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J Anim Sci ; 80(2): 494-501, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11881933


A study was conducted with 20 weaned barrows (14 d, 4.98 +/- .21 kg) to determine the effect of spray-dried plasma (SDP) on the pig's immune response to a lipopolysaccharide (LPS) challenge. After weaning, pigs were fed a diet containing 0 or 7% SDP for 7 d. On d 6 postweaning, all pigs were fitted with a jugular catheter. On d 7 postweaning, the pigs were given an i.p. injection of either saline or LPS (150 microg/kg BW) followed by a 3-h blood collection every 15 min. Following blood collection, all pigs were killed and tissue was collected for mRNA analysis. Additionally, the small intestine was collected for measurement of villus height, crypt depth, and villus height:crypt depth ratio (VCR) at three sites (25, 50, and 75% of the total length). Feeding SDP resulted in reduced (P < 0.05) mRNA expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA in the adrenal gland, spleen, hypothalamus, pituitary gland, and liver. Additionally, expression of IL-6 mRNA was reduced (P < 0.05) in the spleen and pituitary gland for pigs fed SDP. For pigs fed the diet with SDP, LPS administration did not affect (P > 0.10) cytokine mRNA expression, whereas LPS reduced expression of TNF-alpha mRNA in the spleen and IL-1beta mRNA in the adrenal gland, spleen, and thymus for pigs fed the diet without SDP. For pigs fed the diet with SDP, LPS caused serum TNF-alpha to increase 150-fold compared to a 60-fold increase for pigs fed the diet without SDP. Similarly, interferon-gamma (IFN-gamma) increased 110-fold for pigs fed the diet with SDP compared to a 16-fold increase for pigs fed the diet without SDP. For pigs fed the diet with SDP, LPS caused major villus atrophy, whereas for pigs fed the diet without SDP, LPS had no effect on intestinal morphology. These results demonstrate that the basal activation of the immune system appears to be less for pigs fed the diet with SDP compared to pigs fed the diet without SDP after weaning. Additionally, for pigs fed the diet with SDP, there appeared to be an overresponse of the immune system following LPS administration, which resulted in major damage to the mucosa of the gastrointestinal tract.

Intestino Delgado/efectos de los fármacos , Lipopolisacáridos/farmacología , Porcinos/inmunología , Glándulas Suprarrenales/efectos de los fármacos , Glándulas Suprarrenales/inmunología , Animales , Cateterismo/veterinaria , Hipotálamo/efectos de los fármacos , Hipotálamo/inmunología , Inyecciones Intraperitoneales/veterinaria , Interferón gamma/metabolismo , Interleucina-1/metabolismo , Intestino Delgado/patología , Lipopolisacáridos/inmunología , Hígado/efectos de los fármacos , Hígado/inmunología , Masculino , Hipófisis/efectos de los fármacos , Hipófisis/inmunología , ARN Mensajero/metabolismo , Distribución Aleatoria , Bazo/efectos de los fármacos , Bazo/inmunología , Timo/efectos de los fármacos , Timo/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Destete
Domest Anim Endocrinol ; 16(3): 145-8, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10343916


Early growth is an important determinant of gain and efficiency in growing pigs. A major limiting factor of piglet growth is feed intake. Orexins, newly discovered neuropeptides, may be important regulators of appetite. The orexin gene, which encodes orexin-A and -B, was recently identified in rodents and man. The objectives of this study were to clone the cDNA for porcine orexin, utilize the cDNA sequence information to produce synthetic hormone, and evaluate the effect of orexin administration on feed intake in weanling pigs. Oligonucleotide primers were designed for reverse transcription polymerase chain reaction production of porcine orexin cDNA. The polymerase-chain-reaction products were cloned, sequenced, and found to be 88.5% homologous to the human orexin sequence. Predicted translation of porcine orexin cDNA revealed orexin-A and -B amino acid sequences that were 100% and 96% homologous to the known human peptides, respectively. Porcine orexin-B was synthesized according to the predicted sequence. Twenty-six cross-bred piglets were utilized in three replicates (n = 8-10/replicate). Piglets were weaned between 2-3 wk of age. One week after weaning, equal numbers of animals in each replicate received intramuscular (i.m.) injections of orexin-B (3 mg/kg body weight) or vehicle (sterile water). Feed intake was monitored from -24 to 24 h relative to injection (time 0). The orexin-injected pigs ingested an additional meal at 12 h when compared with the control animals (P = 0.02). Cumulative feed intake was increased by orexin-B administration from 12 to 24 h postinjection (P < or = 0.05). Total feed intake at 24 h was improved by 18% in orexin-treated pigs (P = 0.05). The ability to stimulate appetite during critical periods of early growth, particularly following weaning, could result in significant improvements in swine-production efficiency.

Clonación Molecular , Ingestión de Alimentos/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular , Neuropéptidos/administración & dosificación , Neuropéptidos/genética , Precursores de Proteínas/genética , Porcinos/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Proteínas Portadoras/química , Proteínas Portadoras/genética , ADN Complementario/química , ADN Complementario/genética , Humanos , Inyecciones Intramusculares , Datos de Secuencia Molecular , Neuropéptidos/química , Orexinas , Homología de Secuencia , Destete
Domest Anim Endocrinol ; 14(5): 295-303, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9347250


The physiological regulation of food intake is a critical factor in both the rate at which an animal grows and its reproductive activity. Recently, progress has been made in elucidating a complex system in which insulin, leptin, and neuropeptide Y function to monitor an animal's energy balance and regulate feed intake and fertility. RNA was extracted from ovine hypothalamic, anterior pituitary, pancreas, and adipose tissue. Using the reverse transcription-polymerase chain reaction. cDNAs were cloned and sequenced for leptin (350 base pairs [bp], GenBank accession number U62123 and 441 bp, GenBank accession number U84247), NPY-Y1 receptor (350 bp, GenBank accession no. U62122) and NPY-Y2 receptor (440 bp, GenBank accession no. U83458). Probes generated from these clones were used to detect mRNA expression within tissues thought to be involved in the coregulation of feed intake and reproduction. Leptin was found to be expressed in sheep adipose tissue. The ovine NPY-Y1 receptor mRNA was detected within the arcuate nucleus and paraventricular nucleus of the hypothalamus, the dentate gyrus of the hippocampus and in pancreatic, anterior pituitary, and adipose tissues. Expression of ovine NPY-Y2 receptor mRNA was detected in the hippocampus and within pancreatic tissue. These observations provide evidence of potential mechanisms that exist for mediating communication between peripheral and central tissues within the insulin-leptin-NPY pathway.

Clonación Molecular , Expresión Génica , Proteínas/genética , Receptores de Neuropéptido Y/genética , Ovinos/genética , Tejido Adiposo/química , Animales , ADN Complementario/genética , Femenino , Hipotálamo/química , Leptina , Especificidad de Órganos , Páncreas/química , Adenohipófisis/química , ARN Mensajero/análisis
Domest Anim Endocrinol ; 14(2): 119-28, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9063654


Infertility associated with suboptimal nutrition is a major concern among livestock producers. Recently, much effort has been put into understanding the role of the protein leptin in regulating feed intake and reproduction. Leptin, produced by adipocytes, has receptors in the hypothalamus, but more precise locations of leptin receptor-expressing cell bodies have not been reported in a livestock species. The leptin receptor transcript has several splice variants in the mouse and human, but only the "long-form" product (OBRL) is capable of signal transduction. A partial ovine long-form leptin receptor cDNA was cloned and used to evaluate OBRL mRNA expression within hypothalamic, anterior pituitary, and adipose tissues of ovariectomized adult ewes. Expression was detected in reverse transcription-polymerase chain reaction products of all tissues examined. OBRL mRNA was detected by in situ hybridization in the ventromedial and arcuate nuclei of the hypothalamus. In ewes that had been feed restricted for 3 wk before tissue collection, the expression of OBRL mRNA in these areas was greater (P < 0.05) than that found in well-fed ewes. These findings provide evidence that the full-length leptin receptor is expressed in hypothalamic, anterior pituitary, and adipose tissue (the latter proffering an autoregulatory mechanisms for leptin) and that within the hypothalamus, this receptor form is differentially expressed in well-fed vs. feed-restricted animals.

Tejido Adiposo/metabolismo , Proteínas Portadoras/genética , Expresión Génica , Hipotálamo/metabolismo , Adenohipófisis/metabolismo , Receptores de Superficie Celular , Ovinos , Secuencia de Aminoácidos , Animales , Southern Blotting , Proteínas Portadoras/química , Clonación Molecular , Femenino , Privación de Alimentos , Humanos , Hibridación in Situ , Ratones , Datos de Secuencia Molecular , Ovariectomía , ARN Mensajero/metabolismo , Receptores de Leptina , Homología de Secuencia