Showing papers on "Coturnix published in 1990"

Muscarinic cholinergic receptors in the songbird and quail brain: a quantitative autoradiographic study.

Abstract: In order to clarify the neuroanatomical basis for postulated muscarinic cholinergic control of a wide array of physiological processes in birds, the distribution of muscarinic cholinergic receptors in the brain of three avian species was investigated by quantitative autoradiography. The species consisted of two passerines (songbirds), the European starling (Sturnus vulgaris) and the song sparrow (Melospiza melodia), and one galliform, the Japanese quail (Coturnix coturnix japonica). [3H]N-methyl scopolamine (NMS), a muscarinic cholinergic antagonist was used as the ligand to label the receptors. Initial experiments demonstrated that the binding of this ligand in the three species is saturable in the nanomolar range and has a high affinity (Kd = +/- 0.6 nM). Displacement experiments revealed that three muscarinic ligands competed in an order of potency characteristic of the mammalian muscarinic receptor (i.e., atropine greater than oxotremorine greater than carbachol) for NMS binding in the avian brain. In all three species, portions of the basal ganglia, such as the parolfactory lobe and the paleostriatum augmentatum, exhibited the highest density of binding. On the other hand, the paleostriatum primitivum, the avian homologue of the mammalian globus pallidus, contained very few binding sites. Other telencephalic sites, such as the ventral and dorsal hyperstriatum, also revealed relatively high receptor density. However, the neostriatum and especially the ectostriatum showed much lower levels. In the hypothalamus, in all three species, specific binding could be observed in the ventromedial nucleus and adjacent areas. The paraventricular nucleus also showed moderate levels of binding density, especially in the two songbird taxa. At a more rostral level, the preoptic area showed low levels of binding. In the quail, the sexually dimorphic nucleus of the preoptic area was clearly outlined in the autoradiograms by the low level of binding sites compared to the surrounding areas. In the two passerine species, nuclei of the song system were identified by either high or low levels of NMS binding. High binding defined area X and the mesencephalic nucleus, intercollicularis (ICo). In contrast, the robust nucleus of the archistriatum and the magnocellular nucleus of the anterior neostriatum showed low levels of binding in comparison with the surrounding tissue. None of these nuclei were visible in the quail autoradiograms except for ICo, which appeared as in the passerines as a heavily labelled area surrounding the lightly labelled nucleus mesencephalicus lateralis pars dorsalis. In all three species, the hippocampal complex was devoid of NMS binding except for two lateral dark bands that were present along the entire rostral to caudal extent of the hippocampus.(ABSTRACT TRUNCATED AT 400 WORDS)

Melatonin does not link the eyes to the rest of the circadian system in quail: a neural pathway is involved.

Abstract: Blinding by enucleation has a dramatic effect on the circadian activity rhythm of Japanese quail. The activity patterns of enucleated birds held under 24-hr light-dark cycles are disrupted, although entrainment can persist in many birds. In constant darkness (DD), blinded birds are rendered arrhythmic. These results demonstrate that the eyes are a major component of the circadian system, and that insofar as enucleation produces arrhythmicity in DD, the eyes' role is not merely a photosensory one. The eyes of quail can synthesize and secrete the hormone melatonin, which has been implicated as a blood-borne messenger relaying timing information between elements of the circadian system in some avian species. However, the way in which the eyes communicate with the rest of the circadian system in quail appears to be neural, since (1) optic nerve section produces the same effects as blinding by enucleation on the circadian activity rhythm, and (2) eyes subjected to optic nerve section retain their ability to synthesize and secrete melatonin.

Spatial arrangement of the stages of the cycle of the seminiferous epithelium in the Japanese quail, Coturnix coturnix japonica.

Abstract: The spatial arrangement of the stages of the cycle of the seminiferous epithelium of the Japanese quail was investigated by preparing three-dimensional reconstructions of a seminiferous tubule from each of 3 quails. It was found that the stages were not distributed at random, but were arranged in a wave which spiralled helically along a seminiferous tubule. Adjacent stages in space were always adjacent numbers in the cycle of the seminiferous epithelium. Complete spermatogenetic waves were found in which all 10 stages of the cycle were in sequential order. However, in most waves the sequential order of stages was disturbed by the occurrence of modulations. The area of a cellular association varied from 4600 to 41,600 microns 2 with a mean +/- s.e.m. (3 animals) of 17,902 +/- 2614 microns 2. The number of Sertoli cells involved in an association ranged from 4 to 35, with a mean +/- s.e.m. (3 animals) of 13.5 +/- 2.8. The findings support our earlier suggestion that the kinetics of spermatogenesis in the quail are fundamentally similar to the pattern which has been described for mammals.

Nonspecific imprintability of quail to colors: response to artificial selection.

Abstract: Eleven generations of bidirectionally selecting quail (C coturnix japonica) for nonspecific imprintability to blue or red stimuli resulted in unexpectedly slow yet reliable differentiation of "Hi" and "Lo" imprintability lines Correlated changes were observed in the variances of unconditional color choices in subjects belonging to these genetic lines Implications of the data for understanding the interrelated expression of gene effects and environment effects in the development of behavior are discussed

Myosin isozyme expression in response to stretch-induced hypertrophy in the japanese quail

Abstract: When skeletal muscle is subjected to stretch it undergoes a rapid increase in muscle mass. However, the effect of stretch on the native myosin isozyme content of muscle has received attention only recently. Using the Japanese quail to investigate stretch-induced hypertrophy, we demonstrated an increase in the expression of fast myosin in the predominantly slow anterior latissimus dorsi muscle (ALD). The fast myosin content of the control quail ALD is not sufficient to be quantified on native myosin pyrophosphate gels. After 33 days of stretch, the fast myosin content (N = 10) averaged 16 +/- 11% in the stretched muscles and reached a maximum of 40%. Mean hypertrophy in the stretched muscle, as indicated by muscle weight, was 247 +/- 91% (range, 168-378%). Fast myosin was consistently expressed in muscles with hypertrophy greater than 250%. Muscle fiber size from the stretched muscles contained a greater number of fibers with small cross-sectional areas than was observed in controls. These results indicate that substantial remodeling occurs in the stretched ALD muscle of the Japanese quail.

Comparison of hypocholesterolemic activities of the bile acid sequestrants cholestyramine and colestipol hydrochloride in cholesterol fed SEA quail.

Abstract: The pharmacopolymer bile acid sequestrants cholestyramine and colestipol hydrochloride were mixed with a diet supplemented with 0.5% cholesterol at levels of 0.25%, 0.5%, and 1.0% for cholestyramine and 0.5% and 1.0% for colestipol and fed to young, male, SEA (Susceptible to Experimental Atherosclerosis) Japanese quail (Coturnix coturnix japonica) for a period of seven days. After treatment blood was obtained by venipuncture from non-fasted animals and analyzed for serum total cholesterol concentration. Cholestyramine significantly reduced total cholesterol concentrations at all doses in a dose dependent manner. Colestipol significantly reduced total cholesterol only at the 1.0% dose. Based on these observations, cholestyramine is significantly more potent for reducing serum cholesterol in hypercholesterolemic male SEA quail than is colestipol hydrochloride.

Renal carbonic anhydrase in the quail Coturnix coturnix japonica: I. Activity and distribution in male and female metanephros.

Abstract: Carbonic anhydrase activity was studied in the quail metanephros by means of histochemical, histophotometrical and biochemical methods. Male and female samples were examined separately in order to show sex-related differences in enzyme activity and localization. The staining patterns revealed differential distribution of reaction product in the different tubular segments. The initial portion of proximal tubules showed positivity on the brush border in female kidneys only. Extra situ investigations provided further evidence of sexual dimorphism resulting in higher values of enzyme activity for female than for male kidneys. In both sexes, marked staining was detected at the distal tubule level where histophotometric analysis confirmed the highest amount of reaction product. Moreover, the intracellular staining distribution at this site proved to be similar to that observed for mammalian proximal convoluted tubules. In the collecting ducts, a mosaic-like pattern was found with respect to both carbonic anhydrase staining and metachromatic properties. The functional significance of the presence of enzyme in the different renal tubules is discussed by comparison with the mammalian kidney. A model is proposed whereby the distal tubules represent the main sites of urinary acidification and bicarbonate reabsorption.

The subacute and subchronic toxicity of chlorophacinone in Japanese quail (Coturnix c. japonica)

Abstract: Accordingly to the subacute toxicity of chlorphacinone to Japanese quail (LC 50: 60 mg/kg feed), the uptake of Delicia-chlorphacinone-baits for several days can be lethal to birds as a matter of principle. A subchronic study resulted in a "no-observed-effect-level" of 1 mg chlorphacinon/kg feed. Reproduction is not affected until dose levels which resulted in lethality or are accompanied by physiological changes (coagulability of blood, microcytic anaemia). Increased sensibility of descendants to chlorphacinone cannot be derived from the findings.

Characterization of insulin receptors in primary cultures of quail (Coturnix coturnix japonica) oviduct cells. The level of insulin receptor is regulated by steroid and peptide hormones.

Abstract: 1. We have characterized the insulin receptor in primary cultured quail oviduct cells and examined the hormonal regulation of its level. 2. We have also shown the recycling pathway of insulin receptors in the cultured cells using specific inhibitors (tunicamycin, chloroquine, monensin, and brefeldin A). 3. Our data suggest that glucocorticoids play important physiological roles in egg-white protein synthesis through increasing the number of insulin receptors and insulin through enhancing the transport of amino acids.

Lactate dehydrogenase isozyme patterns in the denervated quail (Coturnix coturnix japonica) muscles

Abstract: Polyacrylamide gel electrophoresis of the Japanese quail (Coturnix cotunix japonica) muscle extracts revealed a single lactate dehydrogenase isozyme. A month after surgical unilateral brachiotectomy (denervation) there was significant atrophy of the triceps, biceps and radius ulnar muscles accompanied by the appearance of an additional lactate dehydrogenase isozyme band. This extra band may be the result of the synthesis of a new lactate dehydrogenase isozyme. This new isozyme exhibited a lower affinity for lactate, less sensitivity to urea denaturation and was more thermostable than the lactate dehydrogenase of normal (innervated) quail muscles. Based on these properties, it is suggested that the newly synthesised isozyme of the denervated muscles is LDH-1, (or B4/H4) type. Brachiotectomy also resulted in significant quantitative changes in the total lactate dehydrogenase activity of innervated muscles of the same animal.

Characterization of an endogenous quail intestinal lectin

Abstract: Soluble extracts of quail intestine scrapings contain a lectin activity specific for chicken and rabbit trypsinized, glutaraldehyde-fixed erythrocytes. The lectin displayed a specificity for the simple sugar haptens lactose and galactose and for mucin. Quail lectin was purified by affinity chromatography on either asialofetuin- or mucin-Sepharose, followed by DEAE-Sepharose chromatography, and demonstrated an apparent molecular weight of 14,500 on sodium dodecyl sulfate - polyacrylamide gel electrophoresis and a pI of 6.2 upon isoelectric focusing. Immunohistochemical localization of this lectin in the intestine was carried out using polyclonal antibody raised in rabbits and tested for specificity in Western blots. Immunoperoxidase staining for quail lectin showed the lectin to be prominent in secretions at the mucosal surface and in goblet cells.