Pavel Výboh

Plasma thyroid hormone and growth hormone patterns in precocial Japanese quail and altricial European starlings during postnatal development

Plasma concentrations of thyroid hormones (TH) and growth hormone (GH) during postnatal development in the precocial Japanese quail (Coturnix japonica), and the altricial European starling (Sturnus vulgaris) were measured. Developmental changes in plasma TH found in the starling, differ considerably from those detected in quail. In quail rather high triiodothyronine (T3) values were measured during the first few days after hatching. Subsequently a steady decrease of plasma T3, to adult levels, was observed. Thyroxine (T4) concentrations did not change significantly during the period studied. In starlings, on day 1, plasma T3 was low and T4 was at or below the assay detection limit. An increase in concentrations of both hormones occurred between day 1 and day 5 after hatching. A gradual increase of T4 occurred afterwards, while plasma T3 levels remained nearly constant during this growing period. Plasma GH concentrations showed a similar pattern in both species. There was an increase during first days after hatching and GH concentrations peaked at day 7 in quail and day 5 in starlings. A subsequent decrease was observed in both species. Although the GH profiles in species studied were comparable, there were noticeable differences in their growth rates. Thus different developmental strategies have been reflected in different developmental patterns of TH in precocial Japanese quail and altricial European starling whereas developmental changes of GH levels were similar in both species.

Effect of restraint upon hypothalamic and adrenal catecholamines in Japanese quail.

1. Changes in catecholamine concentration after periods of restraint up to 48 h in male Japanese quail have been measured. 2. Hypothalamic catecholamines decreased after 10 min restraint. Dopamine concentration increased after 4 h and persisted to 48 h. 3. Plasma catecholamines increased after 10 min, remained high for 2 h and then decreased despite continuing restraint. Catecholamine content of adrenals slightly decreased during restraint. 4. The activity of adrenal phenylethanolamine-N-methyl transferase increased from the 4th hour of restraint.

Repeated apomorphine administration alters dopamine D1 and D2 receptor densities in pigeon basal telencephalon

When pigeons are repeatedly administered a dose of apomorphine they show an increasing behavioral response, much as rodents do. In birds this expresses itself in an augmented pecking response. This sensitization is assumed to be largely due to a conditioning process. Here we present evidence that sensitization is accompanied by an alteration of the D1 to D2 dopamine receptor densities. An experimental group of pigeons was repeatedly injected with apomorphine, and a control group with saline. The basal forebrain tissue, known to be rich in dopamine receptors, was subjected to binding assays using tritiated specific D1 and D2 dopamine receptor antagonists. There was a trend towards an increase in D1 and a significant decrease in D2 receptor densities in apomorphine-treated birds compared to the saline-treated controls. We conclude that extended apomorphine treatment modifies the D1 dopamine receptor density in the opposite manner to the D2 dopamine receptor density.

Selection of Japanese Quail for Resistance to Hypodynamy and Physiological Consequences of Selection

Ivanova I. Ye., T. A. Derendiayeva, G. I. Meleshko, Yeo Ya. Shepelev: Higher Plants in a Biological Life SupportSystemfor Man. Acta vet. Bmo 1996,65: 27-32. A model of human biological life support system (BLSS) was created with a photoautotrophic link including unicellular algae and higher plants having an equal oxygen production. This system model supported the vital activities of two people at the biomass regeneration of 92% from that consumed by them. The plant cultures studied were wheat grown on 11.25 m2 (of a total 15 m2) and several vegetable species. The total photosynthetic productivity of the plants was high, stable over the studied time span, and independent on the composition of the system. However, the grain productivity of wheat decreased periodically, and during certain harvests it decreased to almost zero. A detailed analysis revealed that this decrease was not caused by any of the systems adjacent links as a similar decrease in yield was also found in the control period with an autonomous growth of the plants in a closed volume of a chamber. Inclusion of bigher plants into BLSS led to a considerable improvement od food supply regeneration for man as compared to the previous model with only 26% regeneration effect. This inclusion did not exert any marked effect upon the general closure of the cycle. However, the biological value of the food for man was increased dramatically. This improvement is the main goal of designing and operating such BLSS systems. Regeneration. ecosystem. photosynthesis, photoautotroph link, unicellular algae. higher p.lants The prospect of long-teon existence of man outside the Earths biosphere (interplanetary flights, lunar and planetary bases) is connected with creating an artificial environment with the help of regenerating it from the products of vital activity. This environment must correspond to the evolutionarily conditioned biological needs of the humans and to provide their lives for generations. The fact of adaptive biology shows that the full-value environment for humans and other terrestrial organisms is the natural environment of the Earth. In order to recreate that environment artificially it is necessary to reproduce the mechanisms existing on Earth, i. e. to foon closed ecological systems including man. The lack of our knowledge about the natural environment of the humans prevents us from reproducing it by non-biological means, even if it were possible. The investigation of the problem of creating biological life-support systems (BLSS) of man began as early as in the 60ies. By the present time, experimental BLSS models have been created with different structures and different degrees of the cycle closure. , The creation of the systems was based on the ecological concept according to which strategy and tactics were worked out providing the organisms and populations were studied and then united into biocenoses, including also humans. The main method of solving the problem was the method of experimental modelling from the simple to the complex (Rashevski 1966).

Effects of thyroid hormones on chick embryo muscle cell culture.

The importance of thyroid hormones (TH) in the normal development of muscles has been repeatedly postulated. The effects of physiological TH doses on ornithine decarboxylase (ODC) and protein synthesis in muscle cells have been studied using cell cultures prepared from 11-day-old chick embryos. Triiodothyronine nuclear receptors in primary muscle cell culture were characterized on the basis of the specific binding analysis as a single receptor class with the equilibrium dissociation constant Kd = 1.2 +/- 0.4 x 10(-10) mol/l and binding capacity Bmax = 0.21 +/- 0.09 fmol/micrograms DNA. While the physiological amounts of both triiodothyronine (T3) and thyroxine (T4) stimulated ODC activity after 2 hr of treatment, only T3 had the same stimulatory effect after 4 hr of treatment. Twenty-four hour exposure of muscle cell culture to TH did not change ODC activity. The incorporation of [3H]leucine into proteins was elevated only after 120 hr incubation in the presence of T4. Application of T4 caused also an increase in the protein content after 24 hr.

Photodynamic Effect of Hypericin after Topical Application in the Ex Ovo Quail Chorioallantoic Membrane Model

Photosensitizing properties of hypericin are well known, and the chicken chorioallantoic membrane has previously been used to test photodynamic effects of hypericin and other substances. In our study the photodynamic effect of hypericin in the ex ovo quail chorioallantoic membrane model was evaluated. Steady-state and time-resolved fluorescence spectroscopy of hypericin solution in PEG-400 and its mixture in PBS was performed to assess and characterize the process of aggregation and disaggregation of hypericin during the drug formulation preparation. A therapeutical formulation (2 µg/g of embryo weight) was topically applied on CAM into the silicone ring. Hypericin was excited by diode laser with wavelength 405 nm, fluence rate 140 mW/cm2, and fluence 16.8 J/cm2. Hypericin in 100% PEG-400 exhibits typical fluorescence spectra with a maximum of about 600 nm, while hypericin 10% PEG-400 formulation exhibits almost no fluorescence. Time resolved spectra analysis showed fluorescence decay of hypericin in 100% PEG-400 solution with a mean lifetime of 5.1 ns and in 10% PEG 4.1 ns. Damage of quail chorioallantoic membrane vasculature after photodynamic therapy ranged from hemorrhage and vanishing of capillary vessels to thrombosis, lysis, and hemorrhage of larger vessels.The presented findings suggest that quail embryos can be used as a suitable model to test the effect of hypericin and other photodynamic compounds.