The role of NPY in the mediation of orexin-induced hypothermia

Jászberényi, Miklós; Bujdosó, E.; Kiss, É; Pataki, Imre; Telegdy, Gyula

doi:10.1016/s0167-0115(01)00339-1

Cited by 32 publications

(20 citation statements)

References 33 publications

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“…Inverted U-shaped dose–response curves can cause decreased responsiveness to appear as sensitization when a single dose is tested. Because drug-induced hypothermic effects can follow inverted dose–response curves (Jaszberenyi et al 2002), the possibility exists that enhanced responsiveness to CHA is due to a rightward shift in the dose–response relationship and not sensitization. Nonetheless, we interpret the current results as evidence for increased responsiveness to CHA because (1) our hypothesis predicted that DR animals would show an increased response to CHA, (2) a decrease in resting T b supports increased sensitivity to endogenous adenosine, and (3) increased surface expression of A 1 AR is consistent with sensitization.…”

Section: Discussionmentioning

confidence: 99%

Altered thermoregulation via sensitization of A1 adenosine receptors in dietary-restricted rats

et al. 2010

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Rationale Evidence links longevity to dietary restriction (DR). A decrease in body temperature (Tb) is thought to contribute to enhanced longevity because lower Tb reduces oxidative metabolism and oxidative stress. It is as yet unclear how DR decreases Tb. Objective Here, we test the hypothesis that prolonged DR decreases Tb by sensitizing adenosine A1 receptors (A1AR) and adenosine-induced cooling. Methods and results Sprague–Dawley rats were dietary restricted using an every-other-day feeding protocol. Rats were fed every other day for 27 days and then administered the A1AR agonist, N6-cyclohexyladenosine (CHA; 0.5 mg/kg, i.p.). Respiratory rate (RR) and subcutaneous Tb measured using IPTT-300 transponders were monitored every day and after drug administration. DR animals displayed lower RR on day 20 and lower Tb on day 22 compared to animals fed ad libitum and displayed a larger response to CHA. In all cases, RR declined before Tb. Contrary to previous reports, a higher dose of CHA (5 mg/kg, i.p.) was lethal in both dietary groups. We next tested the hypothesis that sensitization to the effects of CHA was due to increased surface expression of A1AR within the hypothalamus. We report that the abundance of A1AR in the membrane fraction increases in hypothalamus, but not cortex of DR rats. Conclusion These results suggest that every-other-day feeding lowers Tb via sensitization of thermoregulatory effects of endogenous adenosine by increasing surface expression of A1AR. Discussion Evidence that diet can modulate purinergic signaling has implications for the treatment of stroke, brain injury, epilepsy, and aging.

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Section: Discussionmentioning

confidence: 99%

Altered thermoregulation via sensitization of A1 adenosine receptors in dietary-restricted rats

et al. 2010

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“…Those are findings that support orexins participation in energy homeostasis and thermoregulation (Jaszberenyi et al, 2002). Orexin A is the peptide involved in activation of food intake, its injection increases feeding and decreases body temperature (Jaszberenyi et al, 2002). Those effects of orexin A are mediated through its interaction with the NPY system (Muroya et al, 2004).…”

Section: Tshmentioning

confidence: 94%

“…Orexins-containing neurons from LHA project to the PVN (Peyron et al, 1998) where its receptors have been identified (Backberg et al, 2002). Those are findings that support orexins participation in energy homeostasis and thermoregulation (Jaszberenyi et al, 2002). Orexin A is the peptide involved in activation of food intake, its injection increases feeding and decreases body temperature (Jaszberenyi et al, 2002).…”

Section: Tshmentioning

confidence: 95%

Differential Adaptations of the Hypothalamus-Pituitary-Thyroid Axis Between Food Restriction and Anorexia

Gortari¹,

Alvarez-Salas²,

Morales-Mulia³

et al. 2012

Hypothyroidism - Influences and Treatments

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“…Moreover, the ox -/-mice show a hypometabolic phenotype (Chemelli et al, 1999). Paradoxically, hypothermic effects of OX-A after central administration have also been described as well, via a NPY-mediated mechanism (Jaszberenyi et al, 2002;Szekely et al, 2002). Curiously, one of these reports described hyperthermic effects of OX-B (Szekely et al, 2002).…”

Section: Thermogenic Actions Of Orexinsmentioning

confidence: 99%