Interleukin-6 and insulin incrase and nitric oxide and adiponectin decrease in blind dogs with pituitary-dependent hyperadrenocorticism

Inverse relationship between eosinophil profiles and serum glucose concentration in dogs with naturally occurring hypercortisolism

Hyperglycemia and eosinopenia are well-known characteristics of hypercortisolism (HC) in humans, however, their association in dogs with HC has rarely been reported. This study aimed to evaluate the association between eosinophils and serum fasting glucose concentration in dogs with HC. Forty-seven dogs with HC and 43 dogs with non-adrenal illness were included. In this retrospective cohort study, the complete blood count, blood chemistry profile, and pre- and post-adrenocorticotropic hormone (ACTH) cortisol concentrations were analyzed. Significant differences were found in neutrophil, monocyte, eosinophil, and platelet counts; eosinophil percentage; neutrophil-to-lymphocyte ratio; aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase activities (P < 0.05) between the groups. In dogs with HC, the eosinophil percentage was inversely correlated with fasting blood glucose (r = -0.3515, P = 0.0154) and post-ACTH cortisol concentrations (r = -0.6509, P < 0.0001). The neutrophil-to-lymphocyte ratio was inversely correlated with the eosinophil percentage (r = -0.4573, P = 0.0012) and count (r = -0.3688, P = 0.0108), but positively correlated with the fasting blood glucose level (r = 0.3888, P = 0.0069). Such correlations were not identified in dogs with non-adrenal illness. A multivariate analysis showed that only eosinophil percentage was associated with the presence of hyperglycemia in dogs with HC (odds ratio = 2.100, 95% confidence interval = 1.051-4.199, P = 0.0360). Therefore, eosinopenia induced by excess cortisol might be associated with altered glucose metabolism in dogs with HC. A better understanding of this correlation could be valuable to predict and prevent the complications of HC.

Fenofibrate treatment for severe hypertriglyceridemia in dogs

Lipid disorders are relatively common in dogs. Hyperlipidemia can be primary or secondary to other diseases. In humans, fenofibrate is used to control hypertriglyceridemia. In dogs, there are no studies evaluating fenofibrate in hypertriglyceridemia. The aim of the study was to evaluate the safety and efficacy of fenofibrate to control severe hypertriglyceridemia in dogs. A total of 124 dogs (n = 124) with severe hypertriglyceridemia (>300 mg/dL, 3.39 mmol/L) were randomly distributed in the fenofibrate group (n = 64) and the diet group (n = 60). Dogs of the fenofibrate group were treated with fenofibrate (10 mg/Kg) once daily. Dogs of the diet group were treated with low-fat diet (10%). Serum triglycerides (TGs), total cholesterol (TC), liver enzymes, and creatine kinase concentrations were evaluated, before and after 1 mo of medical or dietary treatment. Triglyceride concentrations were reduced with fenofibrate (P < 0.001), and 85.93% of the dogs normalized their levels. Triglyceride concentrations also decreased with low-fat diet (P < 0.001), but only 26.6% of the dogs normalized their levels. Triglyceride concentrations were reduced with fenofibrate (P < 0.01) and with low-fat diet (P < 0.01). Of the cases with hypercholesterolemia, 53.7% and 50% of the dogs normalized their TC concentrations, with fenofibrate and diet, respectively. No significant adverse effects were observed (3% showed diarrhea). Fenofibrate was safe and effective in reducing and normalizing TG concentrations in dogs with severe hypertriglyceridemia, regardless of the cause of hyperlipidemia. The low-fat diet was effective in reducing, but not normalizing, TG concentrations. Fenofibrate and low-fat diet were effective in reducing TC concentrations. This is the first study evaluating fibrates in dogs with severe hypertriglyceridemia and comparing results with a low-fat diet.

A preliminary evaluation of the circulating leptin/adiponectin ratio in dogs with pituitary-dependent hyperadrenocorticism and concurrent diabetes mellitus

Leptin and adiponectin are thought to modulate insulin sensitivity and pancreatic β-cell function, but there is limited information regarding the adipokine status of hyperglycemic dogs with hyperadrenocorticism. This study aimed to determine whether alterations in the leptin/adiponectin ratio, insulin sensitivity, and/or pancreatic β-cell function are associated with diabetes mellitus (DM) in dogs with pituitary-dependent hyperadrenocorticism (PDH). A total of 48 client-owned dogs were included in this prospective observational study: 20 dogs with PDH (10 normoglycemic and 10 with DM), 15 dogs with DM, and 13 healthy dogs. The serum concentrations of leptin, adiponectin, resistin, interleukin (IL)-1β, IL-6, IL-10, IL-18, and tumor necrosis factor (TNF)-α were measured, and homeostatic model assessment indices (HOMAs) were calculated and compared among the groups. Serum leptin was significantly higher in PDH dogs with and without DM than in healthy and DM dogs, and it was lower in DM dogs than in PDH dogs without DM. Serum adiponectin was significantly lower in PDH dogs with DM than in healthy and PDH dogs, and it was significantly lower in DM dogs than in healthy dogs. Serum IL-10 was significantly higher in PDH dogs with DM than in healthy and PDH dogs without DM. The leptin/adiponectin ratio was significantly higher in PDH dogs with DM than in normoglycemic PDH dogs. Serum IL-6 concentrations were significantly higher in DM dogs than in healthy dogs. Serum IL-1β concentration was significantly higher in DM dogs than in healthy dogs and PDH dogs with DM and without DM. Serum TNF-α and IL-18 concentrations were not different among groups. The HOMA_{β-cell function} was significantly lower in PDH dogs with DM than in normoglycemic PDH dogs, while HOMA_{insulin sensitivity} was significantly lower in PDH dogs with DM than in healthy dogs. These results suggest that adipokine dysregulation, a reduction in insulin sensitivity, and a further impairment in pancreatic β-cell function might predispose PDH dogs to DM. Further longitudinal study will be necessary to confirm this result.

Diagnosis of spontaneous hyperadrenocorticism in dogs. Part 1: Pathophysiology, aetiology, clinical and clinicopathological features

Hyperadrenocorticism is a relatively common endocrine disorder in dogs. It occurs as a result of a functional pituitary or adrenal tumour, although other causes have been rarely reported. Canine hyperadrenocorticism has been extensively described but diagnosing this disease remains challenging. Few studies have investigated the clinical and clinicopathological features helpful in differentiating dogs with hyperadrenocorticism from dogs in which the disease is suspected but eventually excluded. Ultimately the diagnosis is based on a combination of multiple pieces of information emanating from the signalment, history, clinical findings, and a variety of diagnostic tests. The first part of this review aims to critically appraise the available data on epidemiology, clinical and laboratory features of naturally occurring canine hyperadrenocorticism.

Decrease of nitric oxide and increase in diastolic blood pressure are two events that affect renal function in dogs with pituitary dependent hyperadrenocorticism

Hyperadrenocorticism is a frequent disease in dogs. The excess of circulating cortisol affects different organs and metabolic pathways, producing severe adverse effects that endanger the animal’s life. Among these effects, hypertension and renal damage can be mentioned. A group of 20 dogs with pituitary dependent hyperadrenocorticism (PDH) and 12 control dogs were used to study the following parameters: cortisol and nitric oxide (NO nit/nit) concentrations, diastolic and systolic blood pressure, renal artery resistance index by Doppler ultrasound, the rate of glomerular filtration by radio-renogram excretion and the presence of proteins in urine. Dogs with PDH showed a significantly lower NO nit/nit (P<0.0001) than the controls and this correlated with high values of diastolic and systolic pressure (r = -0.87; P<0.0001 and r = -0.81; P<0.0001 respectively). Most dogs (80%) are hypertensive mainly due to an increase in diastolic pressure, which correlated positively with the UPC (r = 0.8; P<0.001) and negatively with the glomerular rate of filtration (r = -0.58; P=0.007). Systolic pressure only increased in 60% of the cases and did not correlate with the mentioned variables. In PDH the decrease of NO affects blood pressure. The diastolic pressure would seem to have the greatest impact on the kidneys, therefore its evaluation and control are important to avoid and/or control renal damage.

Heat Shock Proteins 70kDa, Eosinophil Cationic Protein, and Nitric Oxide During Chronic Superficial Keratitis in Dogs

The objective of the study is to determine the levels of eosinophil cationic protein (ECP), heat shock proteins 70, and nitric oxide ions measured as nitrite ions (Griess reaction) in dogs with chronic superficial keratitis (CSK). The study was conducted on 24 dogs with CSK. Blood sera from the animals were tested for concentrations of heat shock proteins 70, ECP, and nitrite ions before treatment and again 5 weeks and 6 months after treatment. Dogs with CSK were treated for 6 months with various regimes involving the use of ophthalmic drops containing dexamethasone, dimethyl sulfoxide, and cyclosporine. The control group consisted of 16 clinically healthy German Shepherds. The results obtained indicated a significant (P ≤ 0.05) elevation in the concentrations of heat shock proteins 70 and nitrite ions in dogs with CSK in comparison to healthy dogs and dogs after 5 weeks of therapy. After 6 months of treatment, concentrations of heat shock proteins 70, ECP, and nitrite ions had fallen below pretreatment values. Significant correlations were found between concentrations of heat shock proteins 70, ECP, and nitrite ions in healthy animals and animals with CSK. The elevated concentrations of heat shock proteins 70, ECP, and nitrite ions in dogs with CSK may indicate that the disease was both localized and systemic. The significant correlation between levels of heat shock proteins 70 and nitrite ions suggests that these parameters may be used as indirect indicators of CSK.

Concurrent hyperadrenocorticism and diabetes mellitus in dogs

Hyperadrenocorticism (HAC) and diabetes mellitus (DM) are two diseases that can occur concurrently in dogs. The objective of this study was to evaluate the coexistence of HAC and DM, and the risk factors involved that could contribute to the development of DM in dogs with HAC. A total of 235 dogs with HAC were studied and, according to their fasting glycemia, they were divided into three groups: <5.6mmol/L, between 5.6 and 10.08mmol/L and >10.08mmol/L. The following parameters were evaluated: age, gender, cause of HAC, body condition, glycemia, total cholesterol, triglycerides, urinary cortisol:creatinin ratio (UCCR) and survival time. A 13.61% concurrence of HAC and DM was observed. Dogs with a fasting glycemia >5.6mmol/L, with dislipemia, with Pituitary-Dependent Hyperadrenocorticism, UCCR >100×10^-6 and non-castrated females showed a higher risk of developing DM. The development of DM in dogs with HAC reduces the survival time.

Biomarkers for differentiation of causes of respiratory distress in dogs and cats: Part 2--Lower airway, thromboembolic, and inflammatory diseases

OBJECTIVES

To review the current veterinary and relevant human literature regarding biomarkers of respiratory diseases leading to dyspnea and to summarize the availability, feasibility, and practicality of using respiratory biomarkers in the veterinary setting.

DATA SOURCES

Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent textbooks.

HUMAN DATA SYNTHESIS

Numerous biomarkers have been evaluated in people for discriminating respiratory disease processes with varying degrees of success.

VETERINARY DATA SYNTHESIS

Although biomarkers should not dictate clinical decisions in lieu of gold standard diagnostics, their use may be useful in directing care in the stabilization process. Serum immunoglobulins have shown promise as an indicator of asthma in cats. A group of biomarkers has also been evaluated in exhaled breath. Of these, hydrogen peroxide has shown the most potential as a marker of inflammation in asthma and potentially aspiration pneumonia, but methods for measurement are not standardized. D-dimers may be useful in screening for thromboembolic disease in dogs. There are a variety of markers of inflammation and oxidative stress, which are being evaluated for their ability to assess the severity and type of underlying disease process. Of these, amino terminal pro-C-type natriuretic peptide may be the most useful in determining if antibiotic therapy is warranted. Although critically evaluated for their use in respiratory disorders, many of the biomarkers which have been evaluated have been found to be affected by more than one type of respiratory or systemic disease.

CONCLUSION

At this time, there are point-of-care biomarkers that have been shown to reliably differentiate between causes of dyspnea in dogs and cats. Future clinical research is warranted to understand of how various diseases affect the biomarkers and more bedside tests for their utilization.

Interleukin 6 increases the in vitro expression of key proteins associated with steroidogenesis in the bovine adrenal zona fasciculata

In this study, the in vitro effects of interleukin 6 (IL-6) on the messenger RNAs (mRNAs) and proteins for key steroidogenic factors in the bovine adrenal zona fasciculata (ZF) were determined. Bovine adrenal glands were obtained from an abattoir, and the ZF was isolated. Strips of ZF were then exposed to different concentration of murine IL-6 and/or adrenocorticotropic hormone (ACTH) for various intervals, the protein and mRNA extracted, and the mRNA and protein expression determined by real-time polymerase chain reaction and Western blots. Exposure (1 h) to IL-6 increased in a concentration-dependent manner (10-pg IL-6/mL, P < 0.05 vs control; 100-pg IL-6/mL, P < 0.01 vs control) the relative expression of the mRNAs and proteins for steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), 3β hydroxysteroid dehydrogenase type 2 (3β HSD), 17α-hydroxylase/17,20-lyase/17,20-desmolase (P450 17OH), steroid 21-hydroxylase (P450 21OH), steroid 11-β-hydroxylase type 1 (P450 11βOH), and steroidogenic factor 1 (SF-1), a nuclear factor that increases StAR and steroidogenic enzymes (SEs) expression. Similarly, IL-6 (10 pg/mL) increased the relative expression of proteins and mRNAs for StAR, P450scc, 3β HSD, P450 17OH, P450 21 OH, P450 11βOH, and SF-1 in a time-dependent manner (30 min, P < 0.05 vs control; 60, 120, and 240 min, P < 0.01 vs control). In contrast, IL-6 decreased in a concentration-dependent (P < 0.01 vs control for 1, 10, and 100 pg IL-6/mL) and time-dependent (P < 0.05 vs control for 30, 60,120, and 240 min of 10 pg IL-6/mL) manner the relative expression of the mRNA and protein for adrenal hypoplasia congenita-like protein (DAX-1), a nuclear factor that decreases expression of StAR and SEs. Incubation (1 h) of ZF with 100-nM ACTH increased (P < 0.05 vs control) the relative expression of StAR, P450scc, 3β HSD, P450 17OH, P450 21OH, P450 11βOH, and SF-1 and decreased (P < 0.01 vs control) the relative expression of DAX-1. Murine IL-6 (10 pg/mL) augmented (P < 0.05 vs ACTH) both the stimulatory and inhibitory effects of ACTH. Bovine IL-6 (100 pg/mL, 1-h incubation) also increased (P < 0.01 vs control) the relative expression of the proteins for StAR, P450scc, and SF-1 and decreased (P < 0.01 vs control) the relative expression of DAX-1. In summary, IL-6 increased ZF expression of StAR and 5 SEs, which may be mediated in part by decreasing DAX-1 expression and increasing SF-1 expression.

Serum adipokine concentrations in dogs with naturally occurring pituitary-dependent hyperadrenocorticism

BACKGROUND

An excess of intra-abdominal fat is observed frequently in dogs with hyperadrenocorticism (HAC). Adipokine dysregulation is a possible cause of complications related to visceral obesity, but little information is available on adipokine in dogs with naturally occurring HAC.

OBJECTIVES

To examine the differences in the circulating adipokines concentrations in overweight dogs with and without pituitary-dependent HAC (PDH).

ANIMALS

Thirty healthy dogs and 15 client-owned dogs with PDH.

METHODS

Case-controlled observational study, which enrolled 15 overweight dogs diagnosed with PDH and 30 otherwise healthy dogs of similar body condition score. Nine of 15 dogs with PDH were treated with low-dose trilostane twice daily and reassessed after treatment.

RESULTS

The serum leptin (P < .0001) and insulin (P < .0001) concentrations were significantly higher in the PDH group (leptin, 22.8 ± 8.8 [mean ± SD]; insulin, 9.1 ± 6.1) than the healthy group (leptin, 4.9 ± 3.7; insulin, 1.9 ± 0.9). However, there were no significant differences in the adiponectin, resistin, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10, and IL-18 levels between the 2 groups. In the PDH group, the serum cortisol concentrations had a linear association with the leptin concentrations, and there were significant decreases in the leptin (P = .0039) and insulin (P = .0039) levels after trilostane treatment. However, the leptin and insulin levels remained higher after trilostane treatment than in healthy control dogs with similar body condition score.

CONCLUSIONS AND CLINICAL IMPORTANCE

Hypercortisolemia in dogs with PDH might upregulate the circulating leptin levels. However, a large population-based study will be necessary to determine whether the upregulation of leptin is involved directly with the complications caused by HAC.