Effect of octreotide on plasma concentrations of glucose, insulin, glucagon, growth hormone, and cortisol in healthy dogs and dogs with insulinoma

The inhibitory effect of the somatostatin analogue octreotide on the secretion of insulin could be used in the treatment of insulinoma. However, current information on the effectiveness of octreotide in dogs is conflicting. Therefore, the endocrine effects of a single subcutaneous dose of 50 microg octreotide were studied in healthy dogs in the fasting state (n=7) and in dogs with insulinoma (n=12). Octreotide did not cause any adverse effects. In healthy dogs in the fasting state, both plasma insulin and glucagon concentrations declined significantly. Basal (non-pulse related) GH and ACTH concentrations were not affected. A slight but significant decrease in the plasma glucose concentrations occurred. Dogs with insulinoma had significantly higher baseline insulin concentrations and lower baseline glucose concentrations than healthy dogs in the fasting state. Plasma glucagon, GH, ACTH, and cortisol concentrations did not differ from those in healthy dogs. Baseline plasma insulin concentrations decreased significantly in dogs with insulinoma after octreotide administration, whereas plasma concentrations of glucagon, GH, ACTH, and cortisol did not change. In contrast to the effects in the healthy dogs, in the dogs with insulinoma plasma glucose concentrations increased. Thus, the consistent suppression of plasma insulin concentrations in dogs with insulinoma, in the absence of an suppressive effect on counter-regulatory hormones, suggests that further studies on the effectiveness of slow-release preparations in the long-term medical treatment of dogs with insulinoma are warranted.     

急性冰水应激对犬血清甲状腺激素、NO及Na、K、Cl离子含量的影响

通过测定急性冰水应激时犬血清甲状腺激素、NO及Na、K、Cl离子含量的变化,来评价急性冰水应激对犬体内能量代谢、氧化应激状态及电解质平衡的影响。试验选取8只成年杂种犬,保定躯干浸于冰水混合物中(0~4)℃,使其进行冰水浴30 min。分别于处理前0.5 h(-0.5 h)及处理后0、0.5、1、3、7 h进行桡静脉采血2 mL,分离血清后测定其甲状腺激素(T3、T4)、一氧化氮(NO)及Na^+、K^+、Cl^-的含量。结果表明:与-0.5 h(处理前)相比,处理后各时间点犬血清T3含量无显著变化(P>0.05),与-0.5 h及0、3、7 h相比,血清T4含量在0.5 h时显著降低(P<0.05);血清NO含量在处理后各时间点均显著高于处理前0.5 h(P<0.05),且1、3、7 h显著高于0、0.5 h(P<0.05);与-0.5 h相比,处理后3 h血清Na^+含量显著升高(P<0.05),血清K^+含量处理后0 h显著高于1、3、7 h(P<0.05),血清Cl^-含量处理前后差异不显著(P>0.05)。研究表明,急性短期冰水应激会扰乱机体的能量代谢状态、降低T4含量,同时造成氧化应激损伤、使NO含量大量升高;引起血清Na、K离子平衡紊乱、含量升高,提示临床上人或动物发生冰水应激时应及时纠正机体能量代谢、氧化还原平衡和电解质的紊乱。     

Effect of 12-hour road transportation on physiological, immunological and haematological parameters in bulls housed at different space allowances

The effects of transporting Holstein Friesian bulls (n=72; bodyweight 403+/-3.5 kg) for 12h by road were examined. Adrenal, haematological and immune responses, body temperature and performance were recorded. The animals had been previously housed for 96 days at three space allowances (1.2, 2.7 or 4.2m(2) per bull). The bulls were allocated to one of two treatments: T (transport for 12h; n=16 per space allowance) and C (control; n=8 per space allowance). Basal cortisol plasma concentrations and interferon (IFN)-gamma production from cultured lymphocytes did not show any statistically significant difference (P>0.05) following the housing period. Removing bulls from their home pens and walking them to the pre-loading crush facility, loading onto the transporter, and unloading following the 12h road journey, significantly (P<0.001) increased plasma cortisol concentration. The bulls housed at 4.2m(2) had greater (P<0.05) plasma cortisol concentrations than bulls housed at 1.2m(2) at loading, unloading, or on return to the crush holding facility; those housed at 1.2m(2) had greater (P<0.05) plasma cortisol concentrations than bulls housed at 2.7 and 4.2m(2) in their home pens after transport. There was an increased (P<0.05) plasma cortisol response in the T than in the C bulls following adrenocorticotrophic hormone administration. Transport significantly reduced (P<0.05) IFN-gamma production, lymphocyte % and body weight and significantly increased (P<0.05) neutrophils, eosinophils, packed cell volume, red blood cell numbers and haemoglobin. In conclusion, housing bulls for 96 days in a range of space allowances did not affect basal cortisol response or immune function parameters. Whereas transport increased plasma cortisol and reduced the immune response in the short-term, the changes were transient and within normal physiological ranges, suggesting that 12h road transport had no adverse effect on welfare status over the longer term. Furthermore, transport of bulls housed at increased space allowance (4.2m(2)/bull) resulted in a greater plasma cortisol response, albeit still within normal physiological range.     

Effects of field bean (Vicia faba L. var. minor) dietary supplementation on plasma thyroid hormones, insulin, insulin-like growth factor-1 concentrations and mohair characteristics in growing Angora goat kids

Twenty-two Angora kids were used to study the effect of a dietary supplementation with field bean (Vicia faba L. var. minor) on hair follicle activity, mohair characteristics and plasma total thyroxine (T4), triiodothyronine (T3), insulin (INS) and insulin-like growth factor-1 (IGF-1) concentrations. At birth, their mothers were divided in two groups (S: supplemented, C: control), the S group being supplemented with 300 g/head/day of whole field bean. At weaning, diet of kids from S group was supplemented with 80 g/head/day of whole field bean. At weaning, secondary hair follicle activity (S: 0.91 ± 0.01, C: 0.84 ± 0.02, p < 0.01) and staple length (S: 5.82 ± 0.13 cm, C: 5.16 ± 0.14 cm, p < 0.001) were greater in the S group. At 155 days of age, secondary fibre diameter (S: 16.54 ± 0.35 μm, C: 18.09 ± 0.31 μm, p < 0.01) was higher in the C kids. Concentrations of total plasma T4 and T3 were higher (p < 0.001) in S (120 ± 12 and 4.87 ± 0.92 ng/ml respectively) than in C kids (92 ± 8 and 2.97 ± 0.77 ng/ml respectively). At weaning, T4 values were negatively correlated (p < 0.05) with the secondary fibre diameter and the T3/T4 ratio was positively correlated (p < 0.05) with the secondary to primary hair follicle ratio. At 155 days of age, both T3 and T3/T4 values were positively correlated (p < 0.01) with staple length. Plasma INS (0.11 ± 0.03 ng/ml) and total IGF-1 concentrations (232 ± 13 ng/ml) were not affected by diet. Improvements of diet quality in kids positively affected fibre diameter and length and follicle activity rate. We suggest that increased circulating thyroid hormones concentrations, but not those of INS and IGF-1, may contribute to the beneficial actions of nutritional supplementation on anatomical growth and mohair production of kids.     

Effect of age on serum chemistry profile, electrophoresis and thyroid hormones in beagle dogs two weeks to one year of age

Chemistry tests were conducted on serum from young Beagle dogs in order to deter mine the effect of age on these parameters. Blood was collected at regular intervals from 25 normal Beagle puppies (13 males and 12 females) at ages ranging from 2 weeks to 12 months. Serum chemistry profiles, protein electrophoresis and radioimmunoassays for thyroxine and triiodothyronine were included. Rapidly changing age related differences were observed in several parameters. Urea nitrogen, cholesterol, triglycerides, lactate dehydrogenase, thyroxine, glucose, gamma glutamyl transpeptidase, and total bilirubin values were elevated early in life, and decreased during the first 6 to 8 weeks, while alanine aminotransferase activity was low initially and increased during this period. Lactate dehydrogenase, thyroxine, gamma glutamyl transpeptidase, total bilirubin and alanine aminotransferase attained stability by 3 months, but the remaining parameters showed slight changes subsequently, gradually approaching adult values. More gradual age related changes were observed in other parameters. These included alkaline phosphatase, inorganic phosphorus and calcium values, which were higher in younger dogs, and creatinine, aspartate aminotransferase and total protein values, which were lower in younger dogs. Creatinine and aspartate aminotransferase values were stable by approximately 6 months; alkaline phosphatase, inorganic phosphorus, calcium and total protein values continued to change gradually up to 1 year.     

Effect in sheep of dietary concentrate content on secretion of growth hormone, insulin and insulin-like growth factor-I after feeding

This study was designed to examine the effects of the proportion of concentrate in the diet on the secretion of growth hormone (GH), insulin and insulin‐like growth factor‐I (IGF‐I) secretion and the GH‐releasing hormone (GHRH)‐induced GH response in adult sheep fed once daily. Dietary treatments were roughage and concentrate at ratios of 100:0 (0% concentrate diet), 60:40 (40% concentrate diet), and 20:80 (80% concentrate diet) on a dry matter basis. Mean plasma concentrations of GH before daily feeding (10.00–14.00 hours) were 11.4 ± 0.4, 10.1 ± 0.5 and 7.5 ± 0.3 ng/mL on the 0, 40 and 80% concentrate diet treatments, respectively. A significant decrease in plasma GH concentration was observed after daily feeding of any of the dietary treatments and these decreased levels were maintained for 8 h (0%), 12 h (40%) and 12 h (80%), respectively (P < 0.05). Plasma IGF‐I concentrations were significantly decreased 8–12 h and 4–16 h after the end of feeding compared with the prefeeding level in the 40 and 80% concentrate diet treatments, respectively (P < 0.05). GHRH injection brought an abrupt increase in the plasma GH concentrations, reaching a peak 10 min after each injection, but, after the meal, the peak plasma GH values for animals fed 40% (P < 0.05) and 80% (P < 0.01) concentrate diet were lower than that for roughage fed animals. The concentrate content of a diet affects the anterior pituitary function of sheep resulting in reduced baseline concentrations of GH and prolonged GH reduction after feeding once daily.     

The relationship between serum level of thyroid hormones,trace elements and antioxidant enzymes in dromedary camel (<Emphasis Type="Italic">Camelus dromedarius</Emphasis>)

Thyroid hormones might be able to regulate the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPX). The role of thyroid hormones in metabolic pathways and antioxidant enzyme activities are well known in many species. Nevertheless, there is no report describing probable relationship between thyroid hormones status, erythrocyte antioxidant enzymes and serum profiles of trace elements. This study was undertaken to investigate the relationship between these parameters in Iranian dromedary camels. Blood samples were taken from the jugular vein of 30 clinically healthy Iranian dromedary camels under aseptic conditions during 6 consecutive days of summer. The serum was analyzed for serum profile of thyroid hormones, trace elements, SOD and GPX activity. There were no significant differences in serum thyroid hormones, serum level of zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), selenium and antioxidant enzymes in different days (P > 0.05). There was a significant negative correlation between SOD and Fe (P < 0.01, r = -493). There was no significant correlation between other parameters. In case of copper deficiency likewise the present study, the copper was used to produce more SOD, so there was a decrease in Fe transportation, and it might be a cause of decrease in Fe amount. On the other hand, a relatively small quantity of Fe is present in tissue myoglobin, catalase, peroxidases, and cytochromes. So it might be another cause of decrease in Fe amount. The explanation for these finding is not possible at this moment and further investigations are needed to interpret these changes.     

Effects of heat stress on production,somatic cell score and conception rate in Holsteins

We examined the effects of heat stress (HS) on production traits, somatic cell score (SCS) and conception rate at first insemination (CR) in Holsteins in Japan. We used a total of 228 242 records of milk, fat and protein yields, and SCS for the first three lactations, as well as of CR in heifers and in first‐ and second‐lactation cows that had calved for the first time between 2000 and 2012. Records from 47 prefectural weather stations throughout Japan were used to calculate the temperature–humidity index (THI); areas were categorized into three regional groups: no HS (THI < 72), mild HS (72 ≤ THI < 79), and moderate HS (THI ≥ 79). Trait records from the three HS‐region groups were treated as three different traits and trivariate animal models were used. The genetic correlations between milk yields from different HS groups were very high (0.91 to 0.99). Summer calving caused the greatest increase in SCS, and in the first and second lactations this increase became greater as THI increased. In cows, CR was affected by the interaction between HS group and insemination month: with summer and early autumn insemination, there was a reduction in CR, and it was much larger in the mild‐ and moderate‐HS groups than in the no‐HS group.