Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Mar 2007
ReviewPhosphorylation and other conundrums of Na/Ca exchanger, NCX1.
The Na+/Ca2+ exchanger (NCX) is an important Ca2+ transport mechanism in virtually all cells in the body. There are three genes that control the expression of NCX in mammals. ⋯ Here we briefly discuss three remarkable regulatory issues or "conundrums" that involve the most prevalently expressed gene, NCX1. (1) How is NCX1 regulated by phosphorylation? We suggest that the macromolecular complex of NCX1 plays a critical role in the regulation of NCX. The role of the macromolecular complex and evidence supporting its existence and functional importance is presented. (2) Can there be transport block of a single "mode" of NCX1 transport by drugs or therapeutic agents? The simple answer is "no." A brief explanation is provided. (3) How can NCX1 knockout mice live? The answer is "by other compensatory regulatory mechanisms." These conundrums highlight important features in NCX1 and lay the foundation for new experiments to elucidate function and regulation of NCX1 and provide a context for investigations that seek to understand novel therapeutic agents.
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Ann. N. Y. Acad. Sci. · Mar 2007
Comparative StudyGender-specific differences in salivary biomarker responses to acute psychological stress.
The stress response is regulated by two primary neuroendocrine systems, the hypothalamus-pituitary-adrenocortical (HPA) and sympathetic adrenomedullary (SAM) systems. This study investigated gender differences in the activities of these two systems in response to acute psychological stress. Subjects were categorized according to their score in Spielberger's Trait Anxiety Inventory (STAI), which assesses the predisposition to personal anxiety. ⋯ There were no gender differences in amylase levels in either the high- or low-anxiety groups. However, cortisol levels in highly anxious females were significantly lower than those in highly anxious males. Our findings show that highly anxious females exhibited lower cortisol release than highly anxious males, suggesting that high trait anxiety in females may be associated with an inability to respond with sufficient activation of HPA under acute psychological stress.