Title: Hypertrophy and Altered Activity of the Adrenal Cortex in Homer 1 Knockout Mice
Abstract: Homer 1 gene products are involved in synaptic transmission and plasticity, and hence, distinct behavioral abnormalities, including anxiety- and depression-like behaviors, have been observed in Homer 1 knockout (KO) mice. Here we report that Homer 1 KO mice additionally exhibit a pronounced endocrine phenotype, displaying a profoundly increased adrenal gland weight and increased adrenal/body weight ratio. Histological examinations of Homer 1 deficient adrenal glands revealed an increased size of the adrenal cortex, especially the sizes of the <i>zona fasciculata</i> and <i>zona glomerulosa</i>. Moreover, the plasma corticosterone and aldosterone were higher in Homer 1 KO than wild-type (WT) mice while the plasma ACTH levels were not different between the genotypes. The <i>in vivo</i> ACTH test revealed that corticosterone and aldosterone plasma levels were higher in saline injected Homer 1 KO mice than in WT mice (saline injected mice served as controls for the respective groups of ACTH-injected animals), but the magnitude of steroid responses to ACTH was similar in both genotypes. In contrast, an <i>in vitro</i> experiment performed on isolated cells of adrenal cortex clearly showed increased production of both steroids in response to ACTH in Homer 1 KO cells, which is in line with an ~8-fold increase in the expression of ACTH receptor mRNA in the adrenal cortex of these mutants. These results, together with the detection of Homer 1 mRNA and protein in the adrenal cortex of WT mice, indicate that Homer 1 directly affects the steroidogenic function of the adrenal glands.
Publication Year: 2011
Publication Date: 2011-07-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
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Cited By Count: 10
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