THE ROLE OF ADRENOCORTICAL HORMONES IN THE REGULATION OF ORGANISM RESPONSE TO INTRATRACHEAL INJECTIONS OF ELECTROLYSIS DUST TO WISTAR RATS

Introduction. Adrenocortical hormones play a leading role in the adaptation of human organism to damaging factors. The aim of this study is to compare levels of cortisol and biochemical markers of organism damage (MOD) in blood samples of rats under a model of electrolysis dust (ED) inhalation exposure. ED being component of emissions in aluminum production and has high content of resinous substances (RS), including 3,4-benzpyrene. Material and methods. Male Wistar rats were injected ED intratracheally once per month, in doses corresponding to keeping of animals at ED concentrations of 1.0; 5.2 and 25.1 mg/m3, calculated on RS mass. 2 weeks after the 1st and 2nd ED administration and 6 days after the 3rd one, blood serum samples were used for determination of cortisol levels (ELISA) and the following 6 MOD: the intensity of luminol-enchanced chemiluminescence, activities of catalase, N-acetyl-β-D-glucosaminidase (NAG), acid DNAse, acetylesterase and γ-glutamyl transferase (GGT). Results. 2 weeks after the 1st and 2nd ED administrations (cortisol content 2 times reduced or not changed), similar significant changes were observed in almost all MOD; 2nd experimental point, if comparing with 1st point, had slight increase in oxidative stress and significant rise in GGT activity (a marker of precancer changes) at the maximum dose. On the contrary, 6 days after the 3rd injection of ED, in parallel with the increase of cortisol content in rat blood by 1.5 - 2 times, small significant changes were found for only one marker (NAG). The obtained data fit into existing concepts about protective role of cortisol and biphasic nature of its release into the blood, allow us to consider the absence of MOD, in parallel with rising levels of C, as a transit phase and have common problem aspects with CIRCI syndrome (Critical illness-Related Corticosteroid Insufficiency) in emergency medicine. Conclusion. Determination of cortisol levels by ELISA assay can be easily incorporated into any toxicological protocol as index of organism adaptive response, but further investigations are needed to clarify its characteristics and to build continuous model from separate time-dose points.

Gonadal and Adrenal Disorders

Adrenocortical failure most commonly is due to a decrease in production of 1 or more adrenal hormones. Clinically relevant deficiencies may involve cortisol or aldosterone or a combination of both. Decreased production of adrenocortical hormones may be a consequence of adrenocortical disease (primary failure) or tropic hormone loss (secondary failure).

Clinical and Pathological Features of Canine Metastatic Adrenocortical Carcinoma

Background: Adrenocortical carcinomas (ACC) are uncommon in dogs. ACC often invade the posterior vena cava wall and the advential layer of the abdominal aorta; however, metastases to distant organs are rare. Most dogs with ACC show clinical signs of Cushing`s syndrome in a similar way with signs reported in humans. The aim of this study is to report three cases of metastatic ACC in dogs and their clinical and pathological features.Cases: This report describes three cases of metastatic adrenocortical carcinoma (ACC) in dogs diagnosed post mortem through histopathological examination. The animals presented no signs of adrenal hormones overproduction. Case 1. A 13-year-old intact, mixed breed female dog was presented with a history of progressive hepatomegaly during the last four months. The animal was submitted to an exploratory laparotomy, but due to anesthetic complications no tissue specimen was sampled and after one week, the animal died. The necropsy examination showed an increased left adrenal (3 cm in diameter), multiple yellow to whitish nodules measuring 1 to 2 cm of diameter in the lung and severe hepatomegaly. The histopathological diagnosis was established as ACC with pulmonary metastasis. A severe and diffuse accumulation of gly­cogen in hepatocytes was also observed in Periodic acid-Schiff (PAS) staining. Case 2. A 9-year-old female intact, mixed breed dog was presented showing ataxia, left head-tilt and dyspnoea. The clinical signs progressed and the dog died after four days. The gross examination showed a diffuse increase of the left adrenal gland (2 cm of diameter) accompanied by a yellowish colour at cut surface; diffuse bronchopneumonia and cerebral and renal discrete congestion. The microscopi­cal diagnosis was ACC with kidney and CNS metastasis. Case 3. A 16-year-old male, intact, Poodle dog was presented with apathy, anorexia, vomiting and diarrhoea in the last two days. The animal was submitted to treatment, but the clinical signs progressed and the dog died. In the necropsy exam an increased right adrenal gland was observed (5 cm of diameter) showing multiple yellowish nodules when sectioned. The lung showed multiple whitish nodules mainly in pleural region. In the histopathological examination, the definitive diagnosis was ACC with pulmonary metastasis.Discussion: Most of adrenocortical tumours in dogs are functional and secrete excessive amounts of cortisol; therefore commonly animals show clinical signs of Cushing`s syndrome. In the present cases, the animals showed no clinical evidence of hormonal changes. Well-differentiated neoplastic cells were observed in cases 1 and 2, whereas in case 3 tumorous cells showed marked features of malignancy as cellular pleomorphism, binucleation, high mitotic index and atypical mitosis. Despite mild anaplastic features observed on cases 1 and 2, animals showed focus of metastases in lung, kidney and CNS. Apparently features of malignancy in ACC were not associated to the risk of metastasis development, indicating that even well-differentiated ACC may metastasize to distant organs. Metastases of ACC to distant sites are rare in dogs and there was no previous report of metastasis to CNS as observed in case 2. Canine ACC are considered uncommon tumours, how­ever, they should be included in the differential diagnosis of mass in the abdominal cavity since the animals may show no clinical signs of adrenocortical hormones overproduction.Keywords: adrenal tumours, adrenocortical hormones, metastases, dog.