Anatomy
Jovana Čukuranović Kokoris; Zoran Ružić; Zdenko Kanački; Slobodan Stojanović; Smiljana Paraš; Verica Milošević
Volume 15, Issue 3 , March 2024, , Pages 125-130
Abstract
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 ...
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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.
Fatemeh Ahmadi; Ali Mirshahi; Mehrdad Mohri; Kamran Sardari; Kamran Sharifi
Volume 12, Issue 3 , September 2021, , Pages 325-331
Abstract
To investigate the hormonal and biochemical profiles of horses with osteochondrosis dissecans (OCD), serum insulin, cortisol, triiodothyronine, thyroxine, fasting blood glucose (FBG), cholesterol, triglyceride (TG), high- and low-density lipoproteins, albumin and uric acid were measured in horses definitely ...
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To investigate the hormonal and biochemical profiles of horses with osteochondrosis dissecans (OCD), serum insulin, cortisol, triiodothyronine, thyroxine, fasting blood glucose (FBG), cholesterol, triglyceride (TG), high- and low-density lipoproteins, albumin and uric acid were measured in horses definitely diagnosed with OCD (n=19) as well as clinically normal horses (n=18). Proxies representing insulin sensitivity [reciprocal of square root of insulin concentration (RISQI)] and beta cell responsiveness [modified insulin to glucose ratio (MIRG)] were calculated. Body fat percent (BF%) was estimated according to fat depth over the rump using ultrasonography. Body condition score (BCS), weight, and waist circumference were also determined. Glucose was significantly higher and MIRG, BCS, BF% and TG were significantly lower in OCD- horses compared to control group. Based on BCS scores, horses in control group were overweight. The results of the present study, higher FBG and lower MIRG, might implicate the existence of a footmark of insulin/glucose derangement. The body mass index and muscle mass were not measured in this study; nonetheless, a lower BF% might implicate a higher body muscle mass in OCD affected horses, which were comparably underweight compared to control group. While insulin resistance does also occur in human individuals and horses with lower BF%, horses with higher muscle mass may show greater potential for exercise, which in turn, exerts greater physical pressure on cartilages. An underlying hormonal predisposition could make these horses more prone to OCD, originally triggered by mechanical pressures.
