Role of oxytocin signaling in the regulation of body weight

Abstract

Obesity and its associated metabolic disorders are growing health concerns in the US and worldwide. In the US alone, more than two-thirds of the adult population is classified as either overweight or obese [1], highlighting the need to develop new, effective treatments for these conditions. Whereas the hormone oxytocin is well known for its peripheral effects on uterine contraction during parturition and milk ejection during lactation, release of oxytocin from somatodendrites and axonal terminals within the central nervous system (CNS) is implicated in both the formation of prosocial behaviors and in the control of energy balance. Recent findings demonstrate that chronic administration of oxytocin reduces food intake and body weight in diet-induced obese (DIO) and genetically obese rodents with impaired or defective leptin signaling. Importantly, chronic systemic administration of oxytocin out to 6 weeks recapitulates the effects of central administration on body weight loss in DIO rodents at doses that do not result in the development of tolerance. Furthermore, these effects are coupled with induction of Fos (a marker of neuronal activation) in hindbrain areas (e.g. dorsal vagal complex (DVC)) linked to the control of meal size and forebrain areas (e.g. hypothalamus, amygdala) linked to the regulation of food intake and body weight. This review assesses the potential central and peripheral targets by which oxytocin may inhibit body weight gain, its regulation by anorexigenic and orexigenic signals, and its potential use as a therapy that can circumvent leptin resistance and reverse the behavioral and metabolic abnormalities associated with DIO and genetically obese models.

Beneficial Dog Bacteria Up-Regulate Oxytocin and Lower Risk of Obesity

“…Other work has shown a release of oxytocin from somatodendrites and axonal terminals within the CNS implicated in both control of energy balance the formation of prosocial behaviors [41]. Romero et al and Nagasawa et al [16,68] found that giving dogs exogenous oxytocin supplements causes them to display stronger social bonding behavior, both with people and other dogs.…”

“…Knowing that oxytocin inhibits weight gain in rodent models [21,41], and that oxytocin modulates appetite in human subjects [29], plasma levels of oxytocin were tested in mice of long-and short-term experiments. We found significantly elevated blood plasma oxytocin levels in C57BL/6 mice getting canine-source L. reuteri 2546 in their water, when compared with age-matched controls drinking regular water ( Figures 5A and 5B).…”

“…Recognizing that oxytocin inhibits weight gain in rodent models [21,41] and in humans [29], we challenged oxytocin-deficient B6;129S-Oxttm1Wsy/J mutant mice with canine source L. reuteri 2546 to determine whether this neurotropic hormone oxytocin is essential for L. reuteri 2546-induced weight control. We found that mice globally lacking oxytocin did not benefit from microbe-induced body weight Figures 5C and 5D).…”

Oxytocin in survivors of childhood-onset craniopharyngioma

“…Oxytocin has also been linked to energy homeostasis mechanisms in animals, where it acts as a strong inhibitor of food intake and affects energy expenditure and glucose homeostasis [27][28][29][30][31]. Oxytocin has also been shown to play an important role in metabolism and energy balance in humans [32,33], such as reducing caloric intake with a preferential effect on fat intake [11] and reward-driven food intake in humans [34]. These findings are in line with our finding that reduced levels of delta oxytocin correlate with a high BMI in CP patients.…”

Oxytocin Nasal Spray in the Treatment of Binge Eating Disorder and Obesity: A Pilot, Randomized, Double-Blind Trial

“…Interestingly, a large body of findings supports a prominent role for oxytocin in the modulation of food intake and body weight in animal models [5].…”