Steroidogenesis delta 5 pathway

Since Staphylococcus aureus delta toxin previously had been shown to increase the cyclic adenosine 3',5'-monophosphate (cAMP) content of guinea pig ileum, the effect of delta toxin on such cAMP-mediated responses as morphogenesis and steroidogenesis in cultured tissue cells was examined. In contrast to cholera toxin, delta toxin did not cause spindling of Chinese hamster ovary cells. Unlike adrenocorticotropin or cholera toxin, delta toxin was unable to cause rounding of Y-1 adrenal cells or to promote steroid production by the cells. S. aureus alpha toxin and enterotoxin B were also unable to cause rounding of Y-1 adrenal cells. Omission of Ca2+ from the media still allowed for increased steroid production by adrenocorticotropin but not by delta toxin. Delta toxin at concentrations greater than 10 micrograms/ml did cause lysis of both Chinese hamster ovary and Y-1 adrenal cells. These findings suggest that the increase in intestinal cAMP levels caused by delta toxin is mediated through a mechanism different from that initiated by cholera toxin.

The fetal adrenal cortex lacks expression of the enzyme early on, thus mineralocorticoids (. aldosterone ) and glucocorticoids (. cortisol ) cannot be synthesized. This is significant because cortisol induces type II pneumocytes of the lungs to synthesize and secrete pulmonary surfactant ; without pulmonary surfactant to reduce the alveolar surface tension , premature neonates may die of neonatal respiratory distress syndrome . If delivery is unavoidable (. because of placental abruption , or pre-eclampsia / HELLP syndrome ), then glucocorticoids (. cortisol) can be administered.

The OECD Guidelines for the Testing of Chemicals is a collection of about 150 of the most relevant internationally agreed testing methods used by government, industry and independent laboratories to identify and characterise potential hazards of chemicals. They are a set of tools for professionals, used primarily in regulatory safety testing and subsequent chemical and chemical product notification, chemical registration and in chemical evaluation. They can also be used for the selection and ranking of candidate chemicals during the development of new chemicals and products and in toxicology research. This group of tests covers health effects.

Steroidogenesis delta 5 pathway

steroidogenesis delta 5 pathway


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