Biomedical subjects

I B Antunes

Publications and source records attributed to I B Antunes.

3 recordsLinked to original sources

PubMed2006

Effects of paradoxical sleep deprivation on blood parameters associated with cardiovascular risk in intact and ovariectomized rats compared with male rats.

The purpose of this study was to investigate the effects of paradoxical sleep deprivation (PSD) on circulating lipoproteins (total cholesterol, HDL, LDL and triglycerides) in males as well as in intact and ovariectomized (OVX) female rats. The intact female rat group was sub-distributed according to the phase of the estrous cycle (proestrus, estrus and diestrus) allowing for comparison of the lipid profile with males and OVX rats. The results indicate that PSD significantly reduced cholesterol in intact females compared to OVX and male rats; it reduced triglycerides in all groups except in diestrus rats and increased HDL levels in male rats compared with the respective controls. PSD also increased LDL levels in male and OVX rats when compared to intact females. Examinations of cholesterol fractions revealed significant increases in HDL in control-OVX animals when compared to the other groups, whereas HDL was significantly increased after PSD in male rats. Such results suggest that the cardiovascular response in intact, OVX females and male rats is differentially regulated especially when such are submitted to PSD. Similarities in blood parameters observed between OVX and male rats are likely due to the suppression of ovarian hormone release after ovariectomy.

Animals↗

PubMed2006

Effects of progesterone on sleep: a possible pharmacological treatment for sleep-breathing disorders?

Progesterone is present in a wide spectrum of biological activity within a variety of tissues. This hormone is also known to affect reproduction, sleep quality, respiration, mood, appetite, learning, memory and sexual activity. Progesterone exerts a sleep induction or hypnotic effect and is a potent respiratory stimulant that has been associated to a decrease in the number of central and obstructive sleep apnea episodes in men. The literature also contains a substantial amount of data on the effect of apnea in women with obesity-hypoventilation during menopause. This review attempts to outline the specific role of progesterone in normal sleep and breathing as well as its possible therapeutic effects in the treatment of sleep-disordered breathing.

Female↗

PubMed2005

Sleep pattern in rats under different stress modalities.

The present study was designed to evaluate the sleep pattern of rats submitted to chronic stressors (restraint, electrical footshock, swimming and cold) applied to male rats. After 48 h-baseline recording, rats were submitted to 4 days of chronic stress, and electrocorticogram recordings were carried out continuously. The stressors (footshock, swimming and cold) were applied twice a day for periods of 1 h at 9:00 and 16:00 h. Restrained animals were maintained in plastic cylinders for 22 h/day. The findings indicated that sleep efficiency, slow wave sleep (SWS) and paradoxical sleep (PS) were decreased on the third and fourth days of unpredictable shocks compared to baseline while immobilization and swimming presented reduced sleep efficiency in all 4-day recordings. Swimming led to decreased SWS, whereas augmented PS was observed on the first day compared to baseline. Immobilization produced drastic alterations in sleep patterns since it reduced SWS during the 4 days and PS at days 1 to 4 in relation to baseline. Of all stressors, cold was the only one that did not result in any statistical differences in sleep pattern during the light periods. Regarding the effect of stress compared to baseline on the dark recordings, PS was higher during cold stress periods, whereas footshock increased PS on days 2 to 4 and swimming only on day 2. Immobilization decreased PS throughout the 4 days of the stress sessions. Thus, the data suggest that different stress modalities result in distinct sleep responses, with immobilization producing the most dramatic alterations.

Animals↗