3-D structure of mitochondrial cristae in rat adrenal cortex varies after acute stimulation with ACTH and CRH.

We attempted to determine whether acute treatment with adrenocorticotropin hormone (ACTH) and corticotropin releasing hormone (CRH) affects mitochondrial morphology, as evaluated by the HRSEM and osmium maceration methods. We quantified CRH and ACTH effects on HRSEM images in rat glomerulosa and fasciculata. After ACTH or CRH treatment, mitochondrial cristae increased the number of globular expansions, whereas mitochondrial volume decreased in glomerulosa. As the morphological variations reported may be linked to increased hormonal production, further studies using parallel measurements of circulating and tissue hormones are now in progress, and may aid in clarifying their functional significance.