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1.
Breed differences for weight (CW), height (CH), and condition score (CS) were estimated from records (n = 12,188) of 2- to 6-yr-old cows (n = 744) from Cycle IV of the U.S. Meat Animal Research Center's Germplasm Evaluation (GPE) Program. Cows were produced from mating Angus and Hereford dams to Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese, and Salers sires. Samples of Angus and Hereford sires were 1) reference sires born from 1962 through 1970 and 2) 1980s sires born in 1980 through 1987. The mixed model included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and breedgroup as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as a linear covariate. The model for CH excluded PL. Random effects were additive genetic and permanent environmental effects associated with the cow. Differences among breed groups were significant (P < 0.05) for all traits and were maintained through maturity with few interchanges in ranking. The order of F1 cows for weight was as follows: Charolais (506 to 635 kg for different ages), Shorthorn and Salers, reciprocal Hereford-Angus (HA) with 1980s sires, Nellore, HA with reference sires, Galloway, Piedmontese, and Longhorn (412 to 525 kg for different ages). Order for height was as follows: Nellore (136 to 140 cm), Charolais, Shorthorn, Salers, HA with 1980s sires, Piedmontese, Longhorn, Galloway and HA with reference sires (126 to 128 cm). Hereford and Angus cows with reference sires were generally lighter than those with 1980s sires. In general, breed differences for height followed those for weight except that F1 Nellore cows were tallest, which may in part be due to Bos taurus-Bos indicus heterosis for size. 相似文献
2.
Data from topcross cows (n = 468) from six breeds of sire (Angus, Brahman, Hereford, Pinzgauer, Sahiwal, Tarentaise) and two breeds of dam (Angus and Hereford) of Cycle III of the Germplasm Evaluation (GPE) program at the U.S. Meat Animal Research Center (MARC) comprising cow weight (CW, n = 9,012), height (CH, n = 9,010), and condition score (CS, n = 8,991) recorded in four seasons per year from 2 to 6 yr of age were used to estimate breed-group differences. The mixed models included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and breed group as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as a linear covariate. Model for CH excluded PL. Random effects were additive genetic and permanent environmental effects. Differences among breed-groups were significant for all traits for different ages and were maintained across ages, with few interchanges in ranking through maturity. Cows with Sahiwal sires were lightest (392 to 479 kg), whereas Hereford-Angus (HA) reciprocal-cross cows were shortest (119 to 123 cm) at each age. Cows with Brahman sires were heaviest and tallest among breed groups at all ages, exceeding HA cows by 19 to 24 kg and 9 to 10 cm, respectively. Cows with Pinzgauer and Tarentaise sires were intermediate for weight and height and interchanged ranking across ages. Differences in weight due to differences in condition seemed to be of small magnitude because adjustment for condition score did not affect rankings of breed groups across ages. Important changes for mature size of cows can be achieved by breed substitution with the breeds of sires used in this study. 相似文献
3.
Data from Angus, Hereford, and top-cross cows (n = 641) from 2- to 8-yr-old daughters of seven breeds of sires included in Cycle II of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center, comprising cow weight (CW, n = 15,698), height (CH, n = 15,676), and condition score (CS, n = 15,667), were used to estimate breed-group differences. Data were recorded in four seasons of each year (1975 to 1982). The mixed model included cow age, season of measurement, and their interactions, year of birth, pregnancy-lactation code (PL), and breed-group as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as covariate. The model for CH excluded PL. Random effects were additive genetic and permanent environmental effects. Differences among breed-groups were significant for all traits at different ages and were maintained across ages, with few interchanges in ranking through maturity. Cows were ranked (by breed of sire) in the following order for weight: Red Poll (lightest), Hereford-Angus (reciprocal), Braunvieh, Gelbvieh, Maine Anjou, and Chianina (heaviest). In general, cows sired by breeds of British origin were lighter and shorter than those of continental origin. Differences in weight due to differences in condition seemed to be of small magnitude because making an adjustment for condition score did not affect rankings of breed groups across ages. Differences among breed groups for height were consistent with differences for weight. Cows from Chianina sires were taller than Hereford-Angus cows by 14 to 15 cm across ages. In this study, breed of sire effects were significantly different for the mature size of their daughters. 相似文献
4.
5.
Breed means and differences for weight (CW, n = 19,851), height (CH, n = 14,553), and condition scores (CS, n = 19,536) recorded in four seasons per year were evaluated for 881 cows ranging from 2 to 7 yr of age from Cycle I of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. Cows were straightbred Herefords and Angus and topcrosses from mating of Hereford, Angus, South Devon, Jersey, Simmental, Limousin, and Charolais sires to Hereford and Angus dams. The model included cow age, season of measurement, and their interactions, with year of birth, pregnancy-lactation (PL) code, and breed group as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as covariate. Model for CH excluded PL. Random effects were additive genetic and permanent environmental effects. Data were analyzed by REML. Differences due to breeds of sire were significant for all traits. Differences were generally maintained across ages, with few interchanges in ranking through maturity. Rankings were in the following order: Jersey (lightest and shortest), Hereford-Angus (and reciprocal), Limousin, South Devon, Simmental, and Charolais (heaviest and tallest). The only exception was that Limousin-sired cows were heavier than South Devon-sired cows after 5 yr of age. Cows sired by breeds of British origin tended to be lighter than breeds of continental European origin. Adjustment for condition score changed estimates of breed differences. Rankings of breed groups, however, were generally the same for actual weight and weight adjusted for condition score. Results indicated that the part of the differences in weight due to differences in condition were of small magnitude. Differences tended to increase when adjusted for condition score, especially in contrasts of continental vs British breeds. Differences among breed groups for height followed differences for weight closely. 相似文献
6.
Three projects recently funded by the American Veterinary Medical Association (AVMA) through the National Commission on Veterinary Economic Issues (NCVEI) focused on the veterinary school applicant pool, leadership skills in the veterinary profession, and a veterinary teaching hospital business model, respectively. The Skills, Knowledge, Aptitude, and Attitude (SKAs) Colloquium was designed to present the results of these three projects, to discuss their importance for the future of the veterinary profession, and to develop action plans accordingly. In all, 24 veterinary colleges were represented at the workshop and a total of 72 attendees participated, achieving a broad representation of the veterinary profession ( both academic and non-academic). Through an orchestrated combination of general sessions and facilitated small group discussions, recommendations for implementation and initial action plans for next steps were developed. From these, a list of potential AAVMC follow-up activities was developed, including advocating and facilitating programs across schools to engage and educate faculty regarding the results of these projects; developing realistic information on careers in veterinary medicine; organizing an AAVMC leadership consortium; working toward further development and implementation of the veterinary teaching hospital (VTH) business model; coordinating and sponsoring a national forum on the future of the VTH; reviewing admissions processes; integrating leadership into veterinary curricula; and organizing opportunities for faculty development in leadership. 相似文献
7.
K Reifenberg M Stahl U L?sch 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(3):191-198
A simple two step procedure for the isolation of caprine, ovine, bovine, equine, canine, porcine and human peripheral blood granulocytes is described. After enrichment of granulocytes by centrifugation, contaminating erythrocytes are lysed hypotonically. Recovery, purity, and viability of the granulocyte suspensions are determined. FACScan analysis of the cell suspensions measuring cellular size by forward and sideward light scatter is compared with the corresponding analysis of whole blood leukocytes. Constituencies of the isolated cell suspensions and loss of granulocyte subpopulations through isolation procedure is discussed with regard to granulocyte function assays. 相似文献
8.
Objective Human corneal cells have detectable levels of TLRs 1‐10. TLRs 2 and 4 are the major corneal receptors, recognizing the PAMPs associated with fungal invasion in humans. The conjunctiva and limbus contain TLRs 2, 4, and 9. Our purpose was to determine the expression of TLRs 2, 3, 4, 6, 9, and MD‐2 in the normal equine cornea, conjunctiva, and limbus. Methods Corneal, limbal, and conjunctival tissues were collected from seven euthanized horses having no evidence of ocular disease. RNA extraction with DNase‐1 digestion was performed followed by RT‐PCR to determine expression of TLRs 2, 3, 4, 6, 9, and MD‐2. Products were resolved by electrophoresis on 1.5% agarose gels and visualized using ethidium bromide staining. Results Expression of TLRs 2, 3, 4, 6, 9, and MD‐2 was present in the cornea, limbus, and conjunctiva of each horse, except one horse, where TLR3 expression was unable to be demonstrated in the dorsal and ventral conjunctiva. Conclusions Confirming the expression of TLRs in equine ocular tissues is an initial step in identifying how they play a role in infectious keratitis, particularly fungal. The results further support the use of equine ocular tissues as a model for human fungal keratitis. Studies of the TLR expression together with their cytokine profile induced during equine fungal keratitis may help further clarify the pathogenesis of the disease and possibly lead to the development of new treatment protocols for both equines and humans. 相似文献
9.
Inflammation of the bile ducts is common in cats. This review article reports on what is currently known about the various types of cholangitis (i.e., cholangitis caused by liver flukes, neutrophilic cholangitis, and lymphocytic cholangitis). Treatment is available for cholangitis caused by liver flukes and for neutrophilic cholangitis, and the prognosis is good. However, the cause of lymphocytic cholangitis is not known and there is currently no evidence-based therapy. Several causes are mentioned in the literature, but more research is needed in order to establish the cause of this disease and to develop an appropriate therapy. 相似文献
10.
Genetic parameters among weight, prolificacy, and wool traits of Columbia, Polypay, Rambouillet, and Targhee sheep 总被引：2，自引：0，他引：2
Genetic parameters for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models for prolificacy, weight, and wool traits. All bivariate analyses included a covariance between additive genetic effects for the two traits plus appropriate additional covariances. Number of observations by breed ranged from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for weight traits, and from 4,603 to 34,746 for wool traits. Heritability estimates ranged from .03 to .11 for prolificacy traits (litter size at birth and litter size at weaning), from .09 to .26 for weight traits (birth weight and average daily gain), and from .25 to .53 for wool traits (fleece weight, fleece grade and staple length). Estimates of direct genetic correlations among prolificacy and among weight traits were positive and ranged from .58 to 1.00 and .18 to 1.00, respectively. Estimates of direct genetic correlation between fleece weight and staple length were positive (.50 to .70) but were negative between fleece weight and fleece grade (-.60 to -.34) and between staple length and fleece grade (-.72 and -.40). Prolificacy and wool traits were essentially uncorrelated. Weight and prolificacy traits were slightly positively correlated. Weight traits had a moderate positive direct genetic correlation with fleece weight and staple length, but were uncorrelated with fleece grade. These estimates of genetic parameters between prolificacy, weight, and wool traits can be used to construct multiple-trait selection indexes for dual-purpose sheep. 相似文献
11.
Serologic prevalence of toxoplasmosis in cattle, sheep, goats, pigs, bison, and elk in Montana 总被引：2，自引：0，他引：2
J P Dubey 《Journal of the American Veterinary Medical Association》1985,186(9):969-970
Serum samples from 2,539 cattle, 649 sheep, 123 goats, 413 pigs, 93 bison, and 56 elk from Montana were examined for antibody to Toxoplasma gondii in the Sabin-Feldman dye test or the modified agglutination test (MAT). Cattle, bison, and elk serum samples were treated with 0.2 M-mercaptoethanol before examination in MAT. In the dye test, 13.2% of sheep, 5.0% of pigs, and 22.7% of goats had antibody at a dilution of greater than or equal to 1:16. In the MAT, 3.2% of cattle, 3.1% of bison, and none of the elk were positive at a dilution of greater than or equal to 1:128. 相似文献
12.
In experiment 1, 6 pregnant mares received a concentrate that contained a trace mineral premix that provided 14.3 mg Cu, 40 mg Zn, 28 mg Fe, 28 mg Mn, 0.08 mg Co, 0.16 mg I, and 0.16 mg Se/kg concentrate (group A). Seven mares received the same concentrate plus 502 mg Zn and 127 mg Cu once daily (group B). No differences (P > .05) in foal growth data, or Cu, Zn, and Fe concentrations of mare milk, mare serum, or foal serum were observed. In experiment 2, 6 pregnant mares received the same concentrate as group A (group C), and 8 mares received the same concentrate fortified with 4× the trace mineral premix (group D). Group C mares had higher serum Zn concentration at 1 day (P < 0.01) and 56 days (P < 0.04). Group C mares had higher milk Fe concentration at 28 days (P < .01), and group D mares had higher milk Cu concentration at 56 days (P < .01). Group C foals had higher serum Cu concentration at 14 days (P < .03). The results from this study provide no evidence to indicate that supplementing late gestating and lactating mares with higher dietary trace mineral levels than those recommended currently by NRC has any influence on foal growth and development, or on the Cu, Zn, and Fe concentrations of the mare milk, mare serum, or foal serum. 相似文献
13.
建立了同步测定沙咪珠利中甲醇、乙醇和甲苯残留溶剂的气相色谱法。采用DB-WAX（30m×0．25mm×0．25μm）毛细管柱,程序升温,初始60℃,保持4min,50℃／min升至80℃,保持1min。再以100℃／min升至200℃。保持4min;载气为氮气,直接进样,测定残留溶剂含量。甲醇、乙醇和甲苯线性范围分别为31．68～506．8、18．96～758．4、8．64～138．7μg/mL（R^2：0．9958～0．9971）,定量限分别为2．091、1．564、0．572μg／kg,精密度RSD均小于5％,平均回收率为99．87％-100．39％。采用气相色谱方法可同时测定沙咪珠利中残留的甲醇、乙醇和甲苯的含量,方法简便准确。 相似文献
14.
Stillbirths, mummies, abortions, and early embryonic death have a substantial impact on the profitability of a farm in both endemic and epidemic conditions. Fetal death is highly dependent on stage of gestation. Implantation occurs around day 14 postmating in sows, and fetal death of an entire litter at this time usually results in a regular return to service. If more than four embryos remain alive, the sow may go on to farrow normally. If fetal death occurs after implantation but before calcification (around 35 days gestation), the sow will either return to estrus at an irregular interval or will farrow a normal litter of reduced size. Although fetuses are normally resorbed prior to calcification, fetal death after that stage of development leads to mummification. Abortions are more directly related to maternal control of pregnancy than fetal failure. Stillbirths are those pigs that appear normal at birth but have lungs that do not float in water. Causes of fetal death can be divided into infectious and noninfectious categories. Infectious causes perhaps are overemphasized but are certainly important in epidemic situations. Some infectious causes of fetal death are primarily systemic maternal pathogens, whereas others may attack the fetus and/or placenta, directly such as PPV, PEV, PRV, SIRS virus, and Leptospira sp. Several other infectious agents have been associated with fetal death. Noninfectious causes of stillborns, mummies, abortions, and early embryonic death are most common in endemic situations. Most stillbirths are due to difficulty at or around parturition, primarily extended duration causing fetal anoxia. Environmental factors such as increased ambient temperature and seasonal infertility affect death rates, as do specific individual sow characteristics, nutritional factors, and toxicities. The causes of stillborns, mummies, abortions, and early embryonic death are often difficult to ascertain, but the potential rewards make investigation efforts worthwhile. 相似文献
15.
Objective Guinea pigs have a very low threshold of corneal sensitivity and at the same time nearly no reflex tearing compared to dogs, cats, and horses. The question arose whether there is a general correlation between corneal sensitivity and the quantity of reflex tearing. Animals studied Totally 160 animals of 8 different species (20 animals per species) were investigated. Procedures The corneal touch threshold (CTT) was measured with a Cochet–Bonnet esthesiometer. The palpebral fissure length (PFL) was measured with a calliper ruler. The Schirmer tear test (STT) was modified by adapting the width of the STT strip to the PFL of every species. For the STT II, 0.4% oxybuprocaine was applied. Results Corneal touch threshold: Cows (1.67 g/mm2), horses (1.23 g/mm2), sheep (1.13 g/mm2), goats (1.44 g/mm2), dogs (2.16 g/mm2), and cats (1.33 g/mm2) show similar CTT values. In contrast, rabbits (6.21 g/mm2) and guinea pigs (7.75 g/mm2) show a significantly lower CTT. Tear Production Difference STT I ? STT II: Rabbits have the greatest decline in tear production with 38.4%, followed by sheep (33.3%), dogs (31.1%), cats (24.7%), cows (23.7%), horses (18.0%), and goats (14.0%). Guinea pigs have no decline, but a slight increase of ?16.0%. Correlation CTT and STT II ? STT I Difference: Pearson’s correlation coefficient shows a small, but significant correlation. The coefficient of determination can only forecast a value with 7.1% certainty. Conclusions The high variance and low reproducibility of results suggest that the measuring devices are inappropriate to assess the evaluated parameters. Therefore, no assured correlation between the corneal sensitivity and the quantity of reflex tearing could be found. 相似文献
16.
Comparative pharmacokinetics of enrofloxacin in mice, rats, rabbits, sheep, and cows. 总被引：4，自引：0，他引：4
M A Bregante P Saez J J Aramayona L Fraile M A Garcia C Solans 《American journal of veterinary research》1999,60(9):1111-1116
OBJECTIVE: To compare pharmacokinetic variables of enrofloxacin (ENR) after IV administration in mice, rats, rabbits, sheep, and cows and to perform allometric analysis of ENR. ANIMALS: 47 mice, 5 rats, 5 rabbits, 5 sheep, and 5 cows. PROCEDURE: Serially obtained plasma samples were assayed for ENR concentration, using high-performance liquid chromatography. In vitro plasma protein binding was determined by ultrafiltration. Plasma ENR concentration versus time curves were fitted by use of nonlinear least-squared regression analysis. Pharmacokinetic variables were correlated further with body weight. RESULTS: In all species studied, the best fit was obtained for a two-compartment open model; ENR half-life ranged from 89 minutes in mice to 169 minutes in cows. Volume of distribution was large in all species studied, with values ranging from 10.5 L/kg in mice to 1.5 L/kg in sheep. Body clearance ranged from 68.1 ml/min/kg for mice to 4.6 ml/min/kg for sheep. Unbound ENR was found to be (mean +/- SD) 58+/-2, 50+/-6, 50+/-2, 31+/-2, and 40+/-3% in plasma of mice, rats, rabbits, sheep, and cows, respectively. The only pharmacokinetic variables that could be correlated with body weight were elimination half-life, clearance, and volume of distribution. Allometric exponents denoting proportionality of half-life, body clearance, and volume of distribution with body weight were 0.06, 0.82, and 0.90, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: An allometric approach could provide a suitable method for determining a scale for ENR pharmacokinetics among various mammalian species. This would faciliatate the administration of appropriate doses of ENR to all animals. 相似文献
17.
Nadine Pa?lack Barbara Mainzer Monika Lahrssen-Wiederholt Helmut Schafft Richard Palavinskas Angele Breithaupt Jürgen Zentek 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(1):57-66
This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations. 相似文献
18.
《Domestic animal endocrinology》1998,15(5):333-344
Gonadotropin secretion by the pituitary gland is under the control of luteinizing hormone-releasing hormone (LHRH) and the putative follicle stimulating hormone-releasing factor (FSHRF). Lamprey III LHRH is a potent FSHRF in the rat and seems to be resident in the FSH controlling area of the rat hypothalamus. It is an analog of mammalian LHRH and may be the long sought FSHRF. Gonadal steroids feedback at hypothalamic and pituitary levels to either inhibit or stimulate the release of LH and FSH, which is also affected by inhibin and activin secreted by the gonads. Important control is exercised by acetylcholine, norepinephrine (NE), dopamine, serotonin, melatonin, and glutamic acid (GA). Furthermore, LH and FSH also act at the hypothalamic level to alter secretion of gonadotropins. More recently, growth factors have been shown to have an important role. Many peptides act to inhibit or increase release of LH and the sign of their action is often reversed by estrogen. A number of cytokines act at the hypothalamic level to suppress acutely the release of LH but not FSH. NE, GA, and oxytocin stimulate LHRH release by activation of neural nitric oxide synthase (nNOS). The pathway is as follows: oxytocin and/ or GA activate NE neurons in the medial basal hypothalamus (MBH) that activate NOergic neurons by alpha1 (α1) receptors. The NO released diffuses into LHRH terminals and induces LHRH release by activation of guanylate cyclase (GC) and cyclooxygenase. NO not only controls release of LHRH bound for the pituitary, but also that which induces mating by actions in the brain stem. An exciting recent development has been the discovery of the adipocyte hormone, leptin, a cytokine related to tumor necrosis factor (TNF) α. In the male rat, leptin exhibits a high potency to stimulate FSH and LH release from hemipituitaries incubated in vitro, and increases the release of LHRH from MBH explants. LHRH and leptin release LH by activation of NOS in the gonadotropes. The NO released activates GC that releases cyclic GMP, which induces LH release. Leptin induces LH release in conscious, ovariectomized estrogen-primed female rats, presumably by stimulating LHRH release. At the effective dose of estrogen to activate LH release, FSH release is inhibited. Leptin may play an important role in induction of puberty and control of LHRH release in the adult as well. 相似文献
19.
Equine endotoxemia: cardiovascular, eicosanoid, hematologic, blood chemical, and plasma enzyme alterations 总被引：1，自引：0，他引：1
D S Ward J F Fessler G D Bottoms J Turek 《American journal of veterinary research》1987,48(7):1150-1156
Ponies with electromagnetic blood flow transducers implanted around the main pulmonary and left main coronary arteries, were used to evaluate effects of chronic sublethal endotoxin on cardiac output (CO), stroke volume, and left coronary blood flow (LCBF). Plasma thromboxane (TX), as indicated by TXB2, prostacyclin as indicated by 6-keto-prostaglandin (PG) F1 alpha, and hematologic and blood chemical values also were evaluated. Over 24 hours, 2 groups of ponies were given progressively increasing IV and intraperitoneal doses of Escherichia coli lipopolysaccharide (LPS) at 0, 6, 12, and 18 hours. Group 1 was not treated and group 2 was treated with flunixin meglumine, before each LPS insult. Initial LPS inoculation in group 1 led to 10-fold increases in TXB2 and 6-keto-PGF1 alpha values by 30 and 90 minutes, respectively. These eicosanoid values returned to base line by 6 hours after each insult. Although repeated LPS injections stimulated recurring high plasma concentrations of 6-keto-PGF1 alpha, TXB2 production became less with each successive LPS insult. Cardiac output decreased to 55% to 60% of base-line values in association with increased 6-keto-PGF1 alpha values. Left coronary blood flow could not be evaluated accurately. Severe lactic acidosis developed in group 1. Group-2 ponies remained clinically normal, indicating protection of cardiovascular function and peripheral perfusion with flunixin meglumine. Seemingly, flunixin meglumine helped to maintain acceptable cardiovascular function and tissue perfusion during endotoxemia. Flunixin meglumine given to healthy ponies had no effect on cardiovascular function.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
20.
Six insulin-sensitive and 6 insulin-insensitive mares were used in a replicated 3 by 3 Latin square design to determine the pituitary hormonal responses (compared with vehicle) to sulpiride and thyrotropin-releasing hormone (TRH), 2 compounds commonly used to diagnose pituitary pars intermedia dysfunction (PPID) in horses. Mares were classified as insulin sensitive or insensitive by their previous glucose responses to direct injection of human recombinant insulin. Treatment days were February 25, 2012, and March 10 and 24, 2012. Treatments were sulpiride (racemic mixture, 0.01 mg/kg BW), TRH (0.002 mg/kg BW), and vehicle (saline, 0.01 mL/kg BW) administered intravenously. Blood samples were collected via jugular catheters at −10, 0, 5, 10, 20, 30, 45, 60, 90, and 120 min relative to treatment injection. Plasma ACTH concentrations were variable and were not affected by treatment or insulin sensitivity category. Plasma melanocyte-stimulating hormone (MSH) concentrations responded (P < 0.01) to both sulpiride and TRH injection and were greater (P < 0.05) in insulin-insensitive mares than in sensitive mares. Plasma prolactin concentrations responded (P < 0.01) to both sulpiride and TRH injection, and the response was greater (P < 0.05) for sulpiride; no effect of insulin sensitivity was observed. Plasma thyroid-stimulating hormone (TSH) concentrations responded (P < 0.01) to TRH injection only and were higher (P < 0.05) in insulin-sensitive mares in almost all time periods. Plasma LH and FSH concentrations varied with time (P < 0.05), particularly in the first week of the experiment, but were not affected by treatment or insulin sensitivity category. Plasma GH concentrations were affected (P < 0.05) only by day of treatment. The greater MSH responses to sulpiride and TRH in insulin-insensitive mares were similar to, but not as exaggerated as, those observed by others for PPID horses. In addition, the reduced TSH concentrations in insulin-insensitive mares are consistent with our previous observation of elevated plasma triiodothyronine concentrations in hyperleptinemic horses (later shown to be insulin insensitive as well). 相似文献