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1.
Viruses ; 13(2)2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33535675

RESUMEN

Hepatitis E virus (HEV), a major cause of viral hepatitis worldwide, is considered an emerging foodborne zoonosis in Europe. Pigs (Sus scrofa domestica) and wild boars (S. scrofa) are recognized as important HEV reservoirs. Additionally, HEV infection and exposure have been described in cervids. In Norway, HEV has been identified in pigs and humans; however, little is known regarding its presence in wild ungulates in the country. We used a species-independent double-antigen sandwich ELISA to detect antibodies against HEV in the sera of 715 wild ungulates from Norway, including 164 moose (Alces alces), 186 wild Eurasian tundra reindeer (Rangifer tarandus tarandus), 177 red deer (Cervus elaphus), 86 European roe deer (Capreolus capreolus), and 102 muskoxen (Ovibos moschatus). The overall seroprevalence was 12.3% (88/715). Wild reindeer had the highest seropositivity (23.1%, 43/186), followed by moose (19.5%, 32/164), muskoxen (5.9%, 6/102), and red deer (4%, 7/177). All roe deer were negative. According to our results, HEV is circulating in wild ungulates in Norway. The high seroprevalence observed in wild reindeer and moose indicates that these species may be potential reservoirs of HEV. To the authors' knowledge, this is the first report of HEV exposure in reindeer from Europe and in muskoxen worldwide.


Asunto(s)
Animales Salvajes/sangre , Anticuerpos Antivirales/sangre , Virus de la Hepatitis E/inmunología , Hepatitis E/veterinaria , Rumiantes/sangre , Animales , Animales Salvajes/virología , Ciervos/sangre , Ciervos/virología , Hepatitis E/sangre , Hepatitis E/epidemiología , Virus de la Hepatitis E/clasificación , Virus de la Hepatitis E/genética , Noruega/epidemiología , Reno/sangre , Reno/virología , Rumiantes/virología , Estudios Seroepidemiológicos , Sus scrofa/sangre , Sus scrofa/virología , Porcinos , Enfermedades de los Porcinos/sangre
2.
J Wildl Dis ; 55(3): 544-562, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30605390

RESUMEN

Boreal woodland caribou (Rangifer tarandus caribou) are listed as threatened across Canada, and a basic understanding of their health status is lacking. From December 2012 to April 2013, we investigated multiple health indices for adult female boreal caribou (n=163) captured from seven herds in NE British Columbia, Canada. Health indices included physical characteristics, physiologic and trace mineral status, exposure to or infection with selected pathogens, and measures of chronic stress and inflammation, including serum amyloid A, haptoglobin, and hair cortisol concentration. Key findings were exposure to the bacterium Erysipelothrix rhusiopathiae in 14% of individuals, mild to severe hair loss associated with winter tick (Dermacentor albipictus) infestations in 76% of caribou from December to early February and 81% from late February to early April, and evidence of trace mineral deficiencies with 99% and 34% of individuals deficient in copper and selenium, respectively. Seroprevalence for exposure to selected pathogens was: alphaherpesvirus (63%), pestivirus (1%), Besnoitia spp. (60%), and Neospora caninum (2%). All animals were seronegative to Brucella spp. and Toxoplasma gondii. Mycobacterium avium ssp. paratuberculosis was not detected in any fecal samples. Parasite eggs or larvae, including Parelaphostrongylus andersoni (36%), Skrjabinema spp. (1%), Strongyle-type eggs (11%), Moniezia-type eggs (8%), and nematodirines (3%), were detected on fecal examination, but at low intensity. Blood biochemistry values and hair cortisol concentrations were within ranges previously reported in Rangifer tarandus sspp. Some significant differences among herds were noted, including antler morphology, exposure to Besnoitia spp., and concentrations of serum amyloid A, copper, cobalt, manganese, and iron.


Asunto(s)
Infecciones Bacterianas/veterinaria , Enfermedades Parasitarias en Animales/parasitología , Reno/sangre , Virosis/veterinaria , Envejecimiento , Animales , Cuernos de Venado , Infecciones Bacterianas/sangre , Infecciones Bacterianas/epidemiología , Colombia Británica/epidemiología , Femenino , Masculino , Enfermedades Parasitarias en Animales/sangre , Enfermedades Parasitarias en Animales/epidemiología , Estudios Seroepidemiológicos , Oligoelementos/sangre , Virosis/sangre , Virosis/epidemiología
3.
Comp Biochem Physiol B Biochem Mol Biol ; 149(4): 613-21, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18282730

RESUMEN

We examined the effects of prolonged undernutrition on plasma leptin and insulin levels and some serum protein metabolites in reindeer (Rangifer tarandus tarandus L.) during winter and spring. The reindeer (male <1 year) were fed their preferred winter feed, low-protein lichen ad libitum for 5 weeks, followed by 40% restriction of energy for 8 weeks and refeeding with high-protein pellets for 6 weeks. The control group received high-protein reindeer pellets ad libitum throughout the experiment. Plasma leptin decreased by 46% and insulin by 54% in the lichen group already during the ad libitum period between January and February, with parallel decreases in body weight, serum total proteins, albumin and urea. Leptin remained low during most of the energy restriction period in March and April, but increased at the end of April while body weight decreased. During the refeeding period in May and June, the body weight and insulin of the lichen group increased in parallel with total proteins and urea, but leptin remained unchanged. Similar significant reductions in plasma leptin (40%) as in the lichen group also took place in the control group fed high-protein pellets ad libitum in January and February, although their feed intake, serum total proteins and body weight remained unchanged. The results show that leptin decreases in reindeer during mid-winter, independent of food or protein intake, and suggest that the decrease may be cued by seasonal factors such as the short photoperiod.


Asunto(s)
Insulina/sangre , Leptina/sangre , Desnutrición/sangre , Reno/sangre , Estaciones del Año , Animales , Regiones Árticas , Glucemia/análisis , Peso Corporal , Creatinina/sangre , Fotoperiodo , Reno/metabolismo , Albúmina Sérica/análisis , Factores de Tiempo , Urea/sangre
4.
Comp Immunol Microbiol Infect Dis ; 29(2-3): 79-88, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16551478

RESUMEN

Age-related changes in serum concentrations of two acute phase proteins (APPs), haptoglobin (Hp) and serum amyloid-A (SAA) were investigated in newborn reindeer calves. Repeated blood samples were obtained from 51 reindeer calves at ages 0-32 days (2-4 samples from each calf). An increase of SAA concentrations was observed during the first 2 weeks of life. However, by the end of the observation period, SAA concentrations had decreased to levels below those of the first week. Serum Hp concentrations increased throughout the observation period. SAA concentrations in the second week had a negative association with weight gain during the entire study period (4 months). These time-related changes in APP concentrations suggest that these proteins have a role in the defence and adaptation mechanisms of newborn reindeer calves. Possible reasons for these changes include the presence of APP mediators in the colostrum, exposure to environmental pathogens after birth and age-related changes in hepatic synthesis of APP.


Asunto(s)
Haptoglobinas/metabolismo , Reno/sangre , Reno/crecimiento & desarrollo , Proteína Amiloide A Sérica/metabolismo , Aumento de Peso/fisiología , Factores de Edad , Animales , Animales Recién Nacidos , Femenino , Masculino
5.
Vet Immunol Immunopathol ; 111(3-4): 263-77, 2006 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-16584788

RESUMEN

To evaluate antigen-specific proliferative and activation-associated responses from Mycobacterium bovis-infected reindeer, blood mononuclear cells from M. bovis- (n = 10) and non-infected reindeer (n = 4) were stimulated with a recombinant early secretory antigenic target-6 and culture filtrate protein-10 fusion protein (rESAT6:CFP10), M. bovis purified protein derivative, pokeweed mitogen, or medium alone and evaluated by flow cytometry using dye tracker analysis and cell surface marker staining. gammadelta TCR+ and CD8+ cells, but not CD4+ cells, from M. bovis-infected reindeer proliferated in response to specific antigen stimulation. Expression (i.e., mean fluorescence intensity) of CD44 was increased and CD62L decreased on proliferative as compared to non-proliferative fractions in antigen- and mitogen-stimulated cultures. In response rESAT6:CFP10 stimulation, MHC II fluorescence intensity was increased on CD4+, gammadelta TCR+, CD172a+, and IgM+ cells from infected reindeer as compared to that of non-stimulated cells from the same reindeer. Recombinant ESAT6:CFP10 stimulation also induced expansion of a CD172a+, MHC II+ population within mononuclear cell cultures from M. bovis-infected reindeer. Despite a moderate challenge dose and extended duration of incubation, experimental infection of reindeer was generally limited to lymph nodes draining the inoculation site, suggestive of host resistance to progressive disease. Present in vitro findings, therefore, may be predictive of host responses by reindeer that limit progression to disseminated disease.


Asunto(s)
Leucocitos Mononucleares/inmunología , Mycobacterium bovis/inmunología , Proteínas Recombinantes de Fusión/inmunología , Reno/microbiología , Tuberculosis/veterinaria , Animales , Proliferación Celular , Epítopos , Citometría de Flujo , Antígenos de Histocompatibilidad Clase II/sangre , Receptores de Hialuranos/sangre , Selectina L/sangre , Leucocitos Mononucleares/citología , Subgrupos Linfocitarios/citología , Subgrupos Linfocitarios/inmunología , Masculino , Compuestos Orgánicos/química , Mitógenos de Phytolacca americana/inmunología , Reno/sangre , Reno/inmunología , Tuberculina/inmunología , Tuberculosis/inmunología , Tuberculosis/microbiología
6.
Can J Vet Res ; 70(2): 151-4, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16639949

RESUMEN

This study was designed to develop reliable methods for quantification of cortisol and cortisol immunoreactive metabolites (C-CIM) and immunoglobulin A (IgA) in reindeer serum, saliva, urine, and feces as tools for the objective noninvasive assessment of well-being and immunocompetence in reindeer. Although C-CIM was readily quantifiable by radioimmunoassay in serum, urine, and feces, the levels in saliva samples were low, rendering quantification unreliable. Whereas IgA concentrations were high in feces samples, they were much lower, albeit quantifiable, in serum and urine; the levels in saliva samples were too low for quantification with the use of an enzyme-linked immunosorbent assay that we developed. Further studies are in progress to validate the usefulness of fecal levels of C-CIM and IgA in the assessment of welfare in reindeer.


Asunto(s)
Hidrocortisona/metabolismo , Inmunoglobulina A/metabolismo , Reno , Estrés Psicológico/diagnóstico , Enfermedad Aguda , Animales , Biomarcadores/análisis , Biomarcadores/sangre , Biomarcadores/metabolismo , Heces/química , Femenino , Hidrocortisona/sangre , Inmunoglobulina A/sangre , Masculino , Reno/sangre , Saliva/química , Estrés Psicológico/metabolismo , Orina/química
7.
J Wildl Dis ; 42(2): 249-58, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16870847

RESUMEN

During an 18-mo period (May 2002-November 2003), 10 animals in a herd of 19 reindeer (Rangifer tarandus) at the National Animal Disease Center (NADC) experienced episodes of anemia. Affected animals had histories of weight loss, unthriftiness, occasionally edema of dependent parts and moderate anemia characterized by microcytosis or macrocytosis, hypochromasia, schistocytosis, keratocytosis, acanthocytosis, and dacryocytosis. Numerous basophilic punctate to ring-shaped bodies, measuring less than 1.0 microm, were found on the surface of red blood cells and were often observed encircling the outer margins of the cells. Based on cytologic findings, DNA preparations from selected affected animals in the NADC herd and one animal from a private herd experiencing similar episodes of anemia were assayed by polymerase chain reaction (PCR) for the presence of hemotropic bacteria using primers targeting the 16S rRNA genes of Mycoplasma (Eperythrozoon) suis, Mycoplasma (Haemobartonella) haemofelis, Anaplasma marginale, Anaplasma spp., and Ehrlichia spp. Amplification products were detected from four of the affected animals using primers specific for the 16S rRNA gene of M. haemofelis and Mycoplasma haemocanis. Product from one of the animals was sequenced and internal primers were designed from the resulting sequence to perform a nested PCR assay. Samples from 10 reindeer were positive using the nested PCR reaction and products from seven animals were sequenced; BLAST searches and phylogenetic analysis were performed on the resulting sequences. Sequence data from six animals revealed homology to an organism most closely related to Mycoplasma ovis, Mycoplasma wenyonii, and Mycoplasma haemolamae; sequence from a single animal was most closely related to M. haemofelis and M. haemocanis. This represents the first identification of a haemomycoplasma species in reindeer. Although several animals were also infected with abomasal nematodes, the presence of this newly described haemomycoplasma may have contributed to the anemic syndrome.


Asunto(s)
Anaplasma/aislamiento & purificación , Anemia/veterinaria , Ehrlichia/aislamiento & purificación , Mycoplasma/aislamiento & purificación , Reno/microbiología , Anaplasma/clasificación , Anaplasma/genética , Anemia/diagnóstico , Anemia/microbiología , Animales , Animales Salvajes , Secuencia de Bases , Ehrlichia/clasificación , Ehrlichia/genética , Femenino , Amplificación de Genes , Masculino , Mycoplasma/clasificación , Mycoplasma/genética , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico 16S/análisis , Reno/sangre
8.
Biochim Biophys Acta ; 1076(2): 221-4, 1991 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-1998722

RESUMEN

The primary structures of alpha- and beta-chains of hemoglobin from reindeer (Rangifer tarandus tarandus) were determined. Comparison of the reindeer hemoglobin sequence with those of human and bovine hemoglobins showed 50 and 29 substitutions per alpha beta dimer, respectively. The influence of replacements on the modulation of hemoglobin oxygen affinity by heterothopic ligands and temperature, as well as their importance on the structure-function relationships in hemoglobin are discussed.


Asunto(s)
Hemoglobinas/metabolismo , Reno/sangre , Secuencia de Aminoácidos , Animales , Bovinos/sangre , Ciervos/sangre , Hemoglobinas/genética , Hemoglobinas/aislamiento & purificación , Humanos , Datos de Secuencia Molecular , Oxihemoglobinas/metabolismo , Homología de Secuencia de Ácido Nucleico
9.
Biochem J ; 380(Pt 3): 889-96, 2004 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-14979874

RESUMEN

Haemoglobins from mammals of sub-Arctic and Arctic species, as well as fetal human Hb, are all characterized by a significantly lower Delta H of oxygenation compared with the majority of mammalian haemoglobins from temperate species (exceptions are represented by some cold-resistant species, such as cow, horse and pig). This has been interpreted as an adaptive mechanism of great importance from a physiological point of view. To date, the molecular basis of this thermodynamic characteristic is still not known. In the present study, we show that binding of extra chloride (with respect to adult human Hb) ions to Hb would significantly contribute to lowering the overall heat of oxygenation, thus providing a molecular basis for the low effect of temperature on the oxygenation-deoxygenation cycle. To this aim, the oxygen binding properties of bovine Hb, bear (Ursus arctos) Hb and horse Hb, which are representative of this series of haemoglobins, have been studied with special regard to the effect of heterotropic ligands, such as organic phosphates (namely 2,3-diphosphoglycerate) and chloride. Functional results are consistent with a mechanism for ligand binding that involves an additional binding site for chloride ion. Analysis of computational chemistry results, obtained by the GRID program, further confirm the hypothesis that the reason for the lower Delta H of oxygenation is mainly due to an increase in the number of the oxygen-linked chloride-binding sites.


Asunto(s)
Cloruros/metabolismo , Cloruros/fisiología , Hemoglobinas/química , Hemoglobinas/fisiología , 2,3-Difosfoglicerato/metabolismo , Adulto , Aminoácidos/metabolismo , Aminoácidos/fisiología , Animales , Sitios de Unión/fisiología , Bovinos/sangre , Biología Computacional/métodos , Simulación por Computador , Eritrocitos/química , Hemoglobina Fetal/química , Hemoglobina Fetal/fisiología , Feto/irrigación sanguínea , Caballos/sangre , Humanos , Oxígeno/metabolismo , Reno/sangre , Especificidad de la Especie , Porcinos/sangre , Termodinámica , Ursidae/sangre
10.
Theriogenology ; 63(6): 1775-88, 2005 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-15763117

RESUMEN

The endocrinology was studied throughout pregnancy in reindeer (Rangifer tarandus tarandus) located in Oulu, Finland (65 degrees N, 25 degrees E) with 13 captive, semi domestic adult females. Blood samples were analyzed for plasma progesterone (P4), estradiol (E2) and estrone sulphate (E1SO4), 15-ketodihydro-PGF2alpha (PG-metabolite) and pregnancy associated glycoproteins (PAG). The mean plasma P4 concentration peaked twice during gestation: at around 24 and three weeks prior to calving. In pregnant females the plasma PAG concentration increased over basal concentrations 21-30 days after the estimated day of conception and peaked at the time of calving. The concentrations of E2 and E1SO4 remained low until 60 days before calving when a rapid increase was found for both hormones. The mean plasma concentration of PG-metabolite increased throughout pregnancy to a maximum at parturition. The estimated mean (range) gestation length was 216 (212-220) days. Judged from measures on reproductive organs collected from 86 free-ranging, semi-domestic female reindeer of unknown age presented for slaughter at Roros, Norway (63 degrees N, 11 degrees E) in the second week of December 1999, it was concluded that the breeding season lasted from early September until the end of November. The results also showed that plasma PAG concentration could provide a tool for detection of pregnancy in reindeer.


Asunto(s)
Estrona/análogos & derivados , Hormonas/sangre , Pruebas de Embarazo/veterinaria , Preñez/sangre , Reno/sangre , Animales , Animales de Zoológico , Estradiol/sangre , Estrona/sangre , Femenino , Finlandia , Edad Gestacional , Glicoproteínas/sangre , Embarazo , Proteínas Gestacionales/sangre , Progesterona/sangre , Prostaglandinas/sangre
11.
Endocrinology ; 130(3): 1645-52, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1537312

RESUMEN

Daily patterns of pineal function were studied in different seasons in 10 adult semidomesticated female reindeer and 5 prepubertal calves living in a natural arctic environment at latitude 69 degrees 10'N. Serum samples for melatonin RIA were collected every 4 h for 24 h in October (10 h of light, 14 h of darkness and 8 h of light, 16 h of darkness), December (24 h of darkness), March (13 h of light, 11 h of darkness), and June (24 h of light). A significant daily variation in serum melatonin levels was observed in the adult reindeer, with peak values (20-50 ng/liter) occurring during the night in autumn, winter, and spring, but not summer. The daytime values at 13 h (5-10 ng/liter) were constant throughout the year. Total daily amounts of melatonin, the duration of peak levels, and maximal concentrations were significantly lower in spring and summer than before the rut in autumn. The exposure of adult animals to artificial darkness from bright sunlight on August 1 and September 21 resulted in an immediate increase in serum melatonin concentrations. The 2-week-old calves had detectable serum melatonin levels, but no daily rhythm in the spring, whereas a rhythm was detectable by the first autumn, only to disappear unexpectedly during the first winter and return in the spring. At the age of 16 months, the calves had serum melatonin concentrations similar to those in the adults. Our present results show that the continuous illumination experienced during the summer abolished the normal daily melatonin rhythm. This does not seem to be related to organic changes in the pineal gland, since exposure to darkness during the summer increased melatonin levels. The highest melatonin secretion occurred in the autumn and was evidently associated with the rut. Similarly, the daily melatonin rhythm of an adult type observed in the calves at the age of 16 months may be related to the observation that most calves were in rut. Thus, a high rhythmical melatonin secretion appears to relate to puberty and the initiation of heat in female reindeer.


Asunto(s)
Animales Recién Nacidos/sangre , Ritmo Circadiano/fisiología , Melatonina/sangre , Reno/sangre , Estaciones del Año , Animales , Femenino , Luz , Glándula Pineal/metabolismo , Glándula Pineal/fisiología , Radioinmunoensayo , Reno/fisiología
12.
Endocrinology ; 129(2): 679-82, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1855465

RESUMEN

Insulin-like growth factor-I (IGF-I) concentrations were measured in the plasma of reindeer calves exposed to a manipulated photoperiod, indoors, of either 16 h light followed by 8 h dark each day (16L:8D) (n = 3) or 8L:16D (n = 3) from about the autumnal to the vernal equinox, to determine whether the seasonal growth spurt normally seen in spring is associated with a photoperiod-induced rise in IGF-I. A high quality concentrate diet was available ad libitum, and individual food intake was recorded daily. The animals were weighed, bled, and the diameters of their testes were measured every 2 weeks. Plasma samples were assayed for IGF-I by RIA. Six to 8 weeks after the start of the study those calves exposed to 16L:8D showed a significant increase in plasma IGF-I concentration, which was maintained until the close 24 weeks after the start. In contrast, IGF-I plasma concentrations in those calves exposed to a day length of 8L:16D did not significantly alter during the study. The elevated IGF-I in the 16L:8D group was associated with rapid weight gain, higher food intake, and decreased testes size compared with the 8L:16D group. We have shown that the seasonal growth spurt is preceded by an elevation in plasma IGF-I concentration. Further, this elevation in IGF-I is day length dependent. This is the first account of any growth factor secretion being regulated by photoperiod.


Asunto(s)
Factor I del Crecimiento Similar a la Insulina/metabolismo , Luz , Periodicidad , Reno/sangre , Animales , Ingestión de Alimentos , Masculino , Reno/anatomía & histología , Estaciones del Año , Testículo/anatomía & histología , Aumento de Peso
13.
J Endocrinol ; 141(3): 527-33, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8071651

RESUMEN

The reindeer in its natural habitat is subject to great annual variations in ambient temperature, illumination and nutrition. To ascertain the effect of these environmental factors on thyroid function, serum thyroid-stimulating hormone (TSH), thyroxine (T4), tri-iodothyronine (T3) and reverse T3 (rT3) concentrations were measured four times a year (2 June, 8 October, 21 November, and 24 February) in 14 animals housed outdoors at latitude 69 degrees 10'N. They all showed statistically significant (P < 0.05) seasonal changes. Serum TSH and T4 were highest in February (623 +/- 30 ng/ml and 287 +/- 19 nmol/l respectively). TSH was lowest in October (318 +/- 47 ng/ml) and T4 in November (199 +/- 19 nmol/l). The T3 concentration was highest in November (3.0 +/- 0.3 nmol/l) and lowest in June (1.8 +/- 0.2 nmol/l). In contrast, rT3 was highest in June (3.6 +/- 1.2 nmol/l) and lowest in November (1.9 +/- 0.6 nmol/l). Thus, there was an inverse relationship between T3 and rT3 (linear regression r = -0.406, P < 0.01). TSH, T4, T3 and rT3 responses to exogenous thyrotrophin-releasing hormone (synthetic TRH; 500 micrograms i.m.) were determined in ten animals. The magnitude of their response to TRH was significantly (P < 0.05) dependent on the time of year. When compared with the control level all the parameters rose significantly (P < 0.05). The greatest rise in serum TSH occurred in October (219 +/- 151%) and the smallest in February (66 +/- 53%).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Ambiente , Reno/sangre , Estaciones del Año , Hormonas Tiroideas/sangre , Hormona Liberadora de Tirotropina/farmacología , Tirotropina/sangre , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Femenino , Luz , Temperatura , Glándula Tiroides/efectos de los fármacos , Tiroxina/sangre , Triyodotironina/sangre , Triyodotironina Inversa/sangre
14.
Biophys Chem ; 37(1-3): 281-6, 1990 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-2285789

RESUMEN

The most surprising characteristic of reindeer hemoglobin (Hb) concerns its response to changes in temperature. Thus, the shape of the oxygen-binding curve is strongly temperature dependent due to the difference in the enthalpy of oxygenation between the T and R state of the molecule. In fact, delta H of oxygen binding to the T state is strongly exothermic whereas that of the R state is very close to zero or possibly positive after correction for the heat of oxygen solubilization. Moreover, the allosteric transition T0----R0 has been found to display a negative delta H and a contemporaneous decrease in entropy, a behavior which is precisely the opposite of what has been reported for other hemoglobins. As a whole, reindeer Hb represents a beautiful example of the significance that comparative studies may have in assessing the general validity of the main properties of the hemoglobin molecule.


Asunto(s)
Hemoglobinas/metabolismo , Oxihemoglobinas/metabolismo , Reno/sangre , 2,3-Difosfoglicerato , Animales , Regiones Árticas , Ácidos Difosfoglicéricos/metabolismo , Hemoglobina A/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Cinética , Matemática , Modelos Teóricos , Conformación Proteica , Termodinámica
15.
Artículo en Inglés | MEDLINE | ID: mdl-12381382

RESUMEN

We investigated whether secretion of insulin occurred in the absence of feeding in a ruminant. Serum insulin, glucose and lactate concentrations were measured in three adult non-pregnant reindeer at hourly intervals during an 18-h fast (17:30-11:30 h) in October. Mean serum insulin concentration was 39+/-3 micro/ml (range 2-100). The insulin profile of two animals was characterized by a nocturnal rise and an early morning trough, followed by a mid-morning rise. Within the larger peaks, short-term oscillations occurred at 2-3-h intervals. Serum glucose concentrations significantly increased during the fast and exceeded feeding values by 31-45% at 18 h post feeding. Serum lactate concentrations declined significantly in all three animals. Residuals for serum glucose concentrations were significantly negatively correlated to residuals of serum lactate in two animals, but not the third. Serum glucose and lactate concentrations were not related to serum insulin. In conclusion, insulin secretion in reindeer shows a 2-3-h periodicity in the absence of feeding. The periodicity is of similar duration as the inter-meal interval for pen-fed reindeer during winter (2.5 h). Although not necessarily causal, the results are consistent with a hypothesized role for insulin in meal initiation.


Asunto(s)
Glucemia/análisis , Ayuno/sangre , Insulina/sangre , Ácido Láctico/sangre , Animales , Ritmo Circadiano , Femenino , Periodicidad , Reno/sangre , Reno/metabolismo , Factores de Tiempo
16.
Artículo en Inglés | MEDLINE | ID: mdl-10327601

RESUMEN

Annual cycle of type I collagen formation and degradation and antler growth was studied in six adult female reindeer, Rangifer tarandus tarandus. Blood samples were collected twice a week during 1 year. Antler length was measured weekly during the antler growth period. An assay for human PICP, the carboxyterminal propeptide of type I procollagen, was used as an indicator of type I collagen formation and an assay for bovine ICTP, the carboxyterminal telopeptide of type I collagen, as an indicator of type I collagen degradation. PICP was clearly increased during the antler growth period. Also ICTP was slightly elevated during antler growth, but the highest values were found in autumn and winter. Our statistical analysis revealed that changes in lagged values (from 3 to 6 weeks) of PICP could be linked to the subsequent changes in the growth rate of the antler, although the highest values of PICP were found during the final third of antler growth. ICTP had significant predictive power as well, but the connection with the growth rate seemed more immediate than that of PICP. In conclusion, antler collagen synthesis can be predicted by PICP, but also ICTP was related to the antler growth.


Asunto(s)
Cuernos de Venado/fisiología , Colágeno/sangre , Fragmentos de Péptidos/sangre , Péptidos/sangre , Procolágeno/sangre , Reno/fisiología , Animales , Bovinos , Colágeno Tipo I , Femenino , Humanos , Modelos Lineales , Reno/sangre , Reno/crecimiento & desarrollo , Estaciones del Año , Factores de Tiempo
17.
Comp Biochem Physiol B Biochem Mol Biol ; 116(2): 269-77, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9159890

RESUMEN

Seasonal levels of LH, FSH, testosterone (T), estradiol, progesterone (P), and prolactin (PRL) were determined in the plasma of five adult bulls, and five barren and four pregnant cows of Alaskan reindeer (Rangifer tarandus), which were sampled every 3 weeks for 54 weeks. The male reproductive axis was sequentially activated; LH peaked in May-June (2 ng/ml), FSH in June (51 ng/ml), and T in September (11.8 ng/ml). LH levels in females reached a maximum in both groups at the end of August (the beginning of the rut). Seasonal variation in FSH was minimal in pregnant cows, but exhibited one elevation (41 ng/ml) in barren ones in November. T levels in cows remained at barely detectable levels. The decrease of T values observed in both groups in December and March was not significant. PRL peaked in May in cows (135 ng/ml pregnant, 140 ng/ml non-pregnant) and in June in bulls (92 ng/ml). Estradiol was highest in bulls in the rut (August), in non-pregnant cows in January and in pregnant cows in April, shortly before parturition. P levels in the pregnant cows rose from September and peaked (9 ng/ml) shortly before parturition in April. In the non-pregnant females P values increased and decreased several times before peaking (5 ng/ml) in March. In the males, the variation of T and estradiol levels correlated relatively well with the antler cycle but in the females the variation of neither estradiol, progesterone nor T appeared to be related to mineralization or casting of antlers.


Asunto(s)
Cuernos de Venado/crecimiento & desarrollo , Hormonas Esteroides Gonadales/sangre , Reno/sangre , Reno/crecimiento & desarrollo , Animales , Estradiol/sangre , Femenino , Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Masculino , Embarazo , Progesterona/sangre , Prolactina/sangre , Reno/fisiología , Reproducción , Estaciones del Año , Testosterona/sangre
18.
Artículo en Inglés | MEDLINE | ID: mdl-9827045

RESUMEN

Seasonal levels of cortisol, growth hormone (GH), insulin like growth factor 1 (IGF-1), glucose, triiodothyronine (T3), free T3, thyroxine and free fatty acids (FFA) were measured every 3 weeks for 54 weeks in the plasma of five adult bulls, and four barren and five pregnant Alaskan reindeer (Rangifer tarandus) cows. Three consecutive samples were taken from each animal. Cortisol levels exhibited wide seasonal variation (9-45 ng/ml) [corrected] without any peak or difference in levels among groups. Rising levels were detected between the 3 consequent samples. Peak GH levels, detected during January and February, were higher in the non-pregnant group (54 ng/ml) than the pregnant (26 ng ml-1) and the male (27 ng ml-1) groups. Low GH levels (2-10 ng ml-1) were recorded between May and September. IGF-1 reached peak levels (715 ng ml-1) in males in August, in non-pregnant females in September (677 ng ml-1), and in the pregnant females in October (505 ng ml-1). Seasonal minima (404 in males, 172 and 93 in pregnant and non-pregnant groups) were detected in February. Glucose was fairly stable throughout the year (100-200 mg/100 ml). A rising levels were found between the three consecutive samples. Triiodothyronine (T3) (2.16-2.30 ng ml-1) peaked in all three groups during the spring and early summer, and minimal levels (0.61-0.97 ng ml-1) were detected from October to January. Conversely, thyroxine or free T3 did not exhibit seasonal variation. FFA fluctuated widely (97-1076 nmol l-1) throughout the year. Only in pregnant females were concentrations more stable (150-460 nmol l-1). Perhaps, because of ad libitum supply of food in captive reindeer, only T3 and GH exhibited pronounced seasonal fluctuations which could be related to the metabolic changes expected during the annual cycle.


Asunto(s)
Hormona del Crecimiento/sangre , Hidrocortisona/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Reno/sangre , Tiroxina/sangre , Triyodotironina/sangre , Alaska , Animales , Glucemia/análisis , Ácidos Grasos no Esterificados/sangre , Femenino , Análisis de los Mínimos Cuadrados , Masculino , Embarazo , Radioinmunoensayo , Estaciones del Año , Factores Sexuales
19.
Domest Anim Endocrinol ; 26(2): 87-98, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-14757182

RESUMEN

The effects of manual blood sampling and remote blood sampling using automatic blood sampling equipment (ABSE) on plasma cortisol and catecholamine concentrations were studied on eight adult female reindeer (Rangifer tarandus tarandus). Contemporary body temperatures and heart rates were also recorded to determine their utility as other possible stress indicators. The animals were blood sampled once every hour with ABSE on 9-10 May and then by manual blood sampling on 13-14 May. Animals were also fitted with equipment to record heart rate and body temperature. Heart rate and body temperature were also recorded continuously without blood sampling on 17-18 May in undisturbed control conditions. Plasma cortisol concentrations were five-to-six fold greater during manual blood sampling compared to sampling with ABSE (F(1,3) = 13.34, P < 0.05). Plasma noradrenaline concentrations were significantly higher (F(1,3) = 22.98, P < 0.05) during manual blood sampling compared to sampling with ABSE, whereas plasma adrenaline concentrations did not differ. Heart rate was higher during manual blood sampling compared to control values. Body temperature was significantly higher during manual sampling compared to values recorded without blood sampling (F(1,4)= 31.65, P < 0.01). In conclusion, plasma cortisol concentration provides an excellent indicator of handling stress in reindeer. The use of ABSE for blood sampling enables measurements of plasma cortisol levels close to basal concentrations that may be used for reference values in studies where indicators of physiological stress are required.


Asunto(s)
Recolección de Muestras de Sangre/psicología , Recolección de Muestras de Sangre/veterinaria , Reno/sangre , Estrés Fisiológico/sangre , Estrés Fisiológico/veterinaria , Animales , Temperatura Corporal/fisiología , Epinefrina/sangre , Femenino , Manejo Psicológico , Frecuencia Cardíaca/fisiología , Hidrocortisona/sangre , Norepinefrina/sangre , Reno/psicología
20.
Anim Reprod Sci ; 72(1-2): 27-35, 2002 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-12106963

RESUMEN

Reindeer are seasonally polyestrus, short day breeders, with estrous cycles of approximately 20 days in length. The objective of this study was to investigate the effects of reindeer bull exposure on the onset of the reindeer cow breeding season and to investigate whether cows with calving experience responded differently than cows with no previous reproductive experience. During year 1, blood samples were collected weekly beginning 14 July and continuing until 15 September (n = 8) or 30 September (n = 8) in order to determine the onset of the breeding season, based on ovarian function, with no bull present. Plasma was stored frozen for later assay of progesterone (P(4)) following the conclusion of sample collection. Eight randomly selected cows were allowed to breed with a bull during year 1. The mean onset of ovarian activity in the first year was 15 September (range: 8-29 September). The bull was removed from cows more than 2 months prior to the start of the experimental period during year 2 and housed at a separate facility approximately 2 km distant. Blood samples were collected during year 2 from 14 cows 3x weekly beginning on 11 August (day 1) and continuing until 29 September (day 50) and plasma was stored frozen for later assay of P(4) following the conclusion of sample collection. On day 6, cows were divided into two groups such that group 1 (early bull exposure; EBE), consisted of four cows that had calved the previous spring and four cows that had no reproductive experience (n = 8). Group 2 (late bull exposure; LBE), consisted of three cows that had calved the previous spring and three cows that had no reproductive experience (n = 6). EBE experienced bull introduction on day 13, 23 days earlier than the average onset of ovarian activity during year 1. LBE experienced bull introduction on day 46, 10 days later than the average onset of ovarian activity during year 1. Progesterone concentrations were analyzed by ANOVA procedures for repeated measures. Bull presence was not requisite for the onset of ovarian activity during either year. Previous reproductive status had no effect on the onset of ovarian activity within EBE (P = 0.61) or within LBE (P = 0.92). Time of bull introduction had a significant effect on the onset of ovarian activity when EBE was compared to LBE (P<0.001). The first sustained increase in mean P(4) concentration above 1 ng/ml occurred on day 25 in EBE reindeer and day 41 in LBE reindeer. EBE reindeer initiated ovarian activity 12 days after bull introduction while LBE reindeer initiated ovarian activity 5 days before bull introduction. All cows penned with the bull conceived during both breeding seasons, demonstrated by production of live calves during the subsequent spring. Cows bred during year 1 all calved within a 9 day-period. During year 2, EBE displayed a more synchronous calving period compared to LBE (P<0.05). Results indicate that bull management affects the onset of the breeding season in reindeer cows, regardless of previous reproductive experience.


Asunto(s)
Estro/fisiología , Ovario/fisiología , Paridad/fisiología , Progesterona/sangre , Reno/fisiología , Animales , Cruzamiento , Femenino , Masculino , Embarazo , Reno/sangre , Estaciones del Año , Conducta Sexual Animal , Factores de Tiempo
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