and were potent hypoglycemic agents when compared to 2-amino-7,8-dihydro-4-(1-piperazinyl)-6H-thiopyrano[3,2- d]pyrimidine (MTP-1403, 2). Receptor binding was modified by use of a 4-methylpiperazine moiety which reduced alpha 1 and beta 1 binding while retaining some hypoglycemic activity. The structure-activity relationship for heterocyclic alkyl and halo substitution on biological activity is discussed.

The function but not the expression of rat liver inhibitory guanine nucleotide binding protein is altered in streptozotocin-induced diabetes.

Adenylate cyclase activity was examined as a measure of inhibitory guanine nucleotide binding protein (Gi) function in liver plasma membranes from rats made chemically diabetic by streptozotocin (STZ) treatment. Clonidine activation of the alpha 2 adrenergic receptor, which activates Gi, inhibited forskolin--stimulated adenylate cyclase activity in control membranes. However, there was no effect on adenylate cyclase activity in membranes from STZ diabetic animals. Also, a polyclonal antipeptide antibody was raised to a highly conserved segment of the Gi alpha 2 subunit. This antibody specifically recognizes a 41 kilodalton protein, is blocked by an excess of peptide, does not recognize the alpha-subunit of transducin, and immunoprecipitates a 41 kilodalton protein which was ADP-ribosylated by pertussis toxin. Immunoblots using this antibody detect no difference between normal and STZ diabetic animals in the level of liver plasma membrane Gi expression. Therefore, STZ-induced diabetes altered the function of Gi but had no effect on Gi expression.

Vanadate treatment of streptozotocin diabetic rats restores expression of the insulin-responsive glucose transporter in skeletal muscle.

Streptozotocin-treated rats were diabetic, as assessed by blood glucose and plasma insulin values, while vanadate treatment restored blood glucose values to normal. Immunoblot analysis using a monoclonal antibody to the insulin-responsive glucose transporter demonstrated a 70% decline in transporter expression in skeletal muscle of diabetic rats. Subsequent treatment of diabetic animals with vanadate resulted in renewed expression of the transporter to 87% of control levels. Northern blot analysis of total skeletal muscle RNA from diabetic animals revealed a 55% decline in the steady state level of muscle glucose transporter mRNA, while vanadate treatment led to a 187% increase in transporter mRNA over normal levels. These results support the conclusion that vanadate acts to relieve diabetic hyperglycemia by inducing expression of the insulin-responsive glucose transporter at the pretranslational level.

Separate effects of Mg2+, MgATP, and ATP4- on the kinetic mechanism for insulin receptor tyrosine kinase.

The separate effects of the equilibrium species Mg2+, MgATP substrate, and ATP4- on the reaction catalyzed by insulin receptor tyrosine kinase were examined. The separated kinetic constants show that the K0.5 value for Mg2+ decreased from 23 to 0.43 mM and the Hill coefficient for Mg2+ (hMg2+) decreased from 1.43 to 0.668 when the concentration of ATPT (MgATP + ATP4-) was increased from 50 to 1000 microM. The apparent Ki for ATP4- increased from 0.20 to 136 microM and the Hill coefficient for ATP4- (hATP4-) decreased from 1.41 to 0.82 as the concentration of total ATP (ATPT) increased. These findings suggest that the [ATP4-]/[Mg2+] ratio modulates the shift from positive to negative cooperativity. It was also shown that the apparent affinity of the kinase for MgATP increased as the concentration of free Mg2+ increased and that the apparent affinity of the kinase for free Mg2+ increased as the concentration of MgATP substrate increased. Thus, Mg2+ and MgATP interact with the kinase in a mutually inclusive manner which leads to an increase in the ratio of the enzyme (E) rate-limiting species, [Mg-E-MgATP]/[E-MgATP]. Free ATP4- not only acts as a competitive inhibitor of the substrate but also decreases the relative concentration of Mg-E-MgATP. ATPT-dependent activation of the kinase is, therefore, a result of MgATP's increasing the affinity of the kinase for Mg2+, thereby leading to saturation of the enzyme with Mg2+ at lower concentrations of the divalent metal. This results in an increase in the [Mg-E-MgATP]/[E-MgATP] ratio, and therefore decreases saturation of the kinase with ATP4- inhibitor, not only at the active site but also at a kinetically distinct regulatory site. This kinetic relationship allows not only for the mutually inclusive interaction between Mg2+ and MgATP, but also for the mutually exclusive interaction toward ATP4-, hence indicating that the effect of Mg2+ will be to form an enzyme complex (Mg-E) which will have a higher affinity for MgATP substrate and a lower affinity for ATP4- than E alone. The role of the equilibrium concentrations of Mg-E,E, and ATP-E on the activation of insulin receptor tyrosine kinase is discussed which may account, at least in part, for modulation of cooperativity and the metal-dependent increase in turnover (VM).

The effect of ponalrestat on sorbitol levels in the lens of obese and diabetic mice.

Sorbitol levels were determined in lens of genetically obese (ob/ob) and diabetic (db/db) mice, as well as in lean mice (+/db, +/ob) made diabetic by administration of streptozotocin (STZ). Treatment of lean mice with STZ resulted in hypoinsulinemia, whereas the ob/ob and db/db mice were hyperinsulinemic. Hyperglycemia was present in STZ-treated +/db and +/ob mice and in db/db mice, whereas relative euglycemia was observed in ob/ob mice and untreated +/db and +/ob mice. Sorbitol levels were elevated in lens tissue of db/db mice and STZ-treated +/db. In contrast, no changes in sorbitol content were observed in ob/ob mice and +/ob mice treated with STZ, suggesting that aldose reductase activity in lens of this animal model is considerably less than that present in db/db mice. Oral treatment of db/db mice and STZ-treated +/db mice with Ponalrestat reduced hyperglycemia-induced sorbitol accumulation significantly in lens, indicating that aldose reductase inhibitors may ameliorate long-term complications associated with sorbitol accumulation in diabetes.

Decreased expression of the insulin-responsive glucose transporter in diabetes and fasting.

Cellular resistance to insulin caused by a reduction in insulin-mediated glucose uptake can be produced in rats by chemically inducing diabetes with streptozotocin and by fasting. Two glucose transporter isoforms are expressed in fat cells: (1) the insulin-responsive species which is found only in fat and muscle, and (2) a species corresponding to the erythrocyte/Hep G2/rat brain transporter. We show here that fat cells isolated from streptozotocin diabetic rats and from fasted rats show a significant (60-80%) decrease in the amount of immunologically detectable insulin-sensitive glucose transporter and no change in the level of the Hep G2/rat brain transporter. Administration of insulin and refeeding, respectively, result in a return of the insulin-sensitive glucose transporter to levels that are normal or slightly above normal. Thus, peripheral tissue insulin resistance could be due to the specific reduction in the amount of insulin-sensitive glucose transporter.

Impaired insulin-like growth factor I-mediated stimulation of glucose incorporation into glycogen in vivo in the ob/ob mouse.

The ability of insulin to modulate glucose metabolism is impaired in insulin resistant ob/ob mice. It has been shown that insulin-like growth factor I stimulates the uptake and metabolism of glucose in muscle through the insulin-like growth factor receptor not the insulin receptor. Thus, we have compared the abilities of insulin-like growth factor I and insulin to stimulate the in vivo incorporation of [14C]-glucose into glycogen in the diaphragm of ob/ob mice and their lean littermates. The animals used in these studies were 12-14 weeks old and the serum insulin levels of the ob/ob mice were 16-fold higher than in their lean littermates. There were no differences in the serum levels of glucose or insulin-like growth factor I. Both insulin and insulin-like growth factor I stimulate the incorporation of [14C]-glucose into glycogen in lean mice. Significant stimulation occurs at doses as low as 1 micrograms/kg of either peptide. The effective doses of insulin and insulin-like growth factor I are quite similar, which indicates that the effect of insulin-like growth factor I is mediated by the insulin-like growth factor receptor and not the insulin receptor. In contrast, greater than 100 micrograms/kg of insulin-like growth factor I is required to stimulate [14C]-glucose incorporation into glycogen in the diaphragm of ob/ob mice. Thus, ob/ob mice are resistant to the action of both insulin and insulin-like growth factor I.(ABSTRACT TRUNCATED AT 250 WORDS)

Design of a selective insulin receptor tyrosine kinase inhibitor and its effect on glucose uptake and metabolism in intact cells.

An inhibitor of the insulin receptor tyrosine kinase (IRTK), (hydroxy-2-naphthalenyl-methyl) phosphonic acid, was designed and synthesized and was shown to be an inhibitor of the biological effects of insulin in vitro. With a wheat germ purified human placental insulin receptor preparation, this compound inhibited the insulin-stimulated autophosphorylation of the 95-kDa beta-subunit of the insulin receptor (IC50 = 200 microM). The ability of the kinase to phosphorylate an exogenous peptide substrate, angiotensin II, was also inhibited. Half-maximal inhibition of basal and insulin-stimulated human placental IRTK activity was found at concentrations of 150 and 100 microM, respectively, with 2 mM angiotensin II as the peptide substrate. The inhibitor was found to be specific for tyrosine kinases over serine kinases and noncompetitive with ATP. The inhibitor was converted into various (acyloxy)methyl prodrugs in order to achieve permeability through cell membranes. These prodrugs inhibited insulin-stimulated autophosphorylation of the insulin receptor 95-kDa beta-subunit in intact CHO cells transfected with human insulin receptor. Inhibition of insulin-stimulated glucose oxidation in isolated rat adipocytes and 2-deoxyglucose uptake into CHO cells was observed with these prodrugs. Our data provide additional evidence for the involvement of the insulin receptor tyrosine kinase in the regulation of glucose uptake and metabolism. These results and additional data reported herein suggest that this class of prodrugs and inhibitors will be useful for modulating the activity of a variety of tyrosine kinases.

The insulin-mimetic effect of vanadate is not correlated with insulin receptor tyrosine kinase activity nor phosphorylation in mouse diaphragm in vivo.

The in vivo administration of sodium orthovanadate stimulated the incorporation of [14C]glucose into [14C] glycogen, in a dose- and time-dependent manner, in mouse diaphragm. Activation of diaphragm insulin receptor was measured by exogenous tyrosine kinase activity and an antibody that recognizes a conformational change in the receptor beta-subunit upon autophosphorylation. Neither method detected insulin receptor activation by in vivo vanadate administration, suggesting that vanadate's insulin-mimetic effect on mouse diaphragm glycogenesis occurs at a site distal to the insulin receptor.