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Global warming causes an increased ambient temperature and prolonged heatwaves during the summer, which represent stressogenic factors affecting the hypothalamo-pituitary-adrenocortical (HPA) axis in mammals. The aim of this study was to investigate the effects of long-term (7-60 days) exposure to moderately elevated ambient temperature (35 ± 1°C) on the histological aspect and secretory ability of pituitary adrenocorticotropic (ACTH) cells, as well as on the corticosterone output, in adult rats. Stereological parameters of ACTH cells were estimated upon immunohistochemistry. The blood concentrations of ACTH and corticosterone were determined by immunoassays. The volume of ACTH cells in rats exposed to moderately high temperature for 7, 14, 21, 30 and 60 days decreased (p

The aim of this study was to examine the effects of heat stress (HS) on the pituitary-adrenal axis and whether the treatments with early-age thermal conditioning (ETC) and vitamin C, alone and in combination, could have a beneficial effect in alleviating these effects. For the experiment, 400 one day-old broilers (both sexes) were used, being divided into four groups. The first group was the control (K), the second group (C) consisted of broilers which received vitamin C from the 22nd to the 42nd day via water in the amount of 2.00 g L-1, in the third group (T), broilers were exposed to ETC for a period of 24 hr at a temperature of 38.00 ± 1.00 °C and the fourth group (T + C) was the combination of T and C groups. Immunohistochemically positive adrenocorticotropic hormone (ACTH) cells of broilers in all groups were irregular or stellate and distributed in the periphery and central parts of the pituitary gland, as solitary cells or in clusters. In the T + C group of broilers, a significant increase in the area of ACTH cells (18.91%) and their cores (22.75%), and cortisol level in serum compared to the control group was observed. This reaction of broilers in the T + C group facilitated their adaptation to unfavorable consequences of HS. These results suggest that hypothalamic-pituitary-adrenal axis is stimulated after the exposure to chronic HS, enabling successful adaptation of broilers to adverse conditions. [ABSTRACT FROM AUTHOR]

Copyright of Acta Medica Medianae is the property of Acta Medica Medianae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Medica Medianae is the property of Acta Medica Medianae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Medica Medianae is the property of Acta Medica Medianae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Medica Medianae is the property of Acta Medica Medianae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background/Aim. Myocardial bridges (MB) are narrower or wider fascicles of the atrial or ventricular muscle fibres which form a "bridge" either across the main trunks of coronary arteries or their major subepicardial branches. The aim of this research was to determine and present the exact frequency, morphological, morphometric and histological characteristics of the MB in the level of anterior interventricular branch (AIB) in human fetal hearts. Methods. The study was performed on 63 human fetal hearts. Images of the analyzed hearts were captured with a digital camera and afterwards morphometrically evaluated with ImageJ. Characteristic cases of the MB were dissected, sampled and further routinely processed for the subsequent histological analysis. Finally, the obtained morphometric data were statistically analyzed. Results. The presence of the MB on the AIB was proven histologically and under the magnifying glass. Myocardial bridges were found in 53.97% of the hearts. The percentage of the hearts with only one MB detected on AIB 88.24% was significantly higher than the percentage of the hearts with two MBs on the AIB (11.76%) (p < 0.001). Conclusion. We suggest that the MBs are just one anatomical variation of the fetal period as well as of adulthood. [ABSTRACT FROM AUTHOR]