Acaricide treatment prevents adrenocortical hyperplasia as a long-term stress reaction to psoroptic mange in cattle

2015 ◽  
Vol 207 (1-2) ◽  
pp. 125-133 ◽  
Author(s):  
A. Blutke ◽  
P. Börjes ◽  
N. Herbach ◽  
K. Pfister ◽  
D. Hamel ◽  
...  
1984 ◽  
Vol 4 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Pierre Lacombe ◽  
Jacques Seylaz

The question of the significance of the cerebrovascular effects of stressful situations in animals is still controversial. In the present article, an experimental model of immobilization stress in the rabbit is described, and its specificity in relation to arterial blood pressure and PaCO2 is investigated. CBF was measured with the multiregional tissue sampling technique using [14C]-ethanol as tracer. After dissipation of althesin anesthesia, the stress reaction was elicited by tactile abdominal stimuli. The response was evidenced by an instantaneous acute hypertension (+ 33.8% during the CBF measurement period). Within the first minute of the reaction, the CBF was significantly increased in all nine structures studied by 39% (caudate nucleus) to 82% (parietotemporal cortex). The study of the influence of arterial blood pressure and the PaCO2 on CBF showed that cerebrovascular autoregulation and CO2 sensitivity were differently affected in the various structures during the stress reaction. However, the stress response of the brain circulation could not be entirely ascribed to one or both of these two systemic factors, thus suggesting the contribution of a local intrinsic activation. The model presented here could be useful for long-term studies of cerebrovascular repercussions of repeated acute hypertensions of a stressful nature.


2017 ◽  
Vol 83 ◽  
pp. 14
Author(s):  
Elin Arvidson ◽  
Anna Sjörs ◽  
Ingibjörg H. Jonsdottir

Author(s):  
L.D. Stakhurlova ◽  
◽  
I.D. Svistova ◽  

Application of nitrogen fertilizers did not significantly affect the number of micromycetes. The restructuring of the species structure of the mycobiome did not exceed the adaptive zone of “stress” – a change in the frequency of occurrence of typical species. Typical types of leached chernozem micromycetes include deuteromycetes of the genera Aspergillus, Penicillium, Trichoderma, Gliocladium, Humicola, Fusarium, zygomycetes (genus Rhizopus), ascomycetes (genera Thalaromyces, Chaetomium). On average, the density of dominant species of micromycetes increased by 20 %, which indicates the development of the “dominance concentration” of typical species and a decrease in the share of rare and random species of fungi in the mycocomplex. In the experiment variants, the density of Penicillium daleae, P. funiculosum, Fusarium solani, and Aspergillus ustus species increased compared to control. These types of micromycetes are toxigenic and synthesize broad-spectrum mycotoxins (fungicidal, antibiotic, and phytotoxic). As a result, the phytotoxic activity of the soil increased to 7 and 20 % (native soil) and to 19-34 % (initiated microbial community). More pronounced changes were observed in the variant with ammonium sulfate. Thus, nitrogen fertilizers at a dose of N90 cause a “stress” reaction of the mycobiome, an increase in the share of toxigenic species and phytotoxic activity of leached chernozem. With long-term systematic use of nitrogen fertilizers, even in medium doses, it is possible to reduce the potential fertility of chernozems.


2015 ◽  
Vol 18 (1) ◽  
pp. 71-78 ◽  
Author(s):  
M. Cieślak ◽  
N. Chmielewska ◽  
K. Romanowicz ◽  
J. Młynarczuk ◽  
M. Wańkowska

Abstract The influence of early weaning on the cortisol, follicle-stimulating hormone (FSH), luteinizing hormone (LH) and growth hormone (GH) secretion in lambs of both sexes and testosterone (T4) level in male lambs during the postnatal transition to puberty was investigated by radioimmunoassay. It was hypothesized that this influence is long-term and sexually dimorphic. Hence, the effect of weaning at 5 weeks of age in comparison with the weaning at 9 weeks of age on hormone concentrations in peripheral blood plasma of 5-, 9-, 12-, and 16-week-old lambs of both sexes was investigated. The cortisol concentrations were greater (P<0.05) in control and early weaned female lambs than in male lambs at investigated stages. Weaning at 5 weeks of age resulted in the lover (P<0.05) cortisol secretion in male lambs in contrast to the greater (P<0.05) cortisol secretion in female lambs at 16 weeks of age. Weaning at 5 weeks of age stimulated (P<0.001) the FSH secretion, but reduced (P<0.001) the LH, GH and T4 secretion in 16-week-old male lambs. In female lambs early weaning inhibited (P<0.05) the FSH secretion at 9 weeks of age, LH secretion after 9 weeks of age and GH secretion after 12 weeks of age. Thus, early weaning results in the sexually dimorphic stress reaction that is more potent and long-lasting in female in contrast to male lambs. This maternal deprivation stress contributes to the inhibition of LH and GH secretion in lambs of both sexes and T4 secretion in male lambs during the postnatal transition to puberty.


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