The purpose of the study was to explore parallel and divergent features of the daily rhythms of melatonin and plasma free fatty acids (FFA) in goats exposed to different lighting conditions. From these features, we attempted to analyze whether the endogenous melatonin rhythm plays any role in the maintenance of the FFA rhythm. Seven Finnish landrace goats were kept under artificial lighting that simulated the annual changes of photoperiod at 60 degrees N (longest photoperiod, 18 h; shortest, 6 h). The ambient temperature and feeding regimen were kept constant. Blood samples were collected 6 times a year at 2 h intervals for 2 d, first in the prevailing light-dark (LD) conditions and then after 3 d in constant darkness (DD). In LD conditions, the melatonin levels always increased immediately after lights-off and declined around lights-on, except in winter (18 h darkness), when the low daytime levels were restored clearly before lights-on. The FFA levels also displayed a consistent rhythmicity, with low levels at night and a transient peak around lights-on. In DD conditions, the melatonin profiles were very similar to those found in the habitual LD conditions, but the rhythm tended to advance. The FFA rhythm persisted also in DD, and the morning peak tended to advance. There was an overall parallelism between the two rhythms, with one significant exception. In winter in LD conditions, the morning rise in FFA levels coincided with lights-on and not with the declining phase of melatonin, whereas in DD conditions, the FFA peak advanced several hours and coincided with the declining phase of melatonin. From this finding and comparisons of the calculated rhythm characteristics, i.e., phase-shifts, phase differences, and correlations, we conclude that the daily rhythm of FFA levels is most probably generated by an endogenous oscillator, primarily adjusted by dawn, whereas the melatonin rhythm in this species is regulated by an oscillator primarily adjusted by dusk. The results did not exclude a modulatory effect of melatonin on the daily FFA profiles, but melatonin secretion, alone, does not explain the patterns sufficiently.

Download full-text PDF

Source
http://dx.doi.org/10.1080/07420520600650620DOI Listing

Publication Analysis

Top Keywords

ffa levels
12
melatonin
10
daily rhythms
8
rhythms melatonin
8
free fatty
8
fatty acids
8
constant darkness
8
ffa
8
melatonin rhythm
8
ffa rhythm
8

Similar Publications

Squid viscera, a byproduct of squid processing, contains oil rich in omega-3 fatty acids (up to 10% by mass) and the antioxidant astaxanthin. However, its high free fatty acid (FFA) content compromises stability. To address this, pilot-scale (200 L) enzymatic re-esterification of squid oil using immobilized lipase (Lipozyme RMIM) was demonstrated, resulting in high acylglyceride yields.

View Article and Find Full Text PDF

Free fatty acids (FFAs) are important energy sources and significant for energy transport in the body. They also play a crucial role in cellular oxidative stress responses, following cell membrane depolarization, making accurate quantification of FFAs essential. This study presents a novel supercritical fluid chromatography-mass spectrometry (SFC-MS) method using selected ion recording in negative electrospray ionization mode, enabling rapid quantification of 31 FFAs within 6 min without derivatization.

View Article and Find Full Text PDF

Background: Berberine (BBR) is widely used to treat gastrointestinal diseases. However, the pharmacological mechanism of action of BBR in anti-chronic atrophic gastritis (CAG) remains unclear. This study aimed to investigate the mechanism of action of BBR in CAG by integration of molecular biology and multi-omics studies strategy.

View Article and Find Full Text PDF

Background & Aims: Hepatic insulin resistance is a fundamental phenomenon observed in both Type 2 diabetes (T2D) and metabolic (dysfunction) associated fatty liver disease (MAFLD). The relative contributions of nutrients, hyperinsulinemia, hormones, inflammation, and other cues are difficult to parse as they are convoluted by interplay between the local and systemic events. Here, we used a well-established human liver microphysiological system (MPS) to establish a physiologically-relevant insulin-responsive metabolic baseline and probe how primary human hepatocytes respond to controlled perturbations in insulin, glucose, and free fatty acids (FFAs).

View Article and Find Full Text PDF

Background: Medications targeting the leptin and Apolipoprotein CIII (APOC3) pathways are currently under development for the treatment of hypertriglyceridaemia. Given that both pathways are implicated in triglyceride regulation, it is unknown whether they function independently or interact under physiological conditions and under acute or long-term energy deficiency.

Methods: APOC3 levels and their association with circulating lipids and lipoproteins were evaluated in the context of two randomised controlled studies.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!