Estrogen- and Satiety State-Dependent Metabolic Lateralization in the Hypothalamus of Female Rats.
Hypothalamus is the highest center and the main crossroad of numerous homeostatic regulatory pathways including reproduction and energy metabolism. Previous reports indicate that some of these functions may be driven by the synchronized but distinct functioning of the left and right hypothalamic sides. However, the nature of interplay between the hemispheres with regard to distinct hypothalamic functions is still unclear. Here we investigated the metabolic asymmetry between the left and right hypothalamic sides of ovariectomized female rats by measuring mitochondrial respiration rates, a parameter that reflects the intensity of cell and tissue metabolism. Ovariectomized (saline injected) and ovariectomized+estrogen injected animals were fed ad libitum or fasted to determine 1) the contribution of estrogen to metabolic asymmetry of hypothalamus; and 2) whether the hypothalamic asymmetry is modulated by the satiety state. Results show that estrogen-priming significantly increased both the proportion of animals with detected hypothalamic lateralization and the degree of metabolic difference between the hypothalamic sides causing a right-sided dominance during state 3 mitochondrial respiration (St3) in ad libitum fed animals. After 24 hours of fasting, lateralization in St3 values was clearly maintained; however, instead of the observed right-sided dominance that was detected in ad libitum fed animals here appeared in form of either right- or left-sidedness. In conclusion, our results revealed estrogen- and satiety state-dependent metabolic differences between the two hypothalamic hemispheres in female rats showing that the hypothalamic hemispheres drive the reproductive and satiety state related functions in an asymmetric manner.
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
Istvan
I
Toth
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
David S
DS
Kiss
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
Gergely
G
Jocsak
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
Virag
V
Somogyi
Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary.
Eva
E
Toronyi
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
Tibor
T
Bartha
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
Laszlo V
LV
Frenyo
Division of Comparative Medicine, Yale University School of Medicine, New Haven, CT, United States of America; Department of Animal Physiology and Animal Health, Szent Istvan University Faculty of Agricultural and Environmental Sciences, Godollo, Hungary.
Tamas L
TL
Horvath
Division of Comparative Medicine, Yale University School of Medicine, New Haven, CT, United States of America; Department of Animal Physiology and Animal Health, Szent Istvan University Faculty of Agricultural and Environmental Sciences, Godollo, Hungary.
Attila
A
Zsarnovszky
D000818:Animals; D004579:Electron Transport / Q000187:drug effects / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology*; D005215:Fasting / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000187:drug effects* / Q000502:physiology; D007031:Hypothalamus / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D010052:Ovariectomy; D010085:Oxidative Phosphorylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012527:Satiation / Q000502:physiology
D004958:Estradiol