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.     

The effect of mid-pregnancy stressors on twin-lamb live weight and body dimensions at birth

This study was conducted to determine the effect of crutching, simulated shearing and conventional shearing in mid-pregnancy on maternal plasma cortisol levels and lamb live weight and body dimensions at birth. Twin-bearing Romney ewes (n = 96) were subjected to one of four treatments (control, crutched, sham shorn and shorn) on day 80 of pregnancy. Ewes were maintained as a single flock throughout pregnancy under commercial farming conditions. Within 12 h of birth the lambs were weighed and their body dimensions recorded. Lambs born to ewes shorn in mid-pregnancy were heavier (P < 0.05) at birth than lambs born to control or sham-shorn ewes by 300 and 400 g (7 and 10%) respectively. The birth weight of lambs born to crutched and control ewes did not differ. Shearing and crutching produced a greater integrated cortisol response than sham-shearing (P < 0.05). The failure of crutching to increase lamb birth weight suggests that the acute stress caused by shearing does not result in increased lamb birth weights.     

Serum cortisol and progestin concentrations in pregnant and non-pregnant Asian elephants (Elephas maximus)

Blood samples were collected during the estrous cycle (n=3), throughout gestation (n=3), and during the periparturient period (n=11) to assess serum concentrations of cortisol in pregnant and non-pregnant Asian elephants whose reproductive status was being monitored by serum progestin determination. While serum cortisol concentrations remained constant throughout gestation, progestin concentrations decreased significantly (p<0.05) in the second half of pregnancy, declining to undetectable levels by 3 days before calving. During the non-luteal phase of the estrous cycle serum progestins varied from undetectable levels to 100pg/ml (53+/-10.7pg/ml) then increased steadily during the luteal phase (322+/-207.5pg/ml). There were no significant differences between serum cortisol concentrations during the luteal and those of the non-luteal phase (p>0.05). The mean cortisol concentration during the estrous cycle was about twice that during pregnancy (p>0.05). No substantial changes in maternal cortisol were found during the course of pregnancy or the periparturient period.     

运输密度和盐度对大黄鱼幼鱼皮质醇、糖元及乳酸含量的影响

为了确定大黄鱼运输的适宜条件,实验选取平均体质量为(0.12±0.03)g的大黄鱼幼鱼为实验对象,采取析因设计,设3个运输密度(2、4和8 g/L)和5个运输盐度(5、10、15、20和25),共计15个处理组研究了不同密度和盐度运输条件下,大黄鱼幼鱼皮质醇、糖元及乳酸含量的变化。经过水温16.5℃、10 h的运输,统计各组的死亡率,测定各组水中总氨氮含量。结果显示,在运输结束后,4和8 g/L密度组死亡率(1.33%、2.63%)显著高于2 g/L密度组(0.77%),盐度25组死亡率(0.44%)显著低于盐度10、15组(1.94%、1.67%),盐度10、15组死亡率显著低于盐度5组(2.72%),各组水中总氨氮含量较运输前(0.15 mg/L)均显著升高,各密度组水中总氨氮含量均有显著性差异,高密度组总氨氮含量高于低密度组,8 g/L密度条件下盐度5组水中总氨氮含量(1.63 mg/L)显著高于盐度15(1.38 mg/L)、盐度20(1.34 mg/L)和盐度25(1.31 mg/L)组,4 g/L密度条件下盐度5组水中总氨氮含量(1.31mg/L)显著高于其他各盐度组,2 g/L密度条件下盐度5组水中总氨氮含量(0.83 mg/L)显著高于盐度25组(0.49 mg/L);运输胁迫导致各组皮质醇含量均较运输前(6 476.35 ng/L)显著升高,各组间皮质醇含量无显著性差异;各组糖元含量均较运输前(4.37 mg/g prot)显著降低,运输后各组间糖元含量无显著性差异;各组乳酸含量均较运输前(0.57 mmol/g prot)显著升高,运输后各密度组间乳酸含量无显著性差异,3个密度下盐度5组乳酸含量(1.91、2.02、1.76 mmol/g prot)均显著高于盐度20(1.55、1.21、1.69 mmol/g prot)和盐度25组(1.36、1.44、1.26 mmol/g prot),盐度10组乳酸含量(1.77、1.83、1.60 mmol/g prot)显著高于盐度25组(1.36、1.44、1.26 mmol/g prot)。研究表明,较高的运输密度和较低的盐度会加重大黄鱼的应激性反应,在本实验条件下,规格为0.1 g左右的大黄鱼幼鱼,其运输密度不宜超过8g/L,盐度不宜低于5。     

Cortisol Circadian Rhythm Ratio: A Simple Method to Detect Stressed Horses at Higher Risk of Colic?

With the hypothesis that police horses with abnormal cortisol circadian rhythm (CCR) had more chance to develop colic, the aim of this study was to determine the CCR ratio in horses subjected to different housing and work conditions and to associate abnormal CCR ratio with incidence of colic. A total of 116 police horses belonging to four different groups were studied. In all, 31 were full-time stabled and performed urban patrolling activity, 27 were full-time stabled and performed equine therapy and sports activities, 25 were part-time stabled and performed urban patrolling, and 33 animals were kept full-time on pasture and did not perform any kind of work activity. Venous blood samples were collected between 6 and 7 am and also 8 hours later, and cortisol concentrations were determined by radioimmunoassay to calculate the CCR ratio. Annual colic incidences (6 months before and after the day on which CCR ratio was determined) were assessed by examining individual medical files. The overall incidence of abnormal CCR ratio (<0.30) was 63.3%, and 107 cases of colic were reported for this population with a mean incidence of 0.92 colic/horse/yr. Horses with abnormal CCR had 2.3 times more chance to have colic (95% CI: 1.07 to 5.28, P = .03) when compared with those with normal CCR. In conclusion, high incidence of abnormal CCR ratio indicates that police horses were under stressful conditions. Horses with abnormal CCR ratios were more prone to suffer colic episodes, indicating that CCR ratio determination could perhaps be useful in detecting horses at risk of colic.     

追逐驱赶所引起的胁迫对鱼类先天性防御能力的影响

研究了由追著驱赶引起的胁迫对斑尾鲈先天性防御能力的影响。斑尾鲈具有好斗相残性，实验中观察到，将不同个体大小的斑尾鲈放入同一水体中几小时后，个体稍大的追逐驱赶个体稍小的，处于生态主导地位，而小鱼则处于从属地位。对小鱼血浆内的皮质醇含量进行测定，其值显著高于大鱼血浆内皮质醇的含量。处于胁迫当中。注射灭活细菌到鱼鳔内，游向鱼鳔的嗜中性粒细胞，受胁迫鱼明显少于非受胁迫鱼。且其吞噬活力和呼吸爆发活力也相应下降。同时，体外研究也表明，胁迫抑制了斑尾鲈嗜酸性粒细胞的脱粒。另外，用爱德华氏茵进行感染，注射皮质醇的鱼表现出明显的易感性。从以上的研究我们可以看出，胁迫环境下，皮质醇含量分泌的增加，损害了斑尾鲈的先天性防御能力，对外来病原微生物的入侵也缺乏相应的抵抗力。     

Cortisol and hematological response in Brazilian codling, Urophycis brasiliensis (Pisces, Phycidae) subjected to anesthetic treatment

The effects of benzocaine anesthesia on hematological parameters (erythrocyte and platelet number, hemoglobin concentration and hematocrit), plasma electrolytes (Na⁺, K⁺ and Cl⁻), cortisol, glucose and cholesterol levels in Brazilian codling (Urophycis brasilensis) exposed to a benzocaine bath solution were investigated. Cortisol and glucose levels 1 h after capture from the wild and on days 7 and 14 during the acclimatization period (20 days) were also determined. During the second week, cortisol levels reached to basal values (9 ng ml⁻¹). The use of benzocaine causes a significant increase in the erythrocyte number, in the concentration of hemoglobin and sodium and a decrease in chloride. Plasma cortisol and cholesterol levels were higher in fish exposed to the anesthetic, and glucose levels decreased significantly comparing with the control group, showing strong fluctuations between individuals in all the cases. These results show that the use of benzocaine causes an acute stress response that could be reverted quickly and it has to be considered during the evaluation of stress in fish.     

Effect of some repetitive factors on turbot stress response

The stress response of the turbot, Scopthalmus maximus (L.), to repetitive factors including netting, air exposure, blood sampling and hand-stripping, were tested using two different tank sizes as well as two blood sampling techniques. Exposure of juvenile fish to air for 1-4 min had no immediate effect on plasma cortisol concentrations or haematocrit values. Similarly, the serial netting of immature fish from tanks did not significantly modify plasma cortisol concentrations, haematocrit or osmolarity values. Hand-stripping of mature males was more disturbing than air exposure. The cumulative effect on plasma cortisol levels and osmolarity of stress factors such as netting, air exposure, blood sampling and stripping applied simultaneously to mature males in a 16 m3 tank and repeated twice daily for several days was recorded. The level of cortisol increased from 5 ng ml-1 to 300 ng ml-1 after 10 days of treatment, while an osmoregulatory imbalance and fish death were observed. Moreover, adaptation of fish to smaller tanks seemed to improve the increased plasma cortisol levels and death rate. Reduction in the number of stress factors applied greatly decreased both the range of physiological responses and the death rate. In order to avoid a cumulative stress response, handling of fish should therefore be reduced to a minimum.     

Association study of molecular polymorphisms in candidate genes related to stress responses with production and meat quality traits in pigs

The hypothalamic-pituitary-adrenal (HPA) axis exerts a large range of effects on metabolism, the immune system, inflammatory processes, and brain functions. Together with the sympathetic nervous system, it is also the most important stress-responsive neuroendocrine system. Both systems influence production traits, carcass composition, and meat quality. The HPA axis may be a critical target for genetic selection of more robust animals. Indeed, numerous studies in various species have demonstrated the importance of genetic factors in shaping the individual HPA axis phenotype, and genetic polymorphism can be found at each level of the axis, including hormone production by the adrenal cortices under stimulation by adrenocorticotropic hormone (ACTH), hormone bioavailability, or receptor and postreceptor mechanisms. The aim of the present experiment was to extend these findings to the brain neurochemical systems involved in stress responses. To this end, a number of candidate genes were sequenced for molecular polymorphisms and their association was studied with stress neuroendocrine and production traits in a genetically diverse population consisting of 100 female pigs from an advanced intercross (F10-F12) between 2 highly divergent breeds, Large White (LW) and Meishan (MS). The LW breed has a high production potential for lean meat and a low HPA axis activity, and the MS breed has low growth rate, fat carcasses—but large litters of highly viable piglets—and a high HPA axis activity. Candidate genes were chosen in the catecholaminergic and serotonergic pathways, in the pituitary control of cortisol production, among genes previously demonstrated to be differentially expressed in ACTH-stimulated adrenal glands from LW and MS pigs, and in cortisol receptors. Sixty new polymorphisms were found. The association study with carcass and meat quality traits and with endocrine traits showed a number of significant results, such as monoamine oxidase (MAOA) polymorphisms with growth rate (P = 0.01); lean content and intramuscular fat (P < 0.01), which are the most important traits for carcass value; dopamine receptor D3 (DRD3) with carcass composition (P < 0.05); and vasopressin receptor 1B (AVPR1B) with meat quality traits (P ≤ 0.05). The effect of these polymorphisms on neuroendocrine parameters (eg DRD3 and HPA axis or AVPR1B and catecholamines) indicates information regarding their biological mechanism of action.