Protein Intake during Weight Loss Influences the Energy Required for Weight Loss and Maintenance in Cats

The effects of 2 diets with different protein contents on weight loss and subsequent maintenance was assessed in obese cats. The control group [Cc; n = 8; body condition score (BCS) = 8.6 +/- 0.2] received a diet containing 21.4 g crude protein (CP)/MJ of metabolizable energy and the high-protein group (HP; n = 7; BCS = 8.6 +/- 0.2) received a diet containing 28.4 g CP/MJ until the cats achieved a 20% controlled weight loss (0.92 +/- 0.2%/wk). After the weight loss, the cats were all fed a diet containing 28.0 g CP/MJ at an amount sufficient to maintain a constant body weight (MAIN) for 120 d. During weight loss, there was a reduction of lean mass in Cc (P < 0.01) but not in HIP cats and a reduction in leptinemia in both groups (P < 0.01). Energy intake per kilogram of metabolic weight (kg(-0.40)) to maintain the same rate of weight loss was lower (P < 0.04) in the Co (344 +/- 15.9 kJ.kg(-0.40).d(-1)) than in the HP group (377 +/- 12.4 kJ.kg-(0.40).d(-1)). During the first 40 d of MAIN, the energy requirement for weight maintenance was 398.7 +/- 9.7 kJ.kg(-0.40).d(-1) for both groups, corresponding to 73% of the NRC recommendation. The required energy gradually increased in both groups (P < 0.05) but at a faster rate in HP; therefore, the energy consumption during the last 40 d of the MAIN was higher (P < 0.001) for the HP cats (533.8 +/- 7.4 kJ.kg(-0.40).d(-1)) than for the control cats (462.3 +/- 9.6 kJ.kg(-0.40).d(-1)). These findings suggest that HIP diets allow a higher energy intake to weight loss in cats, reducing the intensity of energy restriction. Protein intake also seemed to have long-term effects so that weight maintenance required more energy after weight loss. J. Nutr, 139: 855-860, 2009.

Error in body weight estimation leads to inadequate parenteral anticoagulation

Parenteral anticoagulation is a cornerstone in the management of venous and arterial thrombosis. Unfractionated heparin has a wide dose/response relationship, requiring frequent and troublesome laboratorial follow-up. Because of all these factors, low-molecular-weight heparin use has been increasing. Inadequate dosage has been pointed out as a potential problem because the use of subjectively estimated weight instead of real measured weight is common practice in the emergency department (ED). To evaluate the impact of inadequate weight estimation on enoxaparin dosage, we investigated the adequacy of anticoagulation of patients in a tertiary ED where subjective weight estimation is common practice. We obtained the estimated, informed, and measured weight of 28 patients in need of parenteral anticoagulation. Basal and steady-state (after the second subcutaneous shot of enoxaparin) anti-Xa activity was obtained as a measure of adequate anticoagulation. The patients were divided into 2 groups according the anticoagulation adequacy. From the 28 patients enrolled, 75% (group 1, n = 21) received at least 0.9 mg/kg per dose BID and 25% (group 2, n = 7) received less than 0.9 mg/kg per dose BID of enoxaparin. Only 4 (14.3%) of all patients had anti-Xa activity less than the inferior limit of the therapeutic range (<0.5 UI/mL), all of them from group 2. In conclusion, when weight estimation was used to determine the enoxaparin dosage, 25% of the patients were inadequately anticoagulated (anti-Xa activity <0.5 UI/mL) during the initial crucial phase of treatment. (C) 2011 Elsevier Inc. All rights reserved.

Short-Term Carbohydrate-Restricted Diet for Weight Loss in Severely Obese Women

Weight loss in bariatric pre-surgery period reduces surgical complications, surgery time, blood loss, and length of hospital stay. Carbohydrate-restricted diets have been used as an alternative for weight loss. We tested the efficacy of a low-calorie carbohydrate-restricted diet (RD) for short-term weight loss in women with severe obesity and evaluate its metabolic effects in relation to a conventional low-calorie diet (CD). The subjects received a 1,200-kcal diet with or without carbohydrate restriction for a period of 1 week in the hospital. Nineteen obesity class III women were distributed into two groups: experimental (n = 10) and control (n = 9). The following variables were assessed at the beginning and end of the study: anthropometric measurements, body composition, resting energy expenditure, substrate oxidation, and biochemical tests. Compared with CD, RD led to larger weight loss (2.6 and 4.4 kg, respectively; p = 0.01) and waist circumference reduction (p < 0.01). Among the assessed biochemical indicators, only plasma and urine acetone levels were different (p < 0.01); higher values were found in the experimental group with no symptoms and other diet-related complaints. There was also a significant decrease in triglycerides and carbohydrate oxidation, as well as a significant enhancement in lipid oxidation in the RD group. Short-term RD was more efficient than CD regarding quick weight loss and waist circumference reduction, which may favor gastroplasty. Also, RD did not lead adverse metabolic effects.

Diagonal band of Broca modulates the cardiac component of the baroreflex in unanesthetized rats

The diagonal band of Broca (DBB) is involved in cardiovascular control in rats, In the present Study, we report the effect of acute and reversible neurotransmission inhibition in the DBB by bilateral microinjection of the nonselective neurotransmission blocker CoCl(2) (1 mM, 100 nL) on the cardiac baroreflex response in unanesthetized rats. Local DBB neurotransmission inhibition did not affect baseline values of either blood pressure or heart rate, Suggesting no tonic DBB influence oil cardiovascular system activity. However, CoCl(2) microinjections enhanced both the reflex bradycardia associated with blood pressure increases caused by i.v. infusion of phenylephrine and tachycardiac response evoked by blood pressure decreases caused by i.v. infusion of sodium nitroprusside. An increase in baroreflex gain was also observed. Baroreflex returned to control values 60 min after CoCl(2) microinjections, confirming its reversible effect. In conclusion, our data suggest that synapses within DBB have a tonic inhibitory influence on both the cardiac parasympathetic and sympathetic components of the baroreflex. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Bed nucleus of the stria terminalis alpha(1)-adrenoceptor modulates baroreflex cardiac component in unanesthetized rats

The bed nucleus of stria terminalis (BST) has a tonic modulating role on the baroreflex parasympathetic component. In the present study, we verified that local BST-adrenoceptors modulate baroreflex-evoked bradycardiac responses in unanesthetized rats. Bilateral microinjection of the selective alpha(1)-adrenoceptor antagonist WB4101 (15 nmol/100 nL) into the BST increased the gain of reflex bradycardia in response to mean arterial pressure increases caused by intravenous (i.v.) infusion of phenylephrine, suggesting that BST alpha(1)-adrenoceptors modulate baroreflex bradycardiac response. Bilateral microinjection of either the selective alpha(2)-adrenoceptor antagonist RX821002 (15 nmol/100 nL) or the non-selective beta-adrenoceptor antagonist propranolol (15 nmol/100 nL) into the BST had not affected baroreflex bradycardia. Animals were pretreated intravenously with the cholinergic muscarinic receptor antagonist homatropine methyl bromide (HMB, 1.5 mg/Kg) to test the hypothesis that activation of alpha(1)-adrenoceptors in the BST would modulate the baroreflex parasympathetic component. Baroreflex bradycardiac responses evoked before and after BST treatment with WB4101 were no longer different when rats were pretreated with HMB. These results suggest that parasympathetic activation accounts for the effects saw after BST pharmacological manipulation and ruling out the possibility of a sympathetic withdraw. In conclusion, our data point out that local alpha(1)-adrenoceptors mediate the BST tonic influence on the baroreflex bradycardiac response modulating parasympathetic cardiac activity. (C) 2008 Elsevier B.V. All rights reserved.

Increased activities of cardiac matrix metalloproteinases matrix metalloproteinase (MMP)-2 and MMP-9 are associated with mortality during the acute phase of experimental Trypanosoma cruzi infection

The strong inflammatory reaction that occurs in the heart during the acute phase of Trypanosoma cruzi infection is modulated by cytokines and chemokines produced by leukocytes and cardiomyocytes. Matrix metalloproteinases (MMPs) have recently emerged as modulators of cardiovascular inflammation. In the present study we investigated the role of MMP-2 and MMP-9 in T. cruzi-induced myocarditis, by use of immunohistochemical analysis, gelatin zymography, enzyme-linked immunosorbent assay, and real-time polymerase chain reaction to analyze the cardiac tissues of T. cruzi-infected C57BL/6 mice. Increased transcripts levels, immunoreactivity, and enzymatic activity for MMP-2 and MMP-9 were observed by day 14 after infection. Mice treated with an MMP inhibitor showed significantly decreased heart inflammation, delayed peak in parasitemia, and improved survival rates, compared with the control group. Reduced levels of cardiac tumor necrosis factor-alpha, interferon-gamma, serum nitrite, and serum nitrate were also observed in the treated group. These results suggest an important role for MMPs in the induction of T. cruzi-induced acute myocarditis.

Severity dependent increases in circulating cardiac troponin I and MMP-9 concentrations after experimental acute pulmonary thromboembolism

Background: Making the diagnosis of acute pulmonary thromboembolism (APT) and assessing its severity is very challenging, While cardiac troponin I (cTnI) concentrations are promising in risk stratification, no previous study has examined whether there is a linear relation between cTnI concentrations and the severity of APT. Moreover, matrix metalloprotemases (MMPs) are involved in the pathophysiology of APT. However, it is unknown whether the increases in MMP concentrations after APT reflect the severity of this condition. We examined whether the circulating concentrations of these biomarkers increase in proportion to the severity of experimental APT induced in anesthetized dogs. Methods: APT was induced with autologous blood clots (saline, 1, 3, or 5 ml/kg) injected into the right atrium. Hemodynamic evaluations were carried out for 120 min. Gelatin zymography of MMP-2 and MMP-9 from plasma samples were performed and serum cTnI concentrations were determined at baseline and 120 min after APT. Results: While no significant increases in pro-MMP-2 concentrations were found after APT, pro-MMP-9 concentrations increased by 80% only after 5 ml/kg of clot embolization. Serum cTnI and plasma pro-MMP-9 concentrations correlated positively with pulmonary vascular resistance (P=0.007 and rs=0.833 for troponin 1, and P=0.034 and rs=0.684 for pro-MMP-9) and with pulmonary artery pressure (P=0.005 and rs=0.610 for troponin 1, and P=0.022 and rs=0.720 for pro-MMP-9). Conclusions: Circulating cTnI and pro-MMP-9 increase in proportion to the severity of APT, although the increases in plasma pro-MMP-9 are less clear with less severe APT. These findings may be relevant for clinical APT. (C) 2007 Elsevier B.V. All rights reserved.

N-Methyl-D-aspartate glutamate receptors in the hypothalamic paraventricular nucleus modulate cardiac component of the baroreflex in unanesthetized rats

In the present study, we investigated the role played by the hypothalamic paraventricular nucleus (PVN) in the modulation of cardiac baroreflex activity in unanesthetized rats. Bilateral microinjections of the nonselective neurotransmission blocker CoCl(2) into the PVN decreased the reflex bradycardic response evoked by blood pressure increases, but had no effect on reflex tachycardia evoked by blood pressure decreases. Bilateral microinjections of the selective NMDA glutamate receptor antagonist LY235959 into the PVN caused effects that were similar to those observed after microinjections of CoCl(2), decreasing reflex bradycardia without affecting tachycardic response. The microinjection of the selective non-NMDA glutamate receptor antagonist NBQX into the PVN did not affect the baroreflex activity. Also, the microinjection of L-glutamate into the PVN increased the reflex bradycardia, an effect opposed to that observed after PVN treatment with CoCl(2) or LY235959, and this effect of L-glutamate was blocked by PVN pretreatment with LY235959. LY235959 injected into the PVN after iv. treatment with the selective beta(1)-adrenoceptor antagonist atenolol still decreased the reflex bradycardia. Taken together, our results suggest a facilitatory influence of the PVN on the bradycardic response of the baroreflex through activation of local NMDA glutamate receptors and a modulation of the cardiac parasympathetic activity. (C) 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Non-N-methyl-d-aspartate glutamate receptors in the lateral hypothalamus modulate cardiac baroreflex responses in conscious rats

P>In the present study, we investigated the effects of inhibition of the lateral hypothalamus (LH) neurotransmission with bilateral microinjection of CoCl(2), a non-selective blocker of neurotransmission, on modulation of cardiac baroreflex responses in conscious rats as well as the involvement of LH glutamatergic neurotransmission in this modulation. Reflex bradycardiac and tachycardiac responses to blood pressure increases (following i.v. infusion of phenylephrine) or decreases (following i.v. infusion of sodium nitroprusside) were investigated in conscious male Wistar rats. Responses were evaluated before and after microinjection of 1 nmol/100 nL CoCl(2), 2 nmol/100 nL 1,2,3,4-tetrahydro-6-nitro-2,3-dioxobenzoquinoxaline-7-sulphonamide (NBQX; a selective non-N-methyl-d-aspartate (NMDA) glutamate receptor antagonist) or different doses (2, 4 or 8 nmol/100 nL) of the selective NMDA glutamate receptor antagonist LY235959. Microinjection of CoCl(2) into the LH had no effect on the tachycardiac baroreflex response, but did evoke a decrease in the reflex bradycardia caused by increases in blood pressure. Microinjection of NBQX into the LH had a similar effect on reflex bradycardia as CoCl(2), but had no effect on the tachycardiac response. Microinjection of increasing doses of LY235959 into the LH had no effect on the cardiac baroreflex response. In conclusion, the data suggest that the LH has a tonic facilitatory influence on the parasympathetic component of the baroreflex. The results also indicate that this facilitatory influence is mediated by local LH glutamatergic neurotransmission through non-NMDA glutamatergic receptors.

Matrix Metalloproteinase Inhibition Improves Cardiac Dysfunction and Remodeling in 2-Kidney, 1-Clip Hypertension

Background: Enhanced cardiac matrix metalloproteinase activity (MMPs) has been associated with ventricular remodeling and cardiac dysfunction. It is unknown whether MMPs contribute to systolic/diastolic dysfunction and compensatory remodeling in 2-kidney, 1-clip (2K1C) hypertensive rats. To test this hypothesis, we used 2K1C rats after 2 weeks of surgery treated or not with a nonspecific inhibitor of MMPs (doxycycline). Methods and Results: We found that blood pressure and +/-dP/dt increased in 2K1C rats compared with sham groups, and these parameters were attenuated by doxycycline treatment (P < .05). Doxycycline also reversed cardiac hypertrophy observed in 2K1C rats (P < .05). Hypertensive rats showed increased MMP-2 levels in zymograms and in the tissue by immunofluorescence (P < .05) compared with sham groups. Increased total gelatinolytic activity was observed in untreated 2K1C rats when compared with sham groups (P < .05). Doxycycline decreased total gelatinolytic activity in 2K1C rats to control levels (P < .05). Conclusion: An imbalance in gelatinolytic activity, with increased MMP-2 levels and activity underlies the development of morphological and functional alterations found in the compensatory hypertrophy observed in 2K1C hearts. Because function and structure were restored by doxycycline, the inhibition of MMPs or their modulation may provide beneficial effects for therapeutic intervention in cardiac hypertrophy. (J Cardiac Fail 2010;16:599-608)

Changes in hemodynamic and neurohumoral control cause cardiac damage in one-kidney, one-clip hypertensive mice

Borges GR, Salgado HC, Silva CA, Rossi MA, Prado CM, Fazan R Jr. Changes in hemodynamic and neurohumoral control cause cardiac damage in one-kidney, one-clip hypertensive mice. Am J Physiol Regul Integr Comp Physiol 295: R1904-R1913, 2008. First published October 1, 2008; doi:10.1152/ajpregu.00107.2008.-Sympathovagal balance and baroreflex control of heart rate (HR) were evaluated during the development (1 and 4 wk) of one-kidney, one-clip (1K1C) hypertension in conscious mice. The development of cardiac hypertrophy and fibrosis was also examined. Overall variability of systolic arterial pressure (AP) and HR in the time domain and baroreflex sensitivity were calculated from basal recordings. Methyl atropine and propranolol allowed the evaluation of the sympathovagal balance to the heart and the intrinsic HR. Staining of renal ANG II in the kidney and plasma renin activity (PRA) were also evaluated. One and four weeks after clipping, the mice were hypertensive and tachycardic, and they exhibited elevated sympathetic and reduced vagal tone. The intrinsic HR was elevated only 1 wk after clipping. Systolic AP variability was elevated, while HR variability and baroreflex sensitivity were reduced 1 and 4 wk after clipping. Renal ANG II staining and PRA were elevated only 1 wk after clipping. Concentric cardiac hypertrophy was observed at 1 and 4 wk, while cardiac fibrosis was observed only at 4 wk after clipping. In conclusion, these data further support previous findings in the literature and provide new features of neurohumoral changes during the development of 1K1C hypertension in mice. In addition, the 1K1C hypertensive model in mice can be an important tool for studies evaluating the role of specific genes relating to dependent and nondependent ANG II hypertension in transgenic mice.

Increased cardiac sympathetic drive and reduced vagal modulation following endothelin receptor antagonism in healthy conscious rats

1. The present study evaluated changes in autonomic control of the cardiovascular system in conscious rats following blockade of endothelin (ET) receptors with bosentan. 2. Rats were treated with bosentan or vehicle (5% gum arabic) for 7 days by gavage. 3. Baseline heart rate (HR) was higher in the bosentan-treated group compared with the control group (418 +/- 5 vs 357 +/- 4 b.p.m., respectively; P < 0.001). This baseline tachycardia was associated with a lower baroreflex sensitivity of the bradycardiac and tachycardiac responses in the bosentan-treated group compared with the control group. Sequential blockade of the parasympathetic and sympathetic autonomic nervous system with methylatropine and propranolol showed a higher intrinsic HR in the bosentan-treated group compared with the control group (411 +/- 5 vs 381 +/- 4 b.p.m., respectively; P < 0.05). This was accompanied by a higher cardiac sympathetic tone (31 +/- 1 vs 13 +/- 1%, respectively; P < 0.01) and a lower vagal parasympathetic tone (69 +/- 2 vs 87 +/- 2%, respectively; P < 0.01) in the bosentan-treated group compared with the control group. Variance and high-frequency oscillations of pulse interval (PI) variability in absolute and normalized units were lower in the bosentan-treated group than in the control group. Conversely, low-frequency (LF) oscillations of PI variability in absolute and normalized units, as well as variance and LF oscillations of systolic arterial pressure variability, were greater in the bosentan-treated group than the control group. 4. Overall, the data indicate an increased cardiac sympathetic drive, as well as lower vagal parasympathetic activity and baroreflex sensitivity, in conscious rats after chronic blockade of ET receptors with bosentan.

Covariance functions for body weight from birth to maturity in Nellore cows

The objective of this study was to estimate (co)variance functions using random regression models on Legendre polynomials for the analysis of repeated measures of BW from birth to adult age. A total of 82,064 records from 8,145 females were analyzed. Different models were compared. The models included additive direct and maternal effects, and animal and maternal permanent environmental effects as random terms. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of animal age (cubic regression) were considered as random co-variables. Eight models with polynomials of third to sixth order were used to describe additive direct and maternal effects, and animal and maternal permanent environmental effects. Residual effects were modeled using 1 (i.e., assuming homogeneity of variances across all ages) or 5 age classes. The model with 5 classes was the best to describe the trajectory of residuals along the growth curve. The model including fourth- and sixth-order polynomials for additive direct and animal permanent environmental effects, respectively, and third-order polynomials for maternal genetic and maternal permanent environmental effects were the best. Estimates of (co) variance obtained with the multi-trait and random regression models were similar. Direct heritability estimates obtained with the random regression models followed a trend similar to that obtained with the multi-trait model. The largest estimates of maternal heritability were those of BW taken close to 240 d of age. In general, estimates of correlation between BW from birth to 8 yr of age decreased with increasing distance between ages.