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At least 685 records · Page 38Linked to original sources
PubMed1991

Fine structure of secondary granule inclusions in fowl heterophils after ruthenium tetroxide fixation.

Bone marrow from domestic fowls was initially fixed for electron microscopy in glutaraldehyde and post-fixed with either ruthenium tetroxide or osmium tetroxide. Inclusions with distinct outlines were revealed in the secondary granules of heterophil leucocytes after ruthenium tetroxide but not with osmium tetroxide fixation. In longitudinal orientation, these inclusions were rod-shaped and composed of microfilaments measuring 3.7 nm in diameter. In transverse section, the outline of some of these inclusions was hexagonal and therefore the inclusions may be crystalline in nature.

Animals↗
PubMed1992

Effects of age, sex and housing on the trabecular bone of laying strain domestic fowl.

To determine the effects of age, sex and housing on trabecular bone volume, samples were collected from groups of male and female domestic fowl housed in cages or floor pens from four to 60 weeks old. Between 25 and 60 weeks old, trabecular bone volume decreased by 25 per cent in sections of free thoracic vertebrae (T5) from female birds, the loss occurring at an earlier age in caged birds. Over the sample period, TBV in male caged birds diminished by 35 percent, but male floor birds showed no reduction in trabecular bone volume. At 60 weeks, trabecular bone volume was 30 per cent greater in male caged birds and 40 per cent greater in male floor birds than in the corresponding females. In reproductively active females, no trabecular osteoid was observed, indicating no new trabecular bone formation. However, trabecular osteoid was present in two birds aged 60 weeks which had regressed ovaries. Osteomalacia was not seen in any of the bone samples.

Aging↗
PubMed1995

Creatine kinase isoenzyme profiles in the plasma of the domestic fowl (Gallus domesticus): effects of acute heat stress.

Creatine kinase isoenzyme activities in extracts of plasma, skeletal muscle, heart and brain tissue of domestic fowls were separated by anion exchange chromatography and tissue specific distributions of the isoenzyme designated MM-CK, BB-CK1 and BB-CK2 were demonstrated. The muscle isoenzyme (MM-CK) was the predominant form in plasma (99 per cent) and its activity increased in response to an episode of acute heat stress.

Acute Disease↗
PubMed1975

Observations on the sites of respiratory evaporation in the fowl during thermal panting.

The rate of respiratory water loss (RWL) was investigated in domestic fowls by the open-flow method, and the relative importance of the surfaces of the upper and lower respiratory tract was assessed by cannulating the trachea and by recording the temperatures at the potential evaporating sites. Birds were exposed to Ta from 20 to 40 degrees C and RWL examined at rectal temperatures (Tre) from 41 to 44 degrees C. Overall, the increase in RWL from the whole tract, and from the upper and lower divisions, was by about 1.1, 1.0 and 0.3 mg (g-hr. degrees C)-1, respectively. There was a rapid increase in V and in RWL from the whole and from the upper tract at Tre 41.5-42.5 degrees C, but no comparable change from the lower tract. Temperatures significantly below Ta and Tre (both 43 degrees C) were detected in the trachea and in the nasal and buccal cavities, but not in the air sacs. It was concluded that respiratory evaporation occurs mainly from the upper tract during panting and that the air sacs are unlikely to be involved.

Animals↗
PubMed1975

The functional anatomy of the pulmonary circulation of the domestic fowl.

The architecture of the pulmonary circulation in the domestic fowl was studied in 30 birds of different breeds by injection techniques and serial sections. The branches of the cranial, caudomedial and caudolateral rami of the pulmonary artery form interparabronchial arteries which are essentially transverse to the long axis of the parabronchi. At the periphery of the parabronchus they give rise to intraparabronchial arterioles which form capillaries in the exchange tissue. Most of the capillaries drain into atrial veins via intraparabronchial venules. The atrial veins lie near the parabronchial lumen below the interatrial septa. Some of the capillaries empty into septal venules which form a network underneath the atrial muscles and empty into the atrial veins. The atrial veins draining any particular region converge into a single intraparabronchial vein which penetrates the exchange tissue radially to join an interparabronchial vein. The interparabronchial veins contribute to the cranial and caudal radices of the pulmonary vein. The anatomical pathways of blood and gas indicate a cross-current relationship between pulmonary arterial blood and bulk parabronchial gas flow, and a counter-current relationship between capillary blood and gas in the air capillaries.

Animals↗
PubMed1982

Morphometrics of the avian lung. 1. The domestic fowl (Gallus gallus variant domesticus).

The lungs of 5 domestic fowls have been analysed electron microscopically by standard morphometric methods. The anatomical diffusing capacity has been calculated from the relevant parameters. The blood-gas barrier consisted essentially of endothelium, basal lamina, and a very thin squamous epithelial cell. Granular cells are absent and interstitial tissue is minimal. The following measurements are mean values applying to both lungs together, in the fixed state: lung volume, 25.0 cm3; total intrapulmonary blood volume, 6.9 cm3; volume of the exchange tissue, 11.6 cm3; pulmonary capillary blood volume, 3.51 cm3; pulmonary capillary haematocrit, 62.7%; total intrapulmonary air volume, 16.61 cm3; air capillary volume, 6.68 cm3; surface area of the blood-gas barrier, 2.08 m2; surface area of the barrier per unit volume of exchange tissue, 179.5 mm2/mm3; arithmetic mean thickness of the tissue barrier, 1.20 micrometers; harmonic mean thickness of the tissue barrier, 0.314 micrometers; harmonic mean thickness of the plasma layer, 0.342 micrometers. The values of the maximum and minimum morphometric diffusing capacities for the lung (DL02 m) were respectively 3.55 and 1.50 ml O2/min/mm Hg; those for the membrane (Dmo2 m) were 13.61 and 12.01 ml O2/min/mm Hg.

Animals↗
PubMed1982

Effects of temperature on the ventilatory response to inspired CO2 in unanaesthetized domestic fowl.

The influence of raised environmental temperature on the respiratory response to CO2 in awake, spontaneously breathing domestic fowl was investigated. In terms of their effects on ventilation VE temperature and CO2 were additive and non-interactive, VE being approximately 1900 ml . min-1 greater at 33 +/- 1 degree C compared to 18 +/- 1 degree C, regardless of inspired CO2 partial pressure PICO2. Temperature had no effect on the slope of the relationship between VE and both arterial and clavicular air sac PCO2. Blood and clavicular sac PCO2 were regulated within 2-3 Torr of normal at PICO2 levels below approximately 20 Torr as a result of hyperventilation but PCO2 regulation began to fail at higher PICO2. Hypercapnia induced increases in respiratory frequency f at normal temperatures but decreases in f at 33 +/- 1 degree C. There was little change in f at 25 +/- 1 degree C. The ventilatory increase in response to CO2 at 18 +/- 1 degree C and 25 +/- 1 degree C could be described by a linear relationship between VE and tidal volume VT. However, respiration departed from this pattern at temperatures above the panting threshold (32-34 degrees C). These findings are discussed in the context of central and peripheral mechanisms which may be involved in the control of rate and depth of breathing.

Animals↗
PubMed1989

The relationship between eggshell porosity and air space gas tensions measured before and during the parafoetal period and their effects on the hatching process in the domestic fowl.

The partial pressure of gases in the air space were measured before and during the parafoetal period for domestic fowl eggs of the same initial weight but varying in eggshell conductance. Embryos developed and hatched normally from eggs with a wide range of shell conductance and resultant air space gas partial pressures. Air space PO2 levels measured just before pipping ranged from 55 to 65 mm Hg in low and high conductance eggs, respectively, whilst PCO2 levels ranged from 75 to 55 mm Hg. With increasing shell conductance embryos membrane-penetrated and pipped the shell later, but hatch time was unaffected. Membrane penetration and external pipping appeared to occur in response to the partial pressures of gas in the air space but not in response to one particular level of air space PO2 or PCO2. During the parafoetal stage air space PO2 decreased at about 3.8 mm Hg/h and air space PCO2 increased at about 1.8 mm Hg/h and these rates of change were unaffected by eggshell conductance.

Animals↗
PubMed1993

Respiratory exchanges in the incubated egg of the domestic guinea fowl.

The daily O2 uptake (MO2) and CO2 production (MCO2) rates were measured in guinea fowl eggs with a wide range of mass specific shell water vapor conductance, spGH2O [0.108 to 0.365 mg.(g.Torr.day)-1], from day 10 to the end of incubation, day 28. The respiration rate showed a plateau, from day 22 to day 24, typical of a precocial bird: MO2 approximately 21.4 and MCO2 approximately 15.2 mmol.day-1. The plateau MO2 value was that predicted by allometric relation. At the plateau, respiratory exchanges appeared significantly limited by spGH2O. The limiting effect of spGH2O on respiratory metabolism began as soon as day 18 (64% of incubation time). The respiratory ratio was 0.75 at day 10, decreased to 0.65-0.66 on days 12-14 and stabilized at 0.70-0.71 on days 20-28.

Age Factors↗
PubMed1990

Ultrastructural localisation of alkaline phosphatase in the intertubular tissue of the testis in the domestic fowl.

Alkaline phosphatase activity in the intertubular tissue of the testes of the domestic fowl was examined using an ultracytochemical technique based on the lead capture method. In the interstitial tissue, the Leydig cells, transitional cells and the fibroblasts displayed enzyme activity on their cell membranes. Vacuoles located in the transitional cells were lined by reaction products of enzyme activity, whereas the vacuoles representing extracted lipid droplets and present mainly in the Leydig cells were free of enzyme activity. In the peritubular tissue the cell processes of fibroblasts showed enzyme activity on the cell membranes and in pinocytotic vesicles. Cell processes lying adjacent to blood vessels showed pronounced activity. In the blood vessel itself some activity was present in the basement membrane and the endothelium. The surface of the red blood cell showed moderate activity. The possible role of alkaline phosphatase in the transfer of hormone from the Leydig cells to the seminiferous tubules and from the seminiferous tubules to the interstitium is discussed. The myoid cells and their processes were devoid of enzyme activity.

Alkaline Phosphatase↗
PubMed1983

Sequence analysis of fowl plague virus mutant ts47 reveals a nonsense mutation in the NS1 gene.

A mutant of fowl plague virus, ts47, induces the synthesis in infected cells of a truncated NS1 polypeptide at both permissive and restrictive temperatures. Nucleotide sequence analysis of the segment coding for the NS1 polypeptide, segment 8, indicates that this aberration is due to a nonsense mutation. This mutation occurs in the region of the NS1 gene which overlaps with the NS2 gene and there is a corresponding amino acid substitution in the NS2 polypeptide. While it is not clear which polypeptide is responsible for the thermal instability of ts47, the loss of the COOH-terminal 28 amino acid residues from the NS1 polypeptide does not affect replication of the virus at permissive temperatures.

Base Sequence↗
PubMed1984

A mutant of fowl plague virus (influenza A) with an altered glycosylation pattern in its hemagglutinin.

A temperature-sensitive mutant (ts 1/1) with a defect in the hemagglutinin (HA) gene, which was obtained by undiluted passage of fowl plague virus (FPV) at 33 degrees, is described. At 33 degrees proteolytic cleavage of the abnormal HA yielded an altered HA2 (XHA2) which migrated ahead of the NS1 protein and lacked the complex oligosaccharide side chain. At the nonpermissive temperature of 40 degrees, the migration of the HA of ts 1/1 from the rough endoplasmic reticulum (RER) via the Golgi apparatus to the cell surface was rate limiting for virus maturation. The HA was only slowly cleaved and migrated during polyacrylamide gel electrophoresis ahead of the HA of wild type FPV. Some revertants of ts 1/1 exhibited the same protein pattern as the mutant, others resembled wild type FPV, while one revertant gave rise to a mixture of HA2 and XHA2 at 40 degrees. These results suggest that (1) the loss of the complex oligosaccharide side chain is not responsible for the ts phenotype, (2) the mutation is presumably not at the site where the oligosaccharide side chain is linked to the protein backbone, and (3) ts 1/1 presumably carries a mutation located in RNA segment 4, which by pseudoreversion (suppressor mutation) in the same gene leads to different ts+ phenotypes.

Animals↗
PubMed1984

Carbohydrates of influenza virus. V. Oligosaccharides attached to individual glycosylation sites of the hemagglutinin of fowl plague virus.

The carbohydrate side chains of the hemagglutinin of fowl plague virus (A/FPV/Rostock/34 (H7N1] have been localized by a procedure involving fragmentation of the polypeptide with cyanogen bromide and various proteases. The positions of the fragments were determined by radioactive labeling of the sugars and of specific amino acids. Side chains of the complex type I are attached to asparagine residues 12, 28, 123, 149, and 478. A mannose-rich (type II) side chain is linked to asparagine 406. Asparagine 231 is not glycosylated. The side chains attached to asparagine residues 12, 123, 149, and 478 contain sulfate. Glycopeptides derived by Pronase digestion from the individual attachment sites have been analyzed by their affinity to concanavalin A and Lens culinaris agglutinin. The results indicate that each glycosylation site has a typical set of heterogeneous oligosaccharides. Comparison of the glycosylation patterns of the hemagglutinins of FPV and other influenza A viruses reveals that the glycosylation sites at asparagine residues 12, 28, and 478, which are located at the base of the spike, are highly conserved. Mannose-rich side chains appear to be located preferentially at interfaces between the three monomers of a spike or between the globular and fibrous domains of a monomer.

Acetylglucosaminidase↗
PubMed1990

Codeine analgesic and morphine hyperalgesic effects on thermal nociception in domestic fowl.

The effects of codeine phosphate and morphine sulfate (2.5, 15.0, and 30 mg/ml/kg; IM) on latency of a jump response elicited by a noxious (61 degrees C) thermal stimulus were studied in White Leghorn cockerels at 15-16 days posthatch. Codeine induced a significant dose-dependent increase in jump response latency (analgesic effect), whereas morphine at each dose induced a significant decrease in jump response latency (hyperalgesic effect). Naloxone (5 mg/ml/kg) reversed the hyperalgesic effect of morphine (30 mg/ml/kg) and potentiated codeine analgesic effects. It is unlikely that codeine analgesic effects in domestic fowl reflect demethylation of codeine to morphine. These opposite codeine and morphine effects may reflect the interaction of these opiates at different populations of opioid receptors or at different substrates.

Analgesics↗
PubMed1991

Effects of selective opiate antagonists on morphine-induced hyperalgesia in domestic fowl.

Although morphine typically produces analgesia in a variety of species, recent research has identified a biological model in which morphine produces a naloxone-reversible, paradoxical hyperalgesic response to a noxious thermal stimulus in young domestic fowl. The present study examined opioid receptor-mediation of this atypical opiate effect. Patterns of morphine hyperalgesia (1.25 to 5.0 mg/kg IM) were examined on a standard hot-plate test following administration (10 micrograms/5 microliters ICV) of the mu antagonist beta-funaltrexamine, the delta antagonist naltrindole, or the kappa antagonist nor-binaltorphimine in 15-day-old White Leghorn cockerels. Respiration measures were also recorded because they are indicative of opiate effects. Morphine produced a dose-dependent decrease in mean jump latencies (i.e., hyperalgesic effect). Mu receptor antagonism attenuated this morphine-induced hyperalgesic effect. Kappa receptor antagonism attenuated morphine-induced hyperalgesia only at the highest morphine dose (i.e., 5.0 mg/kg) and delta receptor antagonism failed to attenuate morphine-induced hyperalgesia. These results suggest that morphine-induced hyperalgesia, like morphine-induced analgesia, is mediated primarily by mu receptor activation.

Analgesia↗
PubMed1992

Time-dependent codeine hypoalgesia and hyperalgesia in domestic fowl.

Recent research demonstrated that codeine produced hypoalgesia and morphine produced hyperalgesia against a noxious thermal stimulus in young domestic fowl. The bidirectional effects of these opiate agonists on nociception are inconsistent with the notion that codeine's algesic effects result through in vivo demethylation of codeine to yield morphine. In Experiment 1, the temporal pattern (15,30,60 and 120 min) of codeine (30 mg/kg) effects on thermal nociception and respiration were examined in 15-day-old cockerels. Codeine produced a time-dependent biphasic response: hypoalgesia at 15 min and hyperalgesia at 60 and 120 min. Respiration was depressed by codeine at all test intervals. To assess for opioid specificity, Experiment 2 examined the action of naloxone (5 mg/kg) on the temporal pattern (15 and 60 min) of codeine effects (30 mg/kg) on thermal nociception and respiration. Bidirectional codeine algesic effects were observed at the 15- and 60-min test intervals. Naloxone increased the codeine jump latency scores at the 15-min interval and decreased codeine jump latency scores at the 60-min interval. These results suggest that codeine engages opposed nonopioid-mediated hypoalgesic and opioid-mediated hyperalgesic nociceptive systems in this animal model. Codeine depressed respiration at both the 15- and 60-min test intervals and this respiratory depression was reversed by naloxone. These findings support the notion that codeine respiratory effects are mediated by opioid system activity.

Animals↗
PubMed1994

Opiate effects on isolation stress in domestic fowl.

In an attempt to examine the role of opioid system functioning in social attachment and isolation stress in young domestic fowl, the effects of morphine (5.0 mg/kg) and naloxone (5.0 mg/kg) were evaluated on distress vocalizations, thermal nociception, thermoregulation, and respiration following 15 min of isolation in 7-day-old White-Leghorn cockerels. Morphine decreased and naloxone increased distress vocalizations in isolated chicks. Isolation produced an increase in jump response latencies (i.e., hypoalgesia) on a standard hot-plate test. In general, morphine decreased and naloxone increased mean jump latencies in both isolated and nonisolated chicks. Isolation produced an increase in core body temperature (i.e., hyperthermia); morphine decreased and naloxone increased core body temperatures independent of the isolation manipulation. Social isolation did not affect respiration. However, morphine depressed respiration in both isolated and nonisolated chicks. These results support the notion that opioid systems modulate social attachment and isolation stress.

Analgesia↗
PubMed1994

The role of adrenoreceptors in control of stereotyped oral behavior in restricted-fed fowls.

Effects on environmentally induced oral stereotypies (object pecking and drinker-directed activity) of preferential antagonists and agonists of adrenoreceptor subtypes were examined in individually caged broiler breeder fowls subjected to chronic food restriction. Three drugs in each category were injected intravenously at three doses, and their effects compared with a saline control treatment. With the antagonists, object pecking was suppressed more by prazosin (alpha 1) and propranolol (beta) than by yohimbine (alpha 2), while drinker-directed activity showed delayed stimulation with yohimbine and propranolol. With the agonists, drinker-directed activity was suppressed more by clonidine (alpha 2) than by isoproterenol (beta) and phenylephrine (alpha 1), while object pecking was inhibited by the high doses of clonidine and isoproterenol but showed delayed stimulation with the low dose of clonidine and (nonsignificantly) the high dose of phenylephrine. Initial suppression of both oral stereotypies by the high doses of yohimbine and isoproterenol, and high and medium doses of clonidine, may have been due to sedation, because in those instances it coincided with increased sitting, an activity not normally seen. Increased standing with clonidine and the medium dose of yohimbine may also reflect sedation. When there were no significant increases in sitting or standing to indicate sedation, responses of both stereotypies were essentially the same with all three adrenoreceptor subtypes; i.e., object pecking was inhibited by the antagonist but not the agonist, while drinker-directed activity was inhibited by the agonist but not the antagonist. It is concluded that alpha 1, alpha 2, and beta adrenoreceptors are all implicated in expression of these stereotypes, and that the two activities may be differentially controlled.

Adrenergic alpha-1 Receptor Agonists↗