Palatability, glycemic, and insulinemic responses to various carbohydrate formulations: Alternatives for the diagnosis of insulin dysregulation in horses?

Background: Oral glycemic challenge (GC) tests are recommended for diagnosis of insulin dysregulation (ID). Various protocols are used, but all have limitations in terms of palatability, ease of use, variable composition, geographic availability, or some combination of these.

Hypothesis/objective: To evaluate newly developed formulations with defined carbohydrate composition for use as oral GCs.

Carbohydrate pellets to assess insulin dysregulation in horses.

Background: A glycemic challenge test is used for the diagnosis of insulin dysregulation (ID) in horses and ponies. Different forms of the test exist where the administrative route and dose of glucose vary, which makes interpretation of results challenging.

Hypothesis/objectives: To evaluate the palatability of, and blood glucose and insulin responses to, carbohydrate pellets fed as an oral glucose test (OGT), and to establish the diagnostic threshold for ID when using the pellets.

Demographic, morphologic, hormonal and metabolic factors associated with the rate of improvement from equine hyperinsulinaemia-associated laminitis.

Background: Although several studies have investigated factors associated with the onset and occurrence of hyperinsulinaemia-associated laminitis (HAL), few have examined the factors associated with the rate of improvement during recovery from an acute bout of the disease. This observational study sought to discover if a range of demographic, morphologic, hormonal and metabolic variables are associated with the improvement rate from HAL in 37 naturally-occurring cases identified by 16 clinics across Germany. Each case was evaluated for laminitis severity on the day of inclusion in the trial (d 0), then after 4, 9, 14, 25 and 42 d.

Metabolic profile distinguishes laminitis-susceptible and -resistant ponies before and after feeding a high sugar diet.

Background: Insulin dysregulation (ID) is a key risk factor for equine endocrinopathic laminitis, but in many cases ID can only be assessed accurately using dynamic tests. The identification of other biomarkers could provide an alternative or adjunct diagnostic method, to allow early intervention before laminitis develops. The present study characterised the metabolome of ponies with varying degrees of ID using basal and postprandial plasma samples obtained during a previous study, which examined the predictive power of blood insulin levels for the development of laminitis, in ponies fed a high-sugar diet.

Component-resolved microarray analysis of IgE sensitization profiles to Culicoides recombinant allergens in horses with insect bite hypersensitivity.

Background: Allergy to bites of blood-sucking insects, including biting midges, can affect both human and veterinary patients. Horses are often suffering from an IgE-mediated allergic dermatitis caused by bites of midges (Culicoides spp). With the aim to improve allergen immunotherapy (AIT), numerous Culicoides allergens have been produced as recombinant (r-) proteins.

Cul o 2 specific IgG3/5 antibodies predicted Culicoides hypersensitivity in a group imported Icelandic horses.

Background: Culicoides hypersensitivity (CH) is induced in horses by salivary allergens of Culicoides midges. In Iceland, the causal Culicoides species for CH are not present. Previous epidemiological data indicated that Icelandic horses are more susceptible to CH when they are exported from Iceland and first exposed to Culicoides at adult age.

A "modified Obel" method for the severity scoring of (endocrinopathic) equine laminitis.

Background: Laminitis is a common equine disease characterized by foot pain, and is commonly diagnosed using a five-grade Obel system developed in 1948 using sepsis-related cases. However, endocrinopathic laminitis is now the most common form of the disease and clinical signs may be mild, or spread across two Obel grades. This paper describes a modified method which assigns scores to discreet clinical signs, providing a wider scale suitable for use in a research setting.

Incidence and risk factors for recurrence of endocrinopathic laminitis in horses.

Background: Endocrinopathic laminitis is common in horses and ponies, but the recurrence rate of the disease is poorly defined.

Objectives: To determine the incidence of, and risk factors for, the recurrence of endocrinopathic laminitis.

Animals: Privately owned horses and ponies with acute laminitis (n = 317, of which 276 cases with endocrinopathic laminitis were followed up to study completion).

Phenotypic, hormonal, and clinical characteristics of equine endocrinopathic laminitis.

Background: Equine endocrinopathic laminitis is common and can be associated with an underlying endocrinopathy, such as equine metabolic syndrome (EMS), pituitary pars intermedia dysfunction (PPID), pasture consumption, or any combination of these factors.

Objectives: The aim of the study was to improve the risk assessment capabilities of clinicians, and to inform management strategies, for acute endocrinopathic laminitis by prospectively examining the phenotypic, hormonal, and clinical characteristics of the disease in a large cohort.

Animals: Privately owned horses and ponies (n = 301) of any age, sex, or breed diagnosed with laminitis by a veterinarian.

Neutral endopeptidase inhibitors blunt kidney fibrosis by reducing myofibroblast formation.

Kidney fibrosis is the common pathophysiological mechanism in end-stage renal disease characterized by excessive accumulation of myofibroblast-derived extracellular matrix. Natriuretic peptides have been demonstrated to have cyclic guanosine monophosphate (cGMP)-dependent anti-fibrotic properties likely due to interference with pro-fibrotic tissue growth factor β (TGF-β) signaling. However, , natriuretic peptides are rapidly degraded by neutral endopeptidases (NEP).

The sodium-glucose co-transporter 2 inhibitor velagliflozin reduces hyperinsulinemia and prevents laminitis in insulin-dysregulated ponies.

There are no registered veterinary drugs for treating insulin dysregulation and preventing insulin-associated laminitis in horses. Velagliflozin is a sodium-glucose co-transport 2 inhibitor that reduces renal glucose reabsorption, promotes glucosuria, and consequently, decreases blood glucose and insulin concentrations. This study aimed to determine if velagliflozin reduced hyperinsulinemia and prevented laminitis in insulin-dysregulated ponies fed a challenge diet high in non-structural carbohydrates (NSC).

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4) in Cows with Subclinical Ketosis.

The inhibition of dipeptidyl peptidase-4 (DPP4) via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA) and ketone bodies.

Effects of elevated parameters of subclinical ketosis on the immune system of dairy cows: in vivo and in vitro results.

Using an established model in which subclinical ketosis is induced, the response of differential blood counts and levels of various haematological variables, including the inflammatory marker haptoglobin (Hp), were tested over the last six weeks of parturition until the 56th day post-partum in cows with lower or higher body condition scores (LBC and HBC, respectively; n = 9/group). Animals in the HBC group evidenced subclinical ketosis whereas LBC animals were metabolically healthy. For in vitro examination with ß-hydroxybutyrate (BHB) as a further stimulus, peripheral blood mononuclear cell (PBMC) counts of cows with and without subclinical ketosis (n = 5/group) were observed.

Effects of prepartal body condition score and peripartal energy supply of dairy cows on postpartal lipolysis, energy balance and ketogenesis: an animal model to investigate subclinical ketosis.

Subclinical ketosis is a metabolic disorder which often goes undiagnosed and leads to constricted performance and an impairment of general condition. In the current study subclinical ketosis was characterised by a β-hydroxybutyrate (BHB) concentration of >1·2 mmol/l in blood serum. To generate this metabolic situation, an animal model was created.

Assessment of impaired vascular reactivity in a rat model of diabetic nephropathy: effect of nitric oxide synthesis inhibition on intrarenal diffusion and oxygenation measured by magnetic resonance imaging.

Diabetes is associated with impaired vascular reactivity and the development of diabetic nephropathy. In a rat model of streptozotocin-induced diabetic nephropathy, the effects of systemic nitric oxide (NO) synthesis inhibition on intrarenal diffusion and oxygenation were determined by noninvasive magnetic resonance diffusion tensor imaging and blood O2 level-dependent (BOLD) imaging, respectively. Eight weeks after the induction of diabetes, 21 rats [n = 7 rats each in the untreated control group, diabetes mellitus (DM) group, and DM with uninephrectomy (DM UNX) group] were examined by MRI.

Magnetic resonance diffusion tensor imaging for evaluation of histopathological changes in a rat model of diabetic nephropathy.

Objectives: The aim of this study was to investigate whether magnetic resonance (MR) diffusion tensor imaging (DTI) allows assessment of renal pathologies in a rat model of diabetic nephropathy.

Materials And Methods: Twenty-one male Sprague-Dawley rats were divided into 3 groups: (1) untreated controls, (2) diabetes (DM), (3) diabetes with uninephrectomy (DM UNX) to accelerate renal impairment. Eight weeks after diabetes induction with streptozotocin, MR imaging was performed in a 1.

Some cannabinoid receptor ligands and their distomers are direct-acting openers of SUR1 K(ATP) channels.

Here, we examined the chronic effects of two cannabinoid receptor-1 (CB1) inverse agonists, rimonabant and ibipinabant, in hyperinsulinemic Zucker rats to determine their chronic effects on insulinemia. Rimonabant and ibipinabant (10 mg·kg⁻¹·day⁻¹) elicited body weight-independent improvements in insulinemia and glycemia during 10 wk of chronic treatment. To elucidate the mechanism of insulin lowering, acute in vivo and in vitro studies were then performed.

Cholinergic and noncholinergic innervation of the smooth muscle layers in the bovine abomasum.

The intrinsic innervation of muscle layers in the mammalian gastrointestinal tract has been mainly studied in nonruminants. The aim of this study was to identify intrinsic motor neurones in the bovine abomasum that innervate the circular and longitudinal muscles. Circular (CMN) and longitudinal muscle motor neurones (LMN) were selectively labeled by application of the retrograde tracer 1,1'-didodecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate (DiI) onto the muscle layers.