POD-1/Tcf21 overexpression reduces endogenous SF-1 and StAR expression in rat adrenal cells

During gonad and adrenal development, the POD-1/capsulin/TCF21transcription factor negatively regulates SF-1/NR5A1expression, with higher SF-1 levels being associated with increased adrenal cell proliferation and tumorigenesis. In adrenocortical tumor cells, POD-1 binds to the SF-1 E-box promoter region, decreasing SF-1 expression. However, the modulation of SF-1 expression by POD-1 has not previously been described in normal adrenal cells. Here, we analyzed the basal expression of Pod-1 and Sf-1 in primary cultures of glomerulosa (G) and fasciculata/reticularis (F/R) cells isolated from male Sprague-Dawley rats, and investigated whether POD-1 overexpression modulates the expression of endogenous Sf-1 and its target genes in these cells. POD-1 overexpression, following the transfection of pCMVMycPod-1, significantly decreased the endogenous levels of Sf-1 mRNA and protein in F/R cells, but not in G cells, and also decreased the expression of the SF-1 target StAR in F/R cells. In G cells overexpressing POD-1, no modulation of the expression of SF-1 targets, StAR and CYP11B2, was observed. Our data showing that G and F/R cells respond differently to ectopic POD-1 expression emphasize the functional differences between the outer and inner zones of the adrenal cortex, and support the hypothesis that SF-1 is regulated by POD-1/Tcf21 in normal adrenocortical cells lacking the alterations in cellular physiology found in tumor cells.

Chronic stress effects on adrenal cortex cellular proliferation in pregnant rats / Efectos del estrés crónico sobre la proliferación celular en la corteza suprarrenal en ratas preñadas

Chronic stress by immobilization during pregnancy may cause alterations in mechanisms maintaining homeostasis in the adrenal gland. The objective of this study was to quantify cellular proliferation index in the adrenal cortex during pregnancy second half and assess the effects of chronic stress on it. Adrenal cortex proliferation index in stressed rats showed a significant decrease at 12 and 17 days of gestation, while at day 21 it did not show differences with the control treatments. Moreover, proliferation index of reticular zones in control and experimental rats, exhibited a significant reduction in comparison to glomerular and fascicular zones of adrenal cortex during the three gestation days studied. In conclusion, chronic stress by immobilization produces a decrease in cellular proliferation index at 12 and 17 gestation days, which may be related to changes in plasmatic concentrations of corticosterone and prolactin and, to the reduction of specific growth factors. Furthermore, the observed proliferation diminishment in reticular zone regarding the other cortical zones would be consistent with the migration theory of adrenal cells.

El estrés crónico por inmovilización durante la gestación puede provocar alteraciones de los mecanismos que mantienen la homeostasis en la glándula adrenal. El objetivo de este trabajo fue cuantificar el índice de proliferación en la corteza adrenal durante la segunda mitad de la gestación y comprobar los efectos que produce el estrés crónico sobre el mismo. El índice de proliferación en la corteza adrenal de ratas estresadas presentó una disminución significativa a los 12 y 17 días de gestación, mientras que en el día 21 no presentó modificaciones con respecto a sus controles. Por otro lado, el índice de proliferación de la zona reticular en ratas controles y experimentales, presentó una disminución significativa con respecto a las zonas glomerular y fascicular de la corteza adrenal en los tres días de la gestación estudiados. Se puede concluir que el estrés crónico por inmovilización produce disminución del índice de proliferación celular a los 12 y 17 días de la gestación que podría estar en relación con las variaciones de las concentraciones plasmáticas de corticosterona, prolactina, y con la disminución de factores de crecimiento específicos. Asimismo, la disminución de la proliferación en la zona reticular en relación con las otras zonas corticales estaría en concordancia con la teoría de la migración celular adrenal.

Corticosteroid physiology and principles of therapy.

The adrenal cortex secretes glucocorticoids (GC), mineralocorticoids (MC) and androgens. GC maintain homeostasis, MC regulate fluid and electrolyte balance and adrenal androgens contribute to development of secondary sexual characteristics. Pharmacologic GC therapy is frequently indicated in the pediatric age group. Besides having many important side effects, prolonged high dose systemic GC therapy has a suppressive effect on endogenous steroid production. Therefore, GC therapy should be withdrawn gradually and stopped based on assessment of hypothalamo-pituitary-adrenal (HPA) axis recovery. Patients with HPA axis suppression require physiological replacement of GC along with enhancement of doses during periods of stress. Due to its immunosuppressive effects, issues about safety and efficacy of live virus vaccines in patients receiving systemic high dose GC therapy must be borne in mind.

Age-related changes in the in vivo adrenocortical production of cAMP and corticosterone in response to exogenous ACTH in long-evans female rats

Ageing effects on the in vivo cyclic 3, 5'- adenosine monophosphate [cAMP] production by the adrenal cortex were studied in the rat. Materials and Methods: Eleven old [from 23 to 29 months] and 13 young [from 4 to 5 months], dexamethasone pre-treated Long-Evans female rats received 5.0 mu.i. [1-24] ACTH/100g b.w. by intravenous injection. The plasma concentration of corticosterone as well as the adrenal contents in cAMP and corticosterone were measured, by radioimmunoassay, just before and 45 min after the [1-24] ACTH injection. Results: The basal plasma corticosterone level and the adrenal contents in corticosterone and cAMP were low and no group difference was observed. The [1-24] ACTH injection causes significant increases in the plasma corticosterone level and the glandular contents in corticosterone and cAMP, which were lesser in the old animals than in the young ones; the differences aged/young were approximately -37%, -18% and -55% respectively. Conclusions: These results suggest that the reduced stero‹dogene response of the adrenal cortex in the old rat, to an acute ACTH administration is at least partly due to a decrease in the cellular production of the principal second messenger of this hormone, i.e. the cAMP

Adrenocortical involvement during diverse stress in soft-shelled turtle Lissemys p. punctata Bonnoterre.

Adrenocortical responses to diverse stressful situations (dehydration, formaldehyde treatment and salt loading) were studied in the adult female soft-shelled turtle, Lissenmys p. punctata. Dehydration, formaldehyde treatment (formalin, 1%: 0.1 ml/100 g body weight daily) or salt loading (NaCl, 1%: 0.1 ml/100 g body weight daily) treatments consecutively for 7 days caused hypertrophy of the adrenocortical cells with their nuclear diameter increased, and depletions of adrenal cholesterol and ascorbic acid concentrations followed by decreased acid phosphatase and alkaline phosphatase activities in turtles. Corticosterone levels were elevated in both the adrenal gland and serum of turtles after dehydration and formalin stress, but the hormone level remained unaltered after salt loading in turtles. The results suggest active involvement of adrenal cortex in stress for homeostasis in Lissemys turtles.

Effects of prednisolone on eosinophils, IL-5, eosinophil cationic protein, EG2+ eosinophils, and nitric oxide metabolites in the sputum of patients with exacerbated asthma

Corticosteroids are considered to be one of the most effective medicine for asthma by suppressing airway inflammation. This study was carried out to investigate the effects of prednisolone in the sputum of exacerbated asthmatics. Clinical severity, cell differentials, levels of interleukin (IL)-5, eosinophil cationic protein (ECP), EG2+ eosinophils, and nitric oxide (NO) metabolites were measured. Sputum was examined 2 weeks apart in 13 exacerbated asthmatics before and after prednisolone treatment, and once in 12 stable asthmatics. We used a sandwich ELISA for IL-5, fluoroimmunoassay for ECP, immunohistochemical staining for EG2+ eosinophils, a NO metabolites assay using modified Griess reaction. Exacerbated asthmatics, in comparison with stable asthmatics, had significantly higher proportion of eosinophils, higher level of ECP, higher percentage of EG2+ eosinophils, and NO metabolites. Exacerbated asthmatics after treatment with prednisolone had reduced the proportions of eosinophils, reduced level of IL-5, ECP and percentage of EG2+ eosinophils. FEV1 was correlated with the proportion of eosinophils, ECP, and IL-5 respectively. These findings suggest that prednisolone is considered to be effective medicine for asthma by suppressing eosinophil activation through IL-5.

Adrenal cytochrome-C-oxidase and P-450 in male adult rats: effects of testosterone, castration and dexamethasone

Las enzimas citrocromo-c-oxidasa y P-450 fueron mediadas en cortezas adrenales de ratas macho adultas en cuatro condiciones experimentales: G1, controles; G2, castrados; G3, castrados y tratados con testosterona y G4, castrados y tratados con testosterona y dexametasona. Con la citocromo-c-oxidasa no se observaron diferencias significativas entre G1, G2 y G4. La máxima actividad se encontró en el grupo G3, el cual difiere significativamente del resto de los grupos. Con citocromo P-450 no se encontraron diferencias entre G1 y G3. Sin embargo, se encontraron diferencias significativas entre G1 y G4. Estos estudios proveen nuevas evidencias con referencia a la interacción de la corteza adrenal y las gónadas en relación con la actividad esteroidogénica y respiratoria

Padronizaçäo das concentraçöes de esteróides no líquido amniótico: II. Testosterona, sulfato de deidroepiandrosterona e cortisol / Standardization of steroid concentrations in the amniotic fluid: II. Testosteroni, dehydroepiandrosterone sulfate and cortisol

As dosagens de testosterona, sulfato de deidroepiandrosterona (SDHEA) e cortisol no líquido amniótico (LA) permitem avaliar as funçöes das adrenais e das gônadas fetais. Estudamos LAs de 41 gestaçöes, obtidos por amniocentese no segundo trimestre da gestaçäo. Trinta e sete destas gestaçöes (das quais quatro de risco para hiperplasia adrenal congênita por deficiência da 21-hidroxilase) resultaram em fetos normais, três foram anencéfalos e um, portador de deficiência da 21-hidroxilase. Os esteróides foram dosados utilizando-se radioimunoensaio previamente descritos para dosagens séricas. Valores médios (ñ DP) destes esteróides no LA de gestaçöes com fetos normais foram testosterona: 76 ñ 34 ng/del; SDHEA: 22 ñ 9 ng/ml; cortisol 19 ñ 8 ng/ml. LAs de gestaçöes que resultaram em anencéfalos apresentaram concentraçöes de SDGEA e cortisol significativamente mais baixas em relaçäo aos normais. Testosterona foi mais baixa em fetos femininos quando comparados aos masculinos normais e discretamente mais elevada que o normal no feto feminino afetado.Näo houve diferença no valor destes esteróides ao compararmos LAs de fetos de risco para a deficiência da 21-hidroxilase com os normais. Assim, a dosagem destes esteróides näo contribui de modo definitivo para o diagnóstcio de defeitos de síntese adrenal ou de anencefalia. Também näo permitem definir com segurança o sexo fetal

Hipervitaminose A experimental no rato: estudo morfológico e morfométrico do cortex e da medula da adrenal / Experimental hypervitaminose A in the rat. Morfological and morfometric study of the cortex and medular of the adrenal

A administraçäo de 200 U. I. de vitamina A/grama de peso corporal, no rato, permitiu aos autores observarem: 1) O peso da glândula adrenal apresentou-se maior no animal com hipervitaminose A (19,58 mg) quando comparado ao animal controle (10,86 mg); 2) A zona glomerulosa do côrtex adrenal do rato tratadfo apresentou-se histologicamente, com células ligeiramente mais volumosas e com citoplasma mais abundante, mais acidófilo e com núcleos pouco mais volumosas. As zonas fasciculada a reticular também apresentaram células mais volumosas, com citoplasma mais abundante, com maior número de vacúolos e núcleos de volume maior, além de vasos bem dilatados; 3) A medula adrenal no animal tratado, revelou células com citoplasma menos granuloso, vasos dilatadores, congestos e edema. Os dados acima foram confirmados com o emprego de técnicas morfométricas