Sodium oxybate increases prolactin secretion in narcolepsy patients and healthy controls

Abstract

Objective: Hypocretin deficiency causes narcolepsy and may affect neuroendocrine systems, including TSH, ACTH and LH secretion. Symptoms can be treated effectively with sodium oxybate (SXB) in many patients. This study was performed to compare prolactin (PRL) secretion in patients and matched controls and establish the effect of SXB administration on PRL and sleep in both the groups. Design: Open label intervention. Blood was sampled before and after 5 days of SXB treatment. The study was performed at the Leiden University Medical Centre, Leiden, The Netherlands. Methods: Subjects were admitted to the clinical research centre on both occasions. Patients or participants: Eight male hypocretin-deficient narcolepsy with cataplexy patients and eight controls matched for sex, age, body mass index, waist-to-hip ratio and fat percentage were enrolled. Interventions: SXB two times 3 g per night for five consecutive nights. Results: Patients and controls underwent 24 h blood sampling at 10 min intervals for measurement of PRL concentrations. The PRL concentration time series was analysed with a new deconvolution programme, approximate entropy (ApEn) and Cosinor analysis. Sleep was polygraphically recorded. Basal and pulsatile PRL secretion, as well as pulse regularity and frequency, ApEn and diurnal parameters were similar in patients and controls. SXB treatment caused similar nocturnal increase in PRL secretion, advance of the acrophase and decrease in ApEn in patients and controls. Slow wave sleep was increased to a similar extent in patients and controls. Conclusion: This detailed study did not demonstrate altered PRL secretion in hypocretin-deficient narcolepsy patients during the basal state or during SXB administration. Therefore, hypocretin signalling is unlikely to be a regulator of the lactotrophic system.

The effects of sodium oxybate on core body and skin temperature regulation in narcolepsy

“…The results of this study originate from an extensive, constant routine protocol that was described previously (Donjacour et al ., ,b, ; Fig. ).…”

Mechanisms for the Specific Properties of γ‐Hydroxybutyrate in Brain

“…In addition, endogenous natural GHB is intimately linked in many aspects to GABA neurotransmission. However, its collateral action on numerous other important signaling pathways in brain (including dopamine, acetylcholine, and opiates systems) and its neuroendocrine effects on the hypothalamic–pituitary axis (growth hormone, prolactin, and oxytocin) depict complex and multifunctional properties. Furthermore, the long‐term effects of GHB modify the expression of hundreds of genes and although the consequences of these modifications are unknown, they seem apparently not pernicious for patients treated chronically.…”

Improved vigilance after sodium oxybate treatment in narcolepsy: a comparison between in‐field and in‐laboratory measurements

“…An alternative explanation for the observed time-of-day variation might reside in the suppression of dopaminergic neurotransmission by SXB (Maitre, 1997). While SXB has largely disappeared from our body upon awakening, its suppression of dopamine has ended (Donjacour et al, 2011). Hence, from a speculative point of view, it could allow for dopamine to be released in initially high quantities, which positively affects wakefulness.…”