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1.
Effects of stress on concentrations of cortisol and corticosteroid-binding globulin (CBG) in blood plasma and on glucocorticoid receptor concentrations in muscle cytosol were studied in pigs representing three Halothane (Hal) genotypes (NN, Nn, nn). At 12 wk of age, animals were divided into four groups: pigs subjected to transport (5 h in a truck), pigs treated with amperozide prior to transport, pigs not transported but treated with amperozide and pigs neither transported nor given amperozide. Animals were slaughtered the week they reached 100 kg live weight (3 mo later). The Hal gene showed no major influence on the variables studied except for cortisol concentrations (P = .06) measured directly after transport at 12 wk of age (NN = 66.8 nM, Nn = 61.4 nM, nn = 69.4 nM). However, the response in each Hal genotype differed, depending on whether or not the pigs had been exposed to transport. Two weeks after transport, NN pigs developed higher cortisol concentrations than untransported animals, whereas the response was reversed in nn animals; Nn pigs showed no difference in this regard. At slaughter, the effect of transport (12 wk of age) on cortisol and CBG was still apparent. In NN pigs cortisol and CBG concentrations were elevated (P less than or equal to .05, P = .08, respectively), whereas concentrations tended to be lower in nn pigs (P = .17, P = .07, respectively) when compared with untransported pigs. Transported pigs had lower receptor concentrations at slaughter (P less than or equal to .01) than untransported pigs. However, pigs given amperozide in connection with transport had a receptor concentration comparable to that in untransported pigs. Our study shows conclusively that transport stress had long-term effects on cortisol, CBG and glucocorticoid receptor concentrations. In addition, amperozide had long-term effects on cortisol and receptor concentrations.  相似文献   

2.
A study was conducted with 20 weaned barrows (14 d, 4.98 +/- 0.21 kg) to determine the effect of feeding spray-dried plasma (SDP) after weaning on the pig's stress response to a lipopolysaccharide (LPS) challenge. After weaning, pigs were fed a diet containing 0 or 7% SDP for 7 d. On d 6 after weaning, all pigs were nonsurgically fitted with a jugular catheter. On d 7 after weaning, the pigs were given i.p. injections of either saline or LPS (150 microg/kg BW) followed by serial blood collection every 15 min for a 3-h period. Following the 3-h blood collection, all pigs were killed and tissue was collected for mRNA analysis. Pig weight on d 7 after weaning was not affected by dietary treatment (P > 0.21). Pigs fed the diet with SDP had lower (P < 0.05) levels of hypothalamic corticotropin-releasing hormone (CRH) mRNA, pituitary gland CRH receptor mRNA, and adrenal gland adrenocorticotropin-releasing hormone (ACTH) receptor mRNA. Dietary treatment did not affect pituitary gland proopiomelanocortin (POMC) mRNA. No effect of LPS treatment was observed in any of the mRNA levels examined. For both serum ACTH and cortisol, there was a significant diet x LPS treatment interaction (P < 0.01) such that both the ACTH and cortisol responses to the LPS challenge were greater in the pigs fed the diet with SDP than in the pigs fed the diet without SDP. For pigs given the saline injection, diet did not affect basal serum cortisol concentration; however, basal serum ACTH concentration was lower in those pigs fed the diet with SDP (P < 0.0001). A diet x LPS treatment interaction (P < 0.024) was observed for adrenal gland mRNA expression for steroidogenic acute regulatory (StAR) protein such that the LPS-induced increase in StAR mRNA was greater in the pigs fed SDP than in pigs fed the diet without SDP. These results demonstrate that pigs fed a diet with SDP have an increased activation of the pituitary-adrenal axis following an LPS challenge compared to pigs fed a diet without SDP.  相似文献   

3.
苏钟Ⅰ系和Ⅱ系猪的氟烷基因及其对产肉性能的影响   总被引：1，自引：0，他引：1  
:对 3 0 1头瘦肉型新品系苏钟 系和 系仔猪进行氟烷测验 ,阳性率为 1 .3 3 %。随机抽取氟烷阴性猪 3 4头进行基因型检测 ,有 6头为杂合子 ,由此得知 NN、Nn和 nn3种基因型的频率分别为 81 .2 6%、1 7.4 1 %和 1 .3 3 %,N和 n2种基因的频率分别为 89.97%和 1 0 .0 3 %。对 3种基因型猪的肉质进行评定结果显示 ,4头氟烷阳性猪 ( nn)肉质最差 ,出现 3头严重 PSE肉和 1头轻度 PSE肉 ,而氟烷阴性猪 ( NN或 Nn)未发生 PSE肉。2 0头苏钟 系氟烷阴性猪用阳性公猪测交 ,对产出的 2 0 8头后代进行氟烷测验 ,共检出 4窝中的 2 1头阳性猪。对测交后代进行肥育性能和肉质测定 ,发现阳性猪的日增重和饲料报酬等较低 ,屠宰率、眼肌面积和瘦肉率较高 ,肉质较差  相似文献   

4.
A study was conducted to determine whether within-breed differences in adrenocortical response to exogenous adrenocorticotropin (ACTH) might be accounted for by differences in responsiveness of the adrenocortical cells per se. Large White x Landrace male pigs (n = 20) were used; 10 had high adrenocortical response to ACTH administration and 10 had low response. Five high and 5 low responders were euthanatized at 15 weeks of age, and the remaining 5 high and 5 low responders were euthanatized at 21 weeks of age. Adrenal glands were removed and weighed, and adrenocortical cells were dispersed by tryptic digestion and incubated for 2 hours with synthetic ACTH at concentrations ranging from 0.5 to 10,000 pg/ml. Samples were taken at 30-minutes intervals, and cortisol concentration was determined by use of a radioimmunoassay. Results indicate that for pigs of both age groups, high responders had heavier adrenal glands, with higher adrenocortical cell density and higher cell yield than did low responders. Synthetic ACTH had a stimulatory effect on dispersed porcine adrenocortical cells, as indicated by changes in cortisol concentration in vitro. Adrenocortical cells from high responders produced less cortisol, on a per-cell basis, than did those from low responders. However, when corrected for total cell yield, the potential cortisol production by each pair of adrenal glands was significantly (P less than 0.05) higher in the high responders than in the low responders. Thus, high-responding pigs have larger adrenal glands and higher adrenocortical cell density, which may result in higher output of cortisol after ACTH administration or exposure to stressors.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

5.
A study was conducted to determine whether differences in adrenocortical response to exogenous adrenocorticotrophin (ACTH) were an accurate reflection of an animal's perception of and response to stressful stimuli, or whether the pituitary gland might modulate adrenocortical responsiveness. Sixteen Large White x Landrace female pigs, of which 8 had high adrenocortical response to ACTH and the other 8 had low response, were administered IV a bolus of synthetic human corticotropin-releasing factor (hCRF) at dose rates ranging from 0.002 to 2 micrograms/kg of body weight. Blood samples were collected at known times for up to 2 hours after administration of hCRF. Plasma ACTH and cortisol concentrations were measured by radioimmunoassay. Results indicate that hCRF stimulated the pituitary gland of high- and low-responding pigs to secrete ACTH, which in turn stimulated the adrenal cortex to secrete cortisol. Plasma ACTH concentration, before or after hCRF administration, was not significantly different between the high and low responders. However, high-responding pigs had higher cortisol concentration after hCRF administration than did low-responding pigs. Thus, the differences in adrenocortical response to ACTH between the 2 groups of pigs were not attenuated by variation in pituitary response. It is concluded that adrenocortical responsiveness to ACTH is an accurate indicator of the perception of and the response to stress.  相似文献   

6.
In an effort to understand the relationship between muscle fiber type, live weight, genotype, and PSE development, enzyme-linked immunosorbent analyses were used to evaluate myosin heavy chain (MyHC) isoform content in the longissimus muscle of pigs differing in halothane gene status (nn, homozygous mutant; Nn, heterozygous; NN, homozygous normal) that were slaughtered at three different weights (100, 120 and 140 kg). Pigs carrying the n gene (Nn and nn) exhibited more IIB MyHC and less slow type I MyHC than those pigs free of the n gene, while NN pigs had greater amounts of IIAX MyHC. The relative abundance of IIB and IIAX MyHC in muscle of all pigs studied was strongly negatively correlated (r=−0.834). Heavier pigs (140 kg) had the greatest amounts of slow and IIA MyHC. Across all genotypes, the relative abundance of IIB MyHC and muscle pH at 45 min postexsanguination (pH45) was negatively correlated (r=−0.418). In addition, the relative amount of slow was positively correlated with pH45 (r=0.386). Because muscle of homozygous nn positive pigs exhibited similar IIB/slow MyHC ratios to that of heterozygous Nn pigs, yet less desirable pH45 values and ultimate meat quality scores argues against a role of MyHC content per se in contributing to PSE development. However, these data do not preclude that those pigs with greater amounts of IIB MyHC are more ‘susceptible’ to adverse pork quality development than those pigs with less IIB MyHC.  相似文献   

7.
Plasma pyruvate kinase (PK) and creatine kinase (CK) activities were increased significantly (P less than 0.001 and P less than 0.05, respectively) in homozygote halothane-reacting pigs (nn), compared with those activities in homozygote nonreacting pigs (NN). Pyruvate kinase activity was less variable within groups than was CK activity, allowing more effective discrimination between nn and NN geno-types. The PK and CK activities in plasma increase with age in halothane-reacting pigs and the nonreacting pigs. Enzyme activities in heterozygote (Nn) nonreacting pigs did not differ significantly (P greater than 0.05) from enzyme activities of homozygote (NN) nonreacting pigs. Although PK was better than CK in identifying stress-susceptible pigs, age-related effects and the failure to identify heterozygotes may restrict the use of plasma PK activity as a diagnostic test for the stress syndrome.  相似文献   

8.
The utility of a low dose (1 microgram/kg) synthetic ACTH challenge test in detecting moderate reductions in adrenocortical sensitivity in dogs was examined. First, the adrenocortical responses to an intravenous bolus of either 1 microgram/kg or 0.25 mg per dog of synthetic ACTH were compared in two groups of normal dogs. While plasma cortisol concentrations were similar in both groups 60 minutes after ACTH injection, dogs given 0.25 mg ACTH showed continued elevations in plasma cortisol concentrations at 90 and 120 minutes after ACTH injection. Later, the dogs previously tested with the 1 microgram/kg ACTH challenge were given a single intramuscular dose of prednisone (2.2 mg/kg) and retested with 1 microgram/kg of ACTH one week later. Plasma cortisol levels were significantly reduced after ACTH injection in dogs previously given prednisone demonstrating that a single intramuscular prednisone dose causes detectable adrenocortical suppression one week after administration. The 1 microgram/kg synthetic ACTH challenge test provides a sensitive means for evaluating adrenocortical suppression in dogs.  相似文献   

9.
The objectives of this study were first to show adrenocortical response to a long‐acting adrenocorticotropic hormone preparation (tetracosactide acetate zinc suspension) (ACTH‐Z) and its effect on adrenocortical function in beef cows ( Experiment 1 ) and second to apply the ACTH‐Z challenge in dairy cows based on cortisol concentrations in milk collected at routine milking ( Experiment 2 ). In Experiment 1 , four beef cows in luteal phase were challenged with ACTH‐Z, and plasma cortisol concentrations were determined for 48 h after the injection at 30‐min to 2‐h intervals. A rapid ACTH test was conducted 3 days before and 2 h after the completion of ACTH‐Z injection for 48 h to investigate the effect on adrenocortical function. Plasma cortisol concentrations increased significantly 30 min after ACTH‐Z injection (p < 0.001), and the high cortisol levels were maintained for approximately 10 h after the injection. In Experiment 2 , eight dairy cows were subjected to ACTH‐Z challenge 1–2 weeks and 4–5 weeks post‐partum. Blood and milk samples were taken at morning and afternoon milking. All the cows showed a significant increase in cortisol concentrations in plasma as well as in skim milk 8 h after ACTH‐Z injection 1–2 weeks and 4–5 weeks post‐partum (p < 0.001). There was a significant correlation between plasma and skim milk cortisol concentrations 8 h after ACTH‐Z challenge (r = 0.74, p < 0.001). The results obtained in this study suggest that elevated levels of plasma cortisol are maintained for approximately 10 h after ACTH‐Z treatment without adverse effect on adrenocortical function and a long‐acting ACTH‐Z challenge based on cortisol concentrations in milk, which were collected at the morning and the afternoon milking, can be a useful tool to monitor adrenocortical function in cows.  相似文献   

10.
The effect of ACTH administration on plasma cortisol concentrations in purebred and crossbred pigs was investigated. Pigs were given either 25 IU of ACTH or physiologic saline solution IM. Blood samples were collected immediately before and 1 hour after ACTH or saline solution administration. Administration of ACTH resulted in a significant (P less than 0.01) increase in plasma cortisol concentration compared with that resulting from administration of saline solution; mean values after ACTH administration were similar in both breed groups. In contrast, a fivefold range of differences was observed among individual pigs of the same age, sex, and body weight, irrespective of breed group. The type and magnitude of the adrenocortical response was consistent and repeatable in pigs over a 3-month period, suggesting that pigs have a consistent capacity for adrenocortical response to ACTH administration. Development of a dynamic test allowed the high and low responding extremes in a population to be detected. The most suitable dose of synthetic ACTH was established to be 50 IU, and the best time for blood sample collection was 60 minutes after ACTH administration. The classification of individual pigs as high or low responders was repeatable and was not affected by prior short-term exposure to ACTH.  相似文献   

11.
Effects of the halothane genotype and slaughter weight on texture of pork   总被引：4，自引：0，他引：4  
The objective of this study was to investigate the effects of the halothane (HAL) genotype, slaughter weight (SW), and the HAL x SW interaction on compositional and textural traits of raw and cooked pork. Pigs were bred to exhibit one of the three HAL genotypes (NN, Nn, and nn) with otherwise equivalent genomes. The nn halothane reactors are known to typically produce PSE pork, whereas NN pigs do not typically produce PSE pork. Pietrain x Large White gilts and boars, all with verified Nn genotype (by DNA test), were mated to obtain F2 littermates of the three HAL genotypes. These pigs were slaughtered at either 101 +/- 3 ("light") or 127 +/- 3 ("heavy") kg BW and were evaluated for longissimus muscle traits. The pH at .5 h after death (pH1) was 6.35, 6.13, and 5.68 in NN, Nn, and nn pigs, respectively. Sarcomere length was greater in nn than in NN and Nn pigs (1.94 vs 1.83 and 1.85 microm, respectively). Mechanical resistance was higher in nn than in NN pigs for both raw and cooked meat. Meat from nn pigs was judged by a trained panel to be less rough, more cohesive, harder, more fibrous, less granular, more elastic, and less easy to swallow than meat from NN pigs. For most traits under study, the heterozygotes were intermediate between the homozygotes but closer to NN than to nn pigs. Muscle from heavy pigs had longer sarcomeres and less moisture than muscle from light pigs. The n allele of the HAL gene unfavorably affects pork texture, and this effect is maintained throughout the range of 101 to 127 kg BW.  相似文献   

12.
Studies of human adrenocortical tumors (ATs) causing Cushing's syndrome suggest that hypersecretion of cortisol is caused by altered expression of steroidogenic enzymes and that steroidogenesis can only be maintained when there is expression of the ACTH receptor (ACTH-R). Here we report the screening for the mRNA expression of the ACTH-R, steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme, 3β-hydroxysteroid dehydrogenase, 21-hydroxylase (all in 38 cortisol-secreting ATs), 17α-hydroxylase, and 11β-hydroxylase (both in 28 cortisol-secreting ATs). Real-time PCR (RT-PCR) was applied in all samples and was compared with that in normal canine adrenal glands. Messenger-RNA encoding StAR, steroidogenic enzymes, and ACTH-R were present in both normal adrenal glands and cortisol-secreting ATs. The amounts of mRNA encoding StAR and enzymes of the steroidogenic cluster needed for cortisol production did not differ significantly between either adenomas or carcinomas and normal adrenal glands. The amount of mRNA encoding ACTH-R was significantly lower in carcinomas than in normal adrenal glands (P = 0.008). In conclusion, RT-PCR analysis revealed no overexpression of StAR and steroidogenic enzymes in canine cortisol-secreting ATs. Significant downregulation of ACTH-R in carcinomas might be associated with the malignant character of the AT.  相似文献   

13.
In two experiments, the effect of intensive housing on behavior and adrenocortical reactivity was studied in 68 castrated male German Landrace pigs. In both experiments, half of the pigs were tethered on a partially slatted floor without straw and half were kept, as controls, in groups on straw. Prior to the study, 32 of the pigs used in the first experiment were selected according to their reaction to halothane anesthesia; for the second experiment, 36 pigs were selected according to their adrenocortical response to azaperone-metomidate anesthesia. During the 4- to 6-wk experimental period, behavioral activity was observed and adrenocortical reactivity was analyzed after stimulation with synthetic ACTH(1–24), azaperone-metomidate anesthesia, insulin-induced hypoglycemia and neostigmine-atropine. Although no difference was found in general activity between groups, tethered pigs revealed a significantly higher cortisol increase after stimulation with ACTH(1–24) in both experiments and after insulin stimulation in the second experiment. Similarly, the area below the cortisol response curve after ACTH stimulation was significantly larger in tethered pigs in the second experiment. The individual reaction pattern was positively correlated between tests, indicating this pattern is a relatively constant, individual characteristic. In contrast, no correlation was found between behavior or adrenocortical reaction pattern and sensitivity to halothane. The results suggest that tethering on a partially slatted floor constitutes a chronic stressor which changes the adrenocortical response to an additional acute stressor. This increased reactivity is revealed most clearly after stimulation with ACTH(1–24) when individual responsiveness is taken into consideration.  相似文献   

14.
A mutation in the ryanodine receptor gene (RYR1) of the calcium release channel is responsible for increased stress susceptibility in pigs. In the present study, the relation of a mutation in RYR1 with the neuroendocrine (stress-related hormone) response and the immune defense represented by natural killer cell cytotoxicity (NKCC) during a 4-h restraint and recovery phase in 60 male pigs was investigated. Blood samples were collected from pigs previously divided into RYR1 genotypes (nn, Nn, NN), based on PCR amplification and restriction analyses. The blood samples collected during the restraint and recovery phases of the experiment were used to determine NKCC (51Cr-release assay), large granular lymphocyte number (hematologic method), and plasma concentrations of prolactin (PRL), GH, ACTH, and cortisol (COR) (by specific RIA). The greatest degree of NKCC response (P < 0.05) to restraint stress relative to controls was observed for the stress-susceptible homozygote group (nn). Measures of stress-related hormones were positively correlated with NKCC during the entire experimental period (P < 0.001 for all investigated hormones) in the nn group. Immunostimulatory effects in the early (0–60 min) phase of restraint were associated with increased hormone responses, especially PRL and GH. In the late (180–240 min) phase of stress and the recovery phase (480 min), a decrease in immune response was accompanied by an elevated COR response in all RYR1 genotypes. Moreover, divergent responses of both PRL (greatest in nn, P < 0.001) and GH (greatest in NN, P < 0.001) to the 4-h restraint were observed. Our results suggest that stress-susceptible RYR1-mutated homozygotes develop a greater level of immune defense, including cytotoxic activity of NK cells, and accompanied by more pronounced stress-induced changes in neuroendocrine response than stress-resistant heterozygous (Nn) and homozygous (NN) pigs.  相似文献   

15.
Canine hypercortisolism is most often caused by an ACTH-secreting pituitary adenoma (pituitary-dependent hypercortisolism; PDH). An interesting target for a selective medical treatment of PDH would be the receptor for ACTH: the melanocortin 2 receptor (MC2R). In this study we investigated whether two peptide compounds, BIM-22776 (#776) and BIM-22A299 (#299), are effective MC2R antagonists in vitro. Their effects on cortisol production and mRNA expression of steroidogenic enzymes, MC2R and melanocortin 2 receptor accessory protein (MRAP) were evaluated in primary adrenocortical cell cultures (n?=?8) of normal canine adrenal glands. Cortisol production stimulated by 50 nM ACTH was dose-dependently inhibited by #299 (inhibition 90.7?±?2.3% at 5 μM) and by #776 (inhibition 38.0?±?5.2% at 5 μM). The ACTH-stimulated mRNA expression of steroidogenic enzymes, MC2R and MRAP was significantly inhibited by both compounds, but most potently by #299. These results indicate that canine primary cell culture is a valuable in vitro system to test MC2R antagonists, and that these compounds, but especially #299, are effective MC2R antagonists in vitro. To determine its efficacy in vivo, further studies are warranted. Antagonism of the MC2R is a promising potential treatment approach in canine PDH.  相似文献   

16.
Angora goats do not cope well with stress compared with goats of other breeds. Our hypothesis that this involves subclinical primary hypoadrenocorticism associated with low cortisol release in response to ACTH stimulation was tested by measuring adrenocortical response (plasma cortisol) in six Spanish (37 +/- 2 kg BW) and six Angora wethers (39 +/- 3 kg BW) under simulated acute and chronic ACTH challenges. In Exp. 1 (acute ACTH challenge), wethers were dosed i.v. with high (2.5 IU/kg BW) or low (.4 IU/kg BW) quantities of ACTH. In Exp. 2 (chronic ACTH challenge), ACTH at the rate of .015 IU/(kg BW x min) or saline (.15 M NaCl) was infused i.v. at 15 mL/h for 6 h. The mean baseline plasma cortisol concentration before ACTH stimulation was similar (P > .05) between Angora and Spanish goats in Exp. 1 (averaged over days) and in Exp. 2. The cortisol concentration response area (ng/ (mL x min) x 10(-3)) above the baseline was similar (P > .05) between Angora and Spanish goats during low (7.6 +/- .5 and 9.0 +/- 1.7, respectively) and high (12.8 +/- 1.0 and 16.0 +/- 1.8, respectively) levels of acute ACTH challenge (Exp. 1) and during chronic ACTH challenge (45.1 +/- 5.9 and 41.8 +/- 7.3, respectively; Exp. 2). In conclusion, these data indicate that, under the conditions of this study, adrenocortical responsiveness to ACTH stimulation is not different between Angora and Spanish goat wethers and, thus, may not contribute to stress susceptibility in Angora goats.  相似文献   

17.
通过猪毛检测丹麦长白猪氟烷基因的变异   总被引：11，自引：2，他引：9  
采集５６头丹麦长白猪（其中１头为１周龄的仔猪，２６头种公猪，２９头种母猪）猪毛样品，粗提ＤＮＡ，进行ＰＣＲ扩增，得到６５９ｈｐ在氟烷基因中（即兰尼定受体基因）中第１８４３个碱基的异片段，经过ＨｈａＩ酶切和电泳来检测氟烷基的变异，即其基因型，结果表明，（１）５６头长白猪中，阳性猪（ｎ／ｎ）１头占１．７９％，杂合子猪（Ｎ／ｎ）为１８头，占３２．１４％，阴性猪（Ｎ／Ｎ）为３７头，占６６．０７％杂合子数实  相似文献   

18.
We evaluated the effect of maternal obesity before and throughout gestation on offspring hypothalamic-pituitary-adrenal axis function. Multiparous Rambouillet by Columbia crossbred ewes were fed either 100% of National Research Council (NRC) recommendations (control, C) or 150% of NRC recommendations (obese, OB) from 60 d before mating until lambing. Ten lambs born to OB ewes (five males and five females), and eight lambs born to C ewes (three male and five female) were studied. From delivery to weaning lambs were maintained with their mothers, who were all fed 100% NRC recommendations. After weaning, all lambs were group housed and fed the same diet to meet NRC requirements. At 19 mo of age lambs were placed in individual pens and fed a pelletized diet to meet maintenance requirements. Jugular vein catheters were placed and 2 d later lambs received an intravenous (i.v.) adrenocorticotropic hormone (ACTH) challenge followed by an i.v. corticotropin-releasing hormone (CRH)/arginine vasopressin (AVP) challenge 1 d later. Thirty d later offspring were again catheterized and placed into metabolism crates for 2 d before receiving an isolation stress test. ACTH and cortisol responses to the isolation stress test and CRH/AVP challenge and cortisol responses to ACTH challenge were determined. Cortisol was quantified via radioimmunoassay and ACTH was quantified using an Immulite 1000; both were analyzed using repeated measures using the MIXED procedure of SAS. Offspring from OB ewes had elevated basal plasma ACTH and cortisol compared with C offspring before all three challenges (P < 0.05). Offspring from OB mothers tended (P = 0.06) to have a greater ACTH response after an i.v. CRH/AVP injection than offspring from C mothers (12,340 ± 1,430 vs 8,170 ± 1,570 area under the curve, respectively). Cortisol response to the CRH/AVP and ACTH challenges was not influenced by maternal nutrition (P = 0.46) and averaged 4.77 ± 0.2 μg/dL and 1.94 ± 0.01 μg/dL, respectively. The ACTH response following the isolation stress test was also similar (P = 0.82) for OB and C offspring (147 ± 20 pg/mL), and cortisol response during the isolation stress test was similar between C and OB offspring (P = 0.64, 5.25 ± 0.3 μg/dL). These findings suggest that maternal obesity before and during gestation does not affect stress responses by the offspring, but has an impact on hypothalamic-pituitary-adrenal sensitivity. The lack of differences in cortisol release under the influence of difference concentrations of ACTH during the CRH/AVP challenge could indicate adrenal dysfunction in OB offspring.  相似文献   

19.
Behavior and pituitary-adrenal function in large white and Meishan pigs   总被引：5，自引：0，他引：5  
Six-wk-old piglets of both sexes from European Large White (LW, n = 36) and Chinese Meishan (MS, n = 24) breeds were individually exposed to a novel environment, a stressful stimulation. Behavioral and pituitary-adrenal reactivity were investigated. When compared with LW, MS pigs displayed low locomotion (18.5 ± 2.2 vs. 41.0 ± 3.8 squares crossed/10 min; P < 0.0001), and defecation scores (0.58 ± 0.15 vs. 4.86 ± 0.37 fecal boli; P < 0.0001). Basal concentrations of cortisol were higher in MS (96.1 ± 1.1 vs. 44.9 ± 1.1 ng/ml; P < 0.0001), although no differences between breeds were found in basal concentrations of adrenocorticotropic hormone (ACTH). In response to novel environment exposure, the ACTH increase was greater in LW than in MS, but the cortisol response was not different on a log scale. To further investigate the pituitary-adrenal differences between the two breeds, the 24-hr profile of ACTH and cortisol plasma concentrations, a corticotropin-releasing factor (CRF) and a coupled dexamethasone-ACTH test were studied. Five castrated male 9-wk-old piglets from each breed were fitted surgically with a jugular vein catheter. A classic marked circadian rhythm of cortisol and a weak nycthemeral variation of ACTH were found. Cortisol concentrations were approximately twice higher in MS exclusively during the early light phase (from 0800–1200 hr) of the cycle, but no significant interbreed difference was found in the circadian rhythm of ACTH. Administration of CRF (1 μg/kg iv) induced the same significant increase in plasma ACTH and cortisol concentrations in both breeds. Administration of ACTH (10 μg/kg iv) increased significantly cortisol concentrations and revealed no difference in plasma cortisol response to ACTH. These data suggest that the hypercortisolism of MS pigs is of adrenal origin, and related to extrapituitary factors that control the adrenal sensitivity during the light phase of the diurnal cycle.  相似文献   

20.
The serum cortisol responses of 10 normal cats to natural adrenocorticotrophic hormone (ACTH) gel and synthetic ACTH (cosyntropin) were evaluated and compared. Following administration of either ACTH gel or cosyntropin, mean serum cortisol concentrations increased significantly (P less than 0.05) within 30 minutes and reached a maximal response (2.5 to 10 times basal values) at 90 minutes. The time to reach peak serum cortisol concentrations was variable, however, and occurred sooner after cosyntropin (30 to 60 minutes) than after ACTH gel administration (90 to 180 minutes). While ACTH gel tended to produce a prolonged cortisol response, the effects of cosyntropin were more transient, with serum cortisol concentrations returning to normal range within three hours after injection. Results of this study indicate that the administration of either ACTH gel or cosyntropin consistently produces an adequate adrenocortical response in the cat. Based on the time response studies, post ACTH cortisol samples should be collected 60 to 90 minutes after cosyntropin or 90 to 120 minutes after ACTH gel injection to ensure detection of peak adrenocortical response with either ACTH preparation.  相似文献   

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