Acute heat stress and adrenal cortex: biochemical, histological and ultrastrureal study in albino rats

Stress can be defined as a state of threatened balance induced by external stressor and appear as the display of somatic, and psychic reaction, struggling to regain homeostasis. Among stressful stimuli, heat stress is an environmental factor capable of causing a wide range of physiological alteration chiefly at the level of the hopothalamic- pituitary-adrenocortical [HPA] axis. The objective of the present study was to evaluate the effect of acute heat exposure on the ACTH and cortisol levels as well as structurally and ultrastructurally changes of the adrenal cortical glands in rats. Twenty normal adult male albino rats, weighting 180-200 grams, were divided into two equal groups. Group A represented the control rats and group B acted as a heat stressed rats that were exposed to hear at 38-40[degree sign]C for sixty minutes. At the end of experiment, rats were anesthetized, blood sample withdrawn for hormonal study and suprarenal glands were dissected out and prepared for microscopical and ultrasctructural examinations. A significant increase in ACTH and cortisol levels were reported in heat stressed group when compared with control group. Light microscopic examination of suprarenal cortical layers of heat-stressed rats revealed foamy cytoplasm with pyknotic nuclear changes as compared to control rats. In addition, ultrastructure examination of group B showed mitochondrial changes in all zones especially zona reticularis, decreased number of lipid droplets in both zona fasciculate and reticularis, and prominent dilatation of smooth endoplasmic reticulum vesicles when compared with group A. In conclusion, acute heat exposure was a stressful condition affecting the suprarenal glands as evidenced by the altered biochemical hormonal levels along with both structural and ultra structural changes

Evaluation of the cytoprotective effect of cow's milk against ethanol-induced gastrointestinal toxicity in albino rats: immunohistochemical and histopathological studies

Ethyl alcohol [ethanol] is readily absorbed from all parts of the gastrointestinal [GI] tract due to its hydrophilic potential. Its biological effects in human refer to practically every organ and system. The exposure of gastric and small intestinal mucosae to ethanol produces pathological changes such as inflammatory process, hemorrhagic erosions, and even acute ulcers. Although several studies have shown that milk protein components have a wide range of biological activities, the potential role of these proteins in the GI mucosal defense system is less well elucidated. In this study, we detected the GI lesions induced by short-term oral administration of ethanol to adult albino rats, after 2 and 4 weeks. Furthermore, the protective ability of milk against these injuries was determined. The morphological damage in the stomach and small intestine was detected by histopathological examination while apoptosis [programmed cell death] in the GI mucosal cells induced by ethanol, could be detected by immunohistochemical [IHC] method using Bcl-2 protein expression in the cells. This study was carried out on 60 albino rats divided into 3 equal groups as follows: [1] Control group [received water and basic diet], [2] Ethanol group received a daily oral dose of 5ml/Kg b. w. of 50% ethanol [10[th] of the LD50], [3] Milk + Ethanol group [milk 500 mg/Kg was orally given one hour before the same dose of ethanol as in the 2[nd] group]. After 2 weeks of ethanol administration the gastric and intestinal mucosal injuries were detected histopathologically and apoptotic changes by Bcl-2 expression were moderate, whereas after 4 weeks these lesions induced by ethanol were increased in severity and accompanied by a strong expression of Bcl-2 protein which pointed to severe apoptosis [group 2]. These findings indicate that ethanol-induced GI apoptosis which is influenced by the duration of exposure. This study also showed that when animals were pretreated with milk before ethanol [group 3] there was a markedly reduction in the occurrence of GI lesions after 2 weeks and even after 4 weeks in which only mild apoptosis was detected by weak Bcl-2 protein expression. It can be concluded that milk has marked antiulcer activity and may serve to protect the GI mucosa against injuries induced by ethanol

Immunohistochemical detection of alveolar macrophages and pulmonary giant cells and their diagnostic value in some types of asphyxia

The occurrence of numerous alveolar macrophages and pulmonary giant cells has been reported in both fatal asphyxia and other causes of death Pulmonary giant cells as a significant diagnostic tool in cases of asphyxia is still a controversial discussion. In the present study we investigated experimentally some types of asphyxia to detect both alveolar macrophages and pulmonary giant cells by immunohistochemical method using a monoclonal antibody Ki-Mlp, and to estimate the frequency,. of these cells microscopically in each group examined to evaluate the statistical differences which may help in differentiation between the various causes of death from asphyxia. Forty two adult albino rats were divided into 7 groups each contained 6 animals. The first group were sacrificed by decapitation and act as a control group. The animals of the 2nd and 3rd. groups were killed by obstructive asphyxia as strangulation and hanging respectively, while those of the 4th group were asphyxiated by drowning. The 5th 6 th and 7th groups included deaths of asphyxia due to inhalation of irritant gases as methanol either and butagaz respectively. Serial sections were prepared from formalin-fixed paraffin-embedded tissue specimens of lungs and brains, and were used for Hx and E and immunostaining. Alveolar macrophages and pulmonary giant cells in all groups of asphyxia stained positively with a monoclonal antibody Ki-Mlp. The frequency of these reactive cells showed a variation between the different types of asphyxia which may be useful in. the differentiation between the asphyxiated cases as this immunostaining method was easily and rapidly performed. No histiocytes could be observed in the brain tissues which served as a good negative control