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Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
Institute of Health Sciences, China Medical University, Shenyang, Liaoning, China
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quantities of caffeine and phenolic substances, with arabica having relatively fewer of these compounds but higher levels of sucrose and diterpenoids ( Monteiro & Farah 2012 ). Arabica coffee is widely considered to be higher quality than robusta, which
School of Pharmaceutical Sciences and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming, China
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Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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Introduction Caffeine is a xanthine alkaloid that is widely present in coffee, tea, soft drink beverages, food and some analgesic drugs, making it one of the most frequently ingested psychoactive substances worldwide ( Brent et al. 2011
Basic Medical College of Nanyang Medical University, Nanyang, China
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Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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Introduction Caffeine, which is a common component of foods, beverages and pharmaceuticals, is widely ingested by people, even pregnant women ( Fredholm et al. 1999 , Kluger 2004 ). Approximately 75% of women consume caffeine during
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ABSTRACT
It was demonstrated that the altered endocrine environment caused by caffeine consumption could be equated with a stress-like pattern of response. A single acute treatment with caffeine (30 or 60 mg/kg) to male rats approximately 85 days old caused plasma concentrations of corticosterone, progesterone, testosterone and Na+ to rise significantly above control values. These changes were evident 3 min after caffeine administration and were maintained for 1–4 h before returning to normal. In animals exposed to daily chronic caffeine treatment for 10 days or more the levels of progesterone fell and Na+ rose significantly compared with control values at 24 h after administration. Following a single treatment of 30 mg/kg, caffeine was detected in blood plasma after 3 min, and reached peak levels by 1 h. After 24 h, less than 2% of the peak levels of caffeine remained. Metabolites of caffeine were detectable within 6 min and reached their peak levels 4 and 12 h later for theophylline and theobromine respectively.
It is suggested that high steroid levels may in the long-term cause an altered hepatic clearance pattern affecting both steroid metabolism and caffeine elimination. A preliminary study of the morphology of livers from males chronically exposed to caffeine revealed that the hepatic cells lost cytoplasmic matrix, and that the sinusoids did not show up as clear spaces, compared with those in the controls.
J. Endocr. (1988) 119, 275–280
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ABSTRACT
Intraperitoneal injection of caffeine (12·5–100 mg/kg) into rats caused a significant, dose-related increase in plasma corticosterone 2 h later, when the greatest response was measured. The corticosterone response to laparotomy stress or i.v. injection of ACTH(1–24) was unaffected by prior injection of caffeine. The response to stress or caffeine was unaffected by adrenal enucleation 28 days previously.
In vitro, 10 mmol caffeine/l stimulated basal release of corticosterone from adrenal quarters and potentiated the response to a sub-maximal stimulatory concentration of cyclic AMP (cAMP). The drug had no effect on release stimulated by a sub-maximal concentration of ACTH(1–24).
Release of ACTH from pituitary fragments incubated in vitro was stimulated in a dose-related manner by caffeine (0·01–10 mmol/l), and the responses to hypothalamic extract and sub-maximal concentrations of corticotrophin-releasing factor (CRF-41) or arginine vasopressin (AVP), but not cAMP, were significantly enhanced by 10 mmol caffeine/l.
Release of immunoreactive CRF-41 (but not AVP) was significantly increased by caffeine (0·01–10 mmol/l) added to hypothalami incubated in vitro. The response to injection of caffeine in vivo was completely prevented by pharmacological blockade of endogenous CRF release.
Taken together, these results show that caffeine at high concentrations can stimulate directly the release of the hormones of the hypothalamo-pituitary-adrenocortical axis in vitro, but the fact that these concentrations are unlikely to be reached after administration in vivo suggests that the effect of caffeine may be mediated centrally.
Journal of Endocrinology (1989) 122, 535–543
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unknown in most species. Caffeine and heparin have been widely used as suitable alternatives to improve the success rate of IVF ( Parrish et al. 1986 , Niwa & Ohgoda 1988 , Yoshida et al. 1990 ). It has been reported that ANP is synthesized in the
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DEX both in vivo and in vitro , cytosolic Ca 2 + dynamics were monitored in NRVM cultured in the presence or absence of DEX. After 24 h of DEX treatment, the NRVM were loaded with Fluo-3AM, and both spontaneous and caffeine-induced Ca 2 + release
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Department of Obstetrics and Gynecology, First Hospital of Soochow University, Suzhou, Jiangsu, China
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/L) ( Xiao et al. 2008 , Wu et al. 2014 ). Phenylephrine (PhE, 10 −9 –10 −4 mol/L), Bay K8644 (10 −11 –10 −5 mol/L), or caffeine (0.01 mol/L) was applied to the MCA for measuring vascular tension. All the drugs were diluted with HEPES-PSS solution
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SUMMARY
Ethacrynic acid inhibited short-circuit current (SCC, Na transport) across the toad bladder. Some structural analogues had similar effects and their potency varied with their ability to combine with SH groups. The Na-K ATPase inhibitor ouabain was more effective than ethacrynic acid and its action and that of ethacrynic acid was additive.
The natriferic and hydro-osmotic effects of vasopressin were inhibited by ethacrynic acid (10−5 and 10−4 m); the antagonism was competitive at 10− and 10−4 m (but not at 10−3 m). Certain analogues of ethacrynic acid also exhibited this effect but it was not clearly related to their SH-combining ability.
The natriferic and hydro-osmotic effects of caffeine and cyclic AMP were not changed by 10−4 m-ethacrynic acid.
Ethacrynic acid (10−4 m), which does not affect basal sodium transport in bladders pretreated for studying the action of aldosterone, prevented the initiation of the increase in sodium transport by aldosterone but was without effect when added to a toad bladder already under the influence of aldosterone. This suggests that ethacrynic acid interferes with metabolic processes underlying the action of aldosterone. Dihydroethacrynic acid which has no SH-binding activity was without effect.
Nottingham Digestive Disease Centre and Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
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similar effects in increasing BAT-dependent energy expenditure as does cold exposure ( Luo et al. 2012 ). Caffeine (1,3,7-trimethylxantine), a widely consumed plant alkaloid found in coffee, and tea has been shown to aid weight loss and increased energy
