Search Results

You are looking at 1 - 10 of 274 items for :

  • circadian rhythm x
  • Refine by access: All content x
Clear All
Michael Hastings Division of Neurobiology, MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK

Search for other papers by Michael Hastings in
Google Scholar
PubMed
Close
,
John S O’Neill Division of Neurobiology, MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK

Search for other papers by John S O’Neill in
Google Scholar
PubMed
Close
, and
Elizabeth S Maywood Division of Neurobiology, MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK

Search for other papers by Elizabeth S Maywood in
Google Scholar
PubMed
Close

rhythms, and then to apply this basic knowledge to understand what happens toour health and well-being when the body’s clockwork goes wrong. The suprachiasmatic nuclei(SCN)asa circadian clock It is perhaps unsurprising to observe

Free access
Taira Wada Laboratory of Health Science, School of Pharmacy, Nihon University, Funabshi, Chiba, Japan

Search for other papers by Taira Wada in
Google Scholar
PubMed
Close
,
Yukiko Yamamoto Laboratory of Health Science, School of Pharmacy, Nihon University, Funabshi, Chiba, Japan

Search for other papers by Yukiko Yamamoto in
Google Scholar
PubMed
Close
,
Yukiko Takasugi Laboratory of Health Science, School of Pharmacy, Nihon University, Funabshi, Chiba, Japan

Search for other papers by Yukiko Takasugi in
Google Scholar
PubMed
Close
,
Hirotake Ishii Laboratory of Health Science, School of Pharmacy, Nihon University, Funabshi, Chiba, Japan

Search for other papers by Hirotake Ishii in
Google Scholar
PubMed
Close
,
Taketo Uchiyama Laboratory of Organic Chemistry, School of Pharmacy, Nihon University, Funabshi, Chiba, Japan

Search for other papers by Taketo Uchiyama in
Google Scholar
PubMed
Close
,
Kaori Saitoh Department of Psychiatry, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan

Search for other papers by Kaori Saitoh in
Google Scholar
PubMed
Close
,
Masahiro Suzuki Department of Psychiatry, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan

Search for other papers by Masahiro Suzuki in
Google Scholar
PubMed
Close
,
Makoto Uchiyama Department of Psychiatry, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
Tokyo Adachi Hospital, Adachi, Tokyo, Japan

Search for other papers by Makoto Uchiyama in
Google Scholar
PubMed
Close
,
Hikari Yoshitane Department of Biological Sciences, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Search for other papers by Hikari Yoshitane in
Google Scholar
PubMed
Close
,
Yoshitaka Fukada Department of Biological Sciences, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Search for other papers by Yoshitaka Fukada in
Google Scholar
PubMed
Close
, and
Shigeki Shimba Laboratory of Health Science, School of Pharmacy, Nihon University, Funabshi, Chiba, Japan

Search for other papers by Shigeki Shimba in
Google Scholar
PubMed
Close

rhythm of behavior ( Moore & Eichler 1972 , Stephan & Zucker 1972 , Ralph et al. 1990 ). Peripheral tissues also have a circadian clock system, which can be driven autonomously ( Balsalobre et al. 1998 , Yamazaki et al. 2000 , Yoo et al. 2004

Open access
S A Cavigelli
Search for other papers by S A Cavigelli in
Google Scholar
PubMed
Close
,
S L Monfort
Search for other papers by S L Monfort in
Google Scholar
PubMed
Close
,
T K Whitney
Search for other papers by T K Whitney in
Google Scholar
PubMed
Close
,
Y S Mechref
Search for other papers by Y S Mechref in
Google Scholar
PubMed
Close
,
M Novotny
Search for other papers by M Novotny in
Google Scholar
PubMed
Close
, and
M K McClintock
Search for other papers by M K McClintock in
Google Scholar
PubMed
Close

circadian glucocorticoid rhythm is altered in several pathological states; e.g. major depressive disorder ( Sachar et al. 1973 , Linkowski et al. 1985 , Pfohl et al. 1985 ), Alzheimer’s disease, sleep deprivation ( Spiegel et al. 1999 ), and normal

Free access
Anjara Rabearivony School of Life Sciences and Technology, China Pharmaceutical University, Nanjing, China

Search for other papers by Anjara Rabearivony in
Google Scholar
PubMed
Close
,
Huan Li School of Life Sciences and Technology, China Pharmaceutical University, Nanjing, China

Search for other papers by Huan Li in
Google Scholar
PubMed
Close
,
Shiyao Zhang School of Life Sciences and Technology, China Pharmaceutical University, Nanjing, China

Search for other papers by Shiyao Zhang in
Google Scholar
PubMed
Close
,
Siyu Chen School of Life Sciences and Technology, China Pharmaceutical University, Nanjing, China

Search for other papers by Siyu Chen in
Google Scholar
PubMed
Close
,
Xiaofei An Department of Endocrinology, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China

Search for other papers by Xiaofei An in
Google Scholar
PubMed
Close
, and
Chang Liu School of Life Sciences and Technology, China Pharmaceutical University, Nanjing, China

Search for other papers by Chang Liu in
Google Scholar
PubMed
Close

timing signals for living organisms on Earth. Consequently, according to these signals, the endogenous circadian rhythms within organisms are entrained to the solar day ( Pittendrich 1960 , Refinetti 2010 , Fonken et al. 2013 ). While the central

Free access
Silvia Begliuomini
Search for other papers by Silvia Begliuomini in
Google Scholar
PubMed
Close
,
Elena Lenzi
Search for other papers by Elena Lenzi in
Google Scholar
PubMed
Close
,
Filippo Ninni
Search for other papers by Filippo Ninni in
Google Scholar
PubMed
Close
,
Elena Casarosa
Search for other papers by Elena Casarosa in
Google Scholar
PubMed
Close
,
Sara Merlini
Search for other papers by Sara Merlini in
Google Scholar
PubMed
Close
,
Nicola Pluchino
Search for other papers by Nicola Pluchino in
Google Scholar
PubMed
Close
,
Valeria Valentino
Search for other papers by Valeria Valentino in
Google Scholar
PubMed
Close
,
Stefano Luisi Division of Gynecology and Obstetrics, Division of Obstetrics and Gynecology, Department of Reproductive Medicine and Child Development, University of Pisa, Pisa 56100, Italy

Search for other papers by Stefano Luisi in
Google Scholar
PubMed
Close
,
Michele Luisi
Search for other papers by Michele Luisi in
Google Scholar
PubMed
Close
, and
Andrea R Genazzani
Search for other papers by Andrea R Genazzani in
Google Scholar
PubMed
Close

there are no studies at present in the literature investigating a possible BDNF circadian rhythm in humans, we studied the BDNF levels throughout 24 h in healthy men, in order to detect the possible relative changes in plasma BDNF protein. Additionally

Free access
D. C. HOLLEY
Search for other papers by D. C. HOLLEY in
Google Scholar
PubMed
Close
,
D. A. BECKMAN
Search for other papers by D. A. BECKMAN in
Google Scholar
PubMed
Close
, and
J. W. EVANS
Search for other papers by J. W. EVANS in
Google Scholar
PubMed
Close

Department of Animal Science, University of California, Davis, California 95616, U.S.A.

(Received 8 October 1974)

Few studies have dealt with diurnal cortisol rhythm in sheep (McNatty, Cashmore & Young, 1972; McNatty & Young, 1973). The present results elucidate further the circadian rhythm of ovine plasma cortisol and describe the effect of sudden and continuous cage restraint.

Experimental methods and conditions were reported in detail by Holley & Evans (1974). Six mature rams were sampled at 4 h intervals for 32 days. On day 17 the animals were placed singly in small cages. Throughout the experiment the sheep received lucerne pellets at 16.00 h and the lighting schedule was maintained at 14 h light: 10 h darkness. Plasma cortisol was determined in duplicate without correction for other steroids as described by Bassett & Hinks (1969) and adjusted for extraction efficiency.

Fig. 1. Daily percentage variations (means ± s.e.m.) in plasma cortisol

Restricted access
Y. C. PATEL
Search for other papers by Y. C. PATEL in
Google Scholar
PubMed
Close
,
H. W. G. BAKER
Search for other papers by H. W. G. BAKER in
Google Scholar
PubMed
Close
,
H. G. BURGER
Search for other papers by H. G. BURGER in
Google Scholar
PubMed
Close
,
M. W. JOHNS
Search for other papers by M. W. JOHNS in
Google Scholar
PubMed
Close
, and
JOANNE E. LEDINEK
Search for other papers by JOANNE E. LEDINEK in
Google Scholar
PubMed
Close

Pharmacological doses of glucocorticoids inhibit thyroid function in man and laboratory animals due to suppression of thyrotrophin (TSH) secretion (Wilber & Utiger, 1969). Administration of prednisolone or dexamethasone for 1–2 days results in a suppression of basal serum TSH levels in normal subjects and in patients with primary hypothyroidism, whilst the pituitary TSH reserve capacity, as assessed by the response to synthetic thyrotrophin releasing hormone (TRH), remains unaltered (Wilber & Utiger, 1969; Besser, Ratcliffe, Kilborn, Ormston & Hall, 1971; Haigler, Pittman & Hershman, 1971). However, impairment of serum TSH response to administered TRH does occur in patients treated with glucocorticoids for 1 or more months (Otsuki, Dakoda & Baba, 1973). These studies suggest that glucocorticoids may inhibit TSH secretion at both hypothalamic and pituitary levels but the main effect of the short-term treatment is suppression of TRH production.

Nicoloff, Fisher & Appleman (1970) found that the circadian rhythm of thyroidal

Restricted access
J. W. SACKMAN
Search for other papers by J. W. SACKMAN in
Google Scholar
PubMed
Close

SUMMARY

The uptake of radioactive phosphorus by the pineal gland in White Leghorn cockerels (Gallus domesticus) showed a diurnal variation with maxima in the light phase and minima in the dark phase of the light:dark cycle. Constant light caused the rhythm to disappear while constant dark had no effect other than lowering the amplitude of the variations. These data indicate that the rhythm in pineal uptake of 32P is circadian.

Restricted access
J. F. Cockrem
Search for other papers by J. F. Cockrem in
Google Scholar
PubMed
Close
and
B. K. Follett
Search for other papers by B. K. Follett in
Google Scholar
PubMed
Close

ABSTRACT

Melatonin was measured by radioimmunoassay in homogenates of pineal glands from quail (Coturnix coturnix japonica) kept under different photoperiods and in darkness. Under 8-, 12- and 16-h daylengths melatonin levels were increased during the dark period, the duration of the increase depending on the duration of the dark period. As the daylength was increased the peak occurred closer to lights-off, reflecting the more rapid melatonin rise under the longer photoperiods. The pineal melatonin rhythm continued in darkness with an amplitude relative to that seen under a light/dark cycle of slightly less than one-half after 2 days in darkness and one-third after 6 days in darkness. The corresponding average periods of the rhythm were 25·5 h and 25·7 h. These results show that there is a circadian rhythm of melatonin in the pineal gland of the quail which is entrained by light/dark cycles and which continues in darkness.

J. Endocr. (1985) 107, 317–324

Restricted access
Roberto Dominguez
Search for other papers by Roberto Dominguez in
Google Scholar
PubMed
Close
,
Laura Riboni
Search for other papers by Laura Riboni in
Google Scholar
PubMed
Close
,
Domingo Zipitria
Search for other papers by Domingo Zipitria in
Google Scholar
PubMed
Close
, and
Rodolfo Revilla
Search for other papers by Rodolfo Revilla in
Google Scholar
PubMed
Close

Rats with a 4-day oestrous cycle were given a single dose of atropine (100, 300, 500 or 700 mg/kg body wt) at 13.00 h on the days of oestrus, dioestrus 1, dioestrus 2 or pro-oestrus and were autopsied on the next expected day of oestrus. The doses of atropine (in mg/kg body wt) necessary to block ovulation during the cycle were 300 at oestrus, 100 at dioestrus 1 or 2 and 700 at pro-oestrus. A single dose of atropine (100 mg/kg) at oestrus, dioestrus 1 or dioestrus 2 was given at 09.00, 13.00, 17.00 or 21.00 h, autopsy again being performed on the next expected day of oestrus. The ability of atropine to block ovulation appeared to have a circadian rhythm, with a maximum blockade at 13.00 h on dioestrus 1 and dioestrus 2 and a minimum at 21.00 h on the same days. Hormone replacement (human chorionic gonadotrophin at oestrus, dioestrus 1 or 2, oestradiol benzoate at dioestrus 2 or progesterone at pro-oestrus) re-established normal ovulation in rats whose ovulation was blocked with atropine (100 mg/kg) on dioestrus 1 at 13.00 h. When ovulation was blocked with atropine but no hormone replacement had been given, rats ovulated 24 h after the next expected day of oestrus.

Results obtained in these experiments suggest the existence of a circadian rhythm of gonadotrophin secretion thoughout the oestrous cycle and a close relationship between that rhythm and the cholinergic system.

Restricted access