Effects of systemic GHRH on sleep in intact and hypophysectomized rats

1996 ◽  
Vol 270 (2) ◽  
pp. E230-E237 ◽  
Author(s):  
F. Obal ◽  
R. Floyd ◽  
L. Kapas ◽  
B. Bodosi ◽  
J. M. Krueger
Keyword(s):  
Human Subjects ◽  
Physiological Saline ◽  
Time Of Day ◽  
Light Onset ◽  
Gh Secretion ◽  
Pituitary Growth Hormone ◽  
Hypophysectomized Rats ◽  
Cortical Temperature ◽  
Intact Rats

The role of pituitary growth hormone (GH) in the mediation of enhanced sleep elicited by GH-releasing hormone (GHRH) was studied in the rat. Intact and hypophysectomized (HYPOX) rats received systemic injections of GHRH or physiological saline. GHRH (0.5, 5.0, or 50 micrograms/kg in the intact rats and 0.5 or 50 micrograms/kg in HYPOX rats) was injected 6 h after light onset (P.M. injection) or just before light onset (A.M. injection, 0.5 microgram/kg in both A.M. groups). Sleep-wake activity and brain cortical temperature were recorded for 23 h (12 h light + 11 h dark). A.M. injection of GHRH did not alter sleep in normal or HYPOX rats. Each dose of P.M. GHRH increased rapid-eye-movement sleep (REMS) during 6 h postinjection in the intact rats. Hypophysectomy abolished the REMS-promoting activity of GHRH. P.M. injection of 0.5 microgram/kg GHRH increased non-REM sleep (NREMS) and enhanced electroencephalogram slow-wave activity during NREMS in both the intact and the HYPOX rats. The NREMS-promoting activity disappeared when the dose of GHRH was increased in the intact rats, whereas a tendency to enhanced NREMS was still observed after 50 micrograms/kg GHRH in the HYPOX rats. GHRH stimulated GH secretion dose dependently in the intact rats. A.M. injection of 0.5 microgram/kg GHRH tended to be less effective in stimulating GH release than the same dose administered P.M. The results confirm the time-of-day variations in the GHRH effects on sleep previously reported in human subjects. It is likely that pituitary GH is involved in the mediation of the REMS-promoting activity of GHRH but not in the NREMS-promoting activity of GHRH. Nevertheless, the results do not exclude the possibility that GH may modulate NREMS.

scholarly journals An ether stressor increases REM sleep in rats: possible role of prolactin

2000 ◽  
Vol 279 (5) ◽  
pp. R1590-R1598 ◽  
Author(s):  
B. Bodosi ◽  
F. Obál ◽  
J. Gardi ◽  
J. Komlódi ◽  
J. Fang ◽  
...  
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Wave Activity ◽  
Intracerebroventricular Administration ◽  
Light Onset ◽  
Hypophysectomized Rats ◽  
Sleep Alterations ◽  
Stimulation Of

Sleep alterations after a 1-min exposure to ether vapor were studied in rats to determine if this stressor increases rapid eye-movement (REM) sleep as does an immobilization stressor. Ether exposure before light onset or dark onset was followed by significant increases in REM sleep starting ∼3–4 h later and lasting for several hours. Non-REM (NREM) sleep and electroencephalographic slow-wave activity during NREM sleep were not altered. Exposure to ether vapor elicited prolactin (Prl) secretion. REM sleep was not promoted after ether exposure in hypophysectomized rats. If the hypophysectomy was partial and the rats secreted Prl after ether exposure, then increases in REM sleep were observed. Intracerebroventricular administration of an antiserum to Prl decreased spontaneous REM sleep and inhibited ether exposure-induced REM sleep. The results indicate that a brief exposure to ether vapor is followed by increases in REM sleep if the Prl response associated with stress is unimpaired. This suggests that Prl, which is a previously documented REM sleep-promoting hormone, may contribute to the stimulation of REM sleep after ether exposure.

Corticosterone-dependent driving influence of the suprachiasmatic nucleus on adrenal sensitivity to ACTH

2002 ◽  
Vol 282 (2) ◽  
pp. E458-E465 ◽  
Author(s):  
Dominique Sage ◽  
Daniel Maurel ◽  
Olivier Bosler
Keyword(s):  
Adrenal Cortex ◽  
Suprachiasmatic Nucleus ◽  
Diurnal Rhythm ◽  
Direct Evidence ◽  
Critical Role ◽  
Time Of Day ◽  
Dexamethasone Treatment ◽  
Intact Rats

We investigated the effects of ablation of the suprachiasmatic nucleus (SCN) on corticosterone (CORT) responses to synthetic ACTH given in either the morning or evening. After dexamethasone treatment, evening ACTH injections in intact rats produced a significantly larger increase in plasma CORT compared with morning ones. In rats with SCN lesions, the ACTH-induced CORT secretion was independent of time of day, providing direct evidence for a driving influence of the SCN on the diurnal rhythm of adrenal sensitivity to ACTH. In the absence of dexamethasone treatment, the SCN-lesioned rats were selected for morning-like (ML) or evening-like (EL) basal levels of CORT. Responses to ACTH were not different in ML rats compared with sham-lesioned morning controls. In contrast, EL rats compared with sham-lesioned evening controls showed an ∼60% decrease in increment of CORT levels within the first 15 min postinjection. These results indicate that the SCN upregulates ACTH sensitivity of the adrenal cortex during the ascending phase of the daily CORT secretion and point to a critical role of glucocorticoids in determining SCN action.

THE ROLE OF CORTICOTROPHIN AND OF STRESS IN THE BIPHASIC CHANGES IN FASCICULAR NUCLEOLAR SIZE IN THE RAT ADRENAL

1962 ◽  
Vol 40 (3) ◽  
pp. 364-374 ◽  
Author(s):  
Richard A. Miller
Keyword(s):  
Direct Response ◽  
Unilateral Adrenalectomy ◽  
Hypertrophic Response ◽  
Initial Effect ◽  
Hypophysectomized Rats ◽  
Nuclear Changes ◽  
Response To Stress ◽  
Nucleolar Size ◽  
Intact Rats

ABSTRACT Nucleolar and nuclear sizes were measured in the fascicular zone of the adrenals 1 to 13 hours after injecting corticotrophin, morphine, and unilateral adrenalectomy, alone and in combination in rats. One hour after injecting corticotrophin into intact rats nucleoli enlarged and then regressed briefly, only to begin a second hypertrophy extending up to 13 hours after injection. This biphasic hypertrophy occurred with different corticotrophins prepared in water, oil, or gelatine. The initial hypertrophy appeared to be a direct response to stress, not mediated by the hypophysis since it occurred in hypophysectomized rats subjected only to unilateral adrenalectomy under ether. Hypertrophy was blocked by morphine and when nembutal was substituted for ether. The late hypertrophy (4 to 13 hours) was pituitary dependent and did not occur unless hypophysectomized rats received corticotrophin. The nucleolar hypertrophy which occurred 1 hour after corticotrophin and unilateral adrenalectomy of hypophysectomized rats was less than that of hypophysectomized, unilaterally adrenalectomized controls. Moreover, when the stress response was blocked by morphine, corticotrophin caused nucleolar atrophy 1 hour later. It was concluded that the initial effect of corticotrophin is to decrease nucleolar size, but this decrease is masked usually by the hypertrophic response to stress and only becomes apparent when the stress-hypertrophy is blocked by morphine. Nuclear changes in size generally paralleled nucleolar changes. However, it was not necessary to block the stress-hypertrophy with morphine to demonstrate the initial atrophic action of corticotrophin on the nucleus. Thus, the biphasic nucleolar response to corticotrophin in intact rats appears to be the result of an interaction of stress and corticotrophin.

MECHANISM OF ACTION OF OXYTOCIN IN RETARDING MAMMARY INVOLUTION: STUDY IN HYPOPHYSECTOMIZED RATS

1961 ◽  
Vol 22 (3) ◽  
pp. 207-213 ◽  
Author(s):  
J. MEITES ◽  
T. F. HOPKINS
Keyword(s):  
Mammary Gland ◽  
Mechanism Of Action ◽  
Physiological Saline ◽  
Secretory Activity ◽  
Adrenocorticotrophic Hormone ◽  
Secretory Function ◽  
Mammary Involution ◽  
Alveolar Structure ◽  
Hypophysectomized Rats ◽  
Intact Rats

SUMMARY On the 4th day after parturition lactating rats were hypophysectomized and their litters removed. Control rats were injected only with physiological saline for the next 10 days, and showed pronounced regression of the mammary parenchyma and no secretion. When oxytocin was injected together with prolactin and adrenocorticotrophic hormone (ACTH) for 10 days, mammary secretion, often with duct engorgement, was observed in twenty-two out of twenty-four rats, whereas only three out of fourteen rats given prolactin and ACTH showed slight secretory activity. Lobule-alveolar structure was significantly better preserved in the former rats. The combination of oxytocin, prolactin and cortisol acetate was also more effective than prolactin and cortisol acetate in maintaining secretory function and in retarding mammary involution. These results in hypophysectomized rats, as well as similar findings previously reported by us in intact rats, demonstrate that the favourable effects of oxytocin in maintaining secretory activity and retarding mammary involution are exerted directly on the mammary gland.

Behavioral Symptoms in Dementia: The Role of Time of Day

2006 ◽  
Author(s):  
Ann Louise Barrick ◽  
Philip D. Sloane ◽  
Madeline Mitchell ◽  
Christianna Williams ◽  
Wendy Wood
Keyword(s):  
Time Of Day ◽  
Behavioral Symptoms

The Role of Saline Aerosols in the Prevention and Therapy of Cardio-respiratory and Osteo-muscular Afflictions

2018 ◽  
Vol 69 (10) ◽  
pp. 2826-2832
Author(s):  
Ioan Gabriel Sandu ◽  
Viorica Vasilache ◽  
Andrei Victor Sandu ◽  
Marin Chirazi ◽  
Cezar Honceriu ◽  
...  
Keyword(s):  
Athletic Performance ◽  
Gaseous Medium ◽  
Human Subjects ◽  
Active Surface ◽  
Positive Influence ◽  
Climatic Parameters ◽  
Gaussian Distributions ◽  
Gaseous Media ◽  
Source Number

The saline aerosols generated in gaseous media, as nanodispersions, behave, with respect to the concentration levels and the lifespan, as trimodal distributions (the three domains with Gaussian distributions: fine or Aitken under 50 �m, medium between 50 and 500 mm and, respectively, coarse or large between 500 and 1000 mm). The generation in latent state is dependent on the active surface of the source (number of generator centres, the size and position of the fluorescences, the porosity, size and shape of the source, etc.), the climatic parameters, but also on a series of other characteristics of the gaseous medium. Our team has demonstrated experimentally that saline aerosols, NaCl type, besides the ability to prevent and treat broncho-respiratory and cardiac conditions, through coassistance of saline aerosols of other cations than sodium, and of the iodine anion, have for certain levels of concentrations propitious effects over the immune, bone and muscular systems. Similarly proved has been the positive influence on the development of children, as well the determinant role in increasing athletic performance and of other human subjects performing intense activities.

Monosodium Glutamate Toxicity and the Possible Protective Role of L–Carnitine

2018 ◽  
Vol 6 (1) ◽  
pp. 45-56
Author(s):  
Lalrinzuali Sailo ◽  
◽  
Meesala Krishna Murthy ◽  
Khandayataray Pratima ◽  
Vikas Kumar Roy ◽  
...  
Keyword(s):  
Human Subjects ◽  
Monosodium Glutamate ◽  
Essential Amino Acids ◽  
Protective Role ◽  
Glutamate Toxicity ◽  
Common Salt ◽  
Genotoxic Effects ◽  
Naturally Occurring ◽  
Flavour Enhancer

Monosodium glutamate is naturally available non-essential amino acids, which found in naturally occurring foods and used as flavour enhancer worldwide. Monosodium glutamate is believed to be linked with diverse health problems. The aim of the study was toxic effects of monosodium glutamate (MSG) and the protective role of L-carnitine, light on the available literature from last 25 years about diverse toxicity studies which had been carried out on animal and human models. Google scholar, NCBI, PUBMED, EMBASE, Wangfang databases, and Web of Science databases were used to retrieve the available studies. MSG was linked with deleterious effects particularly in animals including induction of obesity, diabetes, hepatotoxic, neurotoxic and genotoxic effects showed in Literature. Few reports revealed increased hunger, food intake, and obesity in human subjects due to MSG consumption. Hepatotoxic, neurotoxic, and genotoxic effects of monosodium glutamate on humans carried out very limitedly. High consumption of monosodium glutamate may be linked with harmful health effects showed in available literatures. So, it is recommended to use common salt instead of MSG. Furthermore, intensive research is required to explore monosodium glutamate–related molecular and metabolic mechanisms. L-carnitine can protect from Hepatotoxic, neurotoxic, renal impairment and genotoxic effects functionally, biochemically and histopathologically with a corresponding reduction of oxidative stress.

POSSIBLE ROLE OF 5α-ANDROSTANE-3α,17β-DIOL IN THE CONTROL OF FOLLICLE-STIMULATING HORMONE SECRETION IN THE IMMATURE FEMALE RAT

1982 ◽  
Vol 92 (1) ◽  
pp. 37-42 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
P. KRAMER ◽  
L. GRIBLING-HEGGE
Keyword(s):  
Inhibitory Action ◽  
Combined Treatment ◽  
Hormone Secretion ◽  
Inhibitory Effect ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Immature Rat ◽  
Rat Strain ◽  
Intact Rats

A possible role of 5α-androstane-3α,17β-diol (3α-androstanediol) in the control of FSH secretion was studied at various ages in ovariectomized rats. In the rat strain used, vaginal opening, coincident with first ovulation, generally occurs between 37 and 42 days of age. If 3α-androstanediol alone was given as an ovarian substitute, an inhibitory effect on FSH release was evident with all three doses tested (50, 100, 300 μg/100 g body wt) between 13 and 30 days of age; at 33–35 days of age only the 300 μg dose caused some inhibition of FSH release. Results were more complex if 3α-androstanediol was given in combined treatment with oestradiol and progesterone. Given with progesterone, 3α-androstanediol showed a synergistic inhibitory action on FSH release between 20 and 30 days of age. However, when 3α-androstanediol was combined with oestradiol a clear decrease in effect, as compared to the effect of oestradiol alone, was found between 20 and 30 days of age. Also the effect of combined oestradiol and progesterone treatment was greater than the effect of combined treatment with oestradiol, progesterone and 3α-androstanediol. At all ages after day 20 none of the steroid combinations tested was capable of maintaining FSH levels in ovariectomized rats similar to those in intact rats. It is concluded that 3α-androstanediol might play a role in the control of FSH secretion in the immature rat, but after day 20 the potentially inhibitory action of 3α-androstanediol on FSH secretion is limited in the presence of oestradiol.

scholarly journals Antioxidants Promote Intestinal Tumor Progression in Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 241
Author(s):  
Zhiyuan V. Zou ◽  
Kristell Le Gal ◽  
Ahmed E. El Zowalaty ◽  
Lara E. Pehlivanoglu ◽  
Viktor Garellick ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Colorectal Cancer ◽  
Tumor Progression ◽  
Human Subjects ◽  
Plasma Concentrations ◽  
Intestinal Tumor ◽  
Adenomatous Polyposis ◽  
Intestinal Tumors ◽  
The Impact

Dietary antioxidants and supplements are widely used to protect against cancer, even though it is now clear that antioxidants can promote tumor progression by helping cancer cells to overcome barriers of oxidative stress. Although recent studies have, in great detail, explored the role of antioxidants in lung and skin tumors driven by RAS and RAF mutations, little is known about the impact of antioxidant supplementation on other cancers, including Wnt-driven tumors originating from the gut. Here, we show that supplementation with the antioxidants N-acetylcysteine (NAC) and vitamin E promotes intestinal tumor progression in the ApcMin mouse model for familial adenomatous polyposis, a hereditary form of colorectal cancer, driven by Wnt signaling. Both antioxidants increased tumor size in early neoplasias and tumor grades in more advanced lesions without any impact on tumor initiation. Importantly, NAC treatment accelerated tumor progression at plasma concentrations comparable to those obtained in human subjects after prescription doses of the drug. These results demonstrate that antioxidants play an important role in the progression of intestinal tumors, which may have implications for patients with or predisposed to colorectal cancer.

scholarly journals Learning Speech Production and Perception through Sensorimotor Interactions

2020 ◽  
Author(s):  
Shihab Shamma ◽  
Prachi Patel ◽  
Shoutik Mukherjee ◽  
Guilhem Marion ◽  
Bahar Khalighinejad ◽  
...  
Keyword(s):  
Vocal Tract ◽  
Human Subjects ◽  
Motor Task ◽  
Neural Processes ◽  
Mathematical Simulations ◽  
Predictive Role ◽  
Sensorimotor Interactions ◽  
Forward Projection ◽  
Cortical Regions

Abstract Action and Perception are closely linked in many behaviors necessitating a close coordination between sensory and motor neural processes so as to achieve a well-integrated smoothly evolving task performance. To investigate the detailed nature of these sensorimotor interactions, and their role in learning and executing the skilled motor task of speaking, we analyzed ECoG recordings of responses in the high-γ band (70 Hz-150 Hz) in human subjects while they listened to, spoke, or silently articulated speech. We found elaborate spectrotemporally-modulated neural activity projecting in both forward (motor-to-sensory) and inverse directions between the higher-auditory and motor cortical regions engaged during speaking. Furthermore, mathematical simulations demonstrate a key role for the forward projection in learning to control the vocal tract, beyond its commonly-postulated predictive role during execution. These results therefore offer a broader view of the functional role of the ubiquitous forward projection as an important ingredient in learning, rather than just control, of skilled sensorimotor tasks.

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