Plasma Β-Endorphin and Cortisol Profiles around Periparturient Period at Stressful Conditions in Egyptian Buffalo

The study determined the level of plasma β-endorphin and cortisol concentrations in peripheral blood circulation of buffalo cows suffering from reproductive disorders (dystocia and retained placenta) and weakness body condition score during periparturient period. Twenty multi-parous Egyptian buffalo cows at late pregnancy period were used for two months before parturition. β-endorphin concentrations were higher in buffalo suffering from reproductive disorders groups. Whereas, β-endorphin concentrations were 134.9±4.8 for retained placenta, 121.3±4.9 for dystocia, 114.2±8.4 for weakness and 113.5±6.5 pg/ml for control. In the closer period around parturition both of plasma β-endorphin and cortisol followed the same trend toward a gradually increased values during -2,-1days and zero time in all groups. A concomitant trend was noticed in β-endorphin and cortisol concentrations in postpartum period with reduce values were observed in all groups after parturition continued for month or more. Buffalo suffering from reproductive disorders were showed a high relative values in β-endorphin and cortisol concentrations. A significant differences (P<0.01) were observed between the experimental groups. Generally, buffaloes suffering reproductive disorders had a clear impact on blood plasma β-endorphin concentration around parturition process.The aim of this study was to determine the relationship between various reproductive disorders as a stress factors with plasma β–endorphin and cortisol in buffalo cows around parturition and changes in these parameters could be used as an objective measure of the stress associated labour. Stress has been hypothesized to be a cause of impaired reproductive efficiency. Stress may cause an overproduction of beta-endorphins and free radical

Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate

<p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr^III(HIDA)(IDA)(H₂O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO₄^-] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr^III(IDA)(Val)(H₂O)₂] and [Cr^III(IDA)(Arg)(H₂O)₂] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃(1.82 × 10^-3s^-1), is greater than the value of <it>k</it>₁(1.22 × 10^-3s^-1) for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺at 45.0°C and <it>I </it>= 0.20 mol dm^-3. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO₄^-to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃, is greater than the value of <it>k</it>₁for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p

Maturation in the female eastern king prawn Penaeus plebejus from coastal waters of eastern Australia, and considerations for quantifying egg production in penaeid prawns

The trawl fishery for eastern king prawns, Penaeus plebejus, is of major commercial significance on the east coast of Australia. This paper describes the reproductive biology of female P. plebejus and presents new information relevant to quantifying egg production in penaeid prawn populations. The study concluded that the gonosomatic index (GSI) covaried with prawn size and was, therefore, likely to be a poor indicator of reproductive activity for penaeid prawn populations. GSI was also found to be not independent of ovary histological stage, moult stage, insemination status and parasitisation by bopyrid isopods. An histological description of ovarian development and the incidence of each stage of development is provided. This includes a description of the ovulation stage, which has not been previously recorded in naturally-occurring populations. Fifty percent of female P. plebejus were classed as mature at 42mm CL. The relationships between GSI, percent mature, and percent inseminated with size suggest that there is a decline in the capacity of large (> 60 mm CL) females to produce and fertilise eggs. The declines in both GSI and percent mature is indicative of ovarian senescence in large(o1d) females, which has not been recorded previously in penaeid prawns. An index which considers the relationships between the percent mature, fecundity and the percent inseminated with size, as well as the influence of mortality on the population, is put forward to determine the relative contribution of different size classes of females to egg production. The index suggests that females >50 mm CL contribute little to egg production, and that the bulk of eggs are produced by 35 to 48 mm CL females