Impact of recurrent hypoglycemic stress on hindbrain A2 nerve cell energy metabolism and catecholamine biosynthesis: Modulation by estradiol

5Citations
Citations of this article
8Readers
Mendeley users who have this article in their library.

Abstract

It is unclear if habituation of hindbrain A2 metabolo-sensory neurons to recurrent insulin-induced hypoglycemia (RIIH) correlates with estradiol-dependent adjustments in energy metabolism that favor positive energy balance. Laser-microdissected A2 cells from estradiol-or oil-implanted ovariectomized female rats were analyzed by Western blot to assess effects of three prior daily insulin injections on basal and hypoglycemic patterns of catecholamine biosynthetic enzyme dopamine-beta-hydroxylase (DβH) and rate-limiting energy pathway enzyme protein expression. Precedent hypoglycemia respectively decreased or increased baseline DβH expression in estradiol- (E) vs. oil (O)-treated rats; this protein profile was further suppressed or augmented in those animals at 2 hr after re-induction of hypoglycemia. These data suggest that estradiol may curtail A2 noradrenergic-controlled functions both in the midst of and between hypoglycemic bouts. Results also show that prior hypoglycemia exposure upregulated A2 neuron glycolytic enzyme protein levels when E was present, and exerted differential effects on basal and hypoglycemia-associated respiratory chain and fatty acid synthetic pathway enzyme expression. E may thus accordingly amplify glycolysis-derived metabolites/energy, coupled with reduced reliance on oxidative phosphorylation, and activate the fatty acid synthetic pathway during RIIH. E may also be of benefit by preventing maladaptive reductions in A2 neuron Krebs cycle/electron transport enzyme expression during re-exposure to hypoglycemia. Augmentation of negative energy balance during this recurring metabolic stress in the absence of E is a likely impetus for augmented vs. decreased A2 signaling of energy imbalance by DβH in O vs. E rats during RIIH.

Cite

CITATION STYLE

APA

Tamrakar, P., & Briski, K. P. (2017). Impact of recurrent hypoglycemic stress on hindbrain A2 nerve cell energy metabolism and catecholamine biosynthesis: Modulation by estradiol. Acta Neurobiologiae Experimentalis, 77(1), 31–44. https://doi.org/10.21307/ane-2017-034

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free