Estrogen deficiency is considered to be an important factor leading to cardiovascular diseases (CVDs). Indeed, the prevalence of CVDs in postmenopausal women exceeds that of premenopausal women and men of the same age. Recent research findings provide evidence that estrogen plays a pivotal role in the regulation of calcium homeostasis and therefore fine-tunes normal cardiomyocyte contraction and relaxation processes. Disruption of calcium homeostasis is closely associated with the pathological mechanism of CVDs. Thus, this paper maps out and summarizes the effects and mechanisms of estrogen on calcium handling proteins in cardiac myocytes, including L-type Ca2+ channel, the sarcoplasmic reticulum Ca2+ release channel named ryanodine receptor, sarco(endo)plasmic reticulum Ca2+-ATPase, and sodium-calcium exchanger. In so doing, we provide theoretical and experimental evidence for the successful design of estrogen-based prevention and treatment therapies for CVDs.

To investigate the effect of restricted grazing time on behavior of Tan sheep on desert steppe, forty 4-months old male Tan sheep with an original body weight (BW) of 15.62±0.33 kg were randomly allocated to 4 grazing groups which corresponded to 4 different restricted grazing time treatments of 2 h/d (G2), 4 h/d (G4), 8 h/d (G8) and 12 h/d (G12) access to pasture. The restricted grazing times had a significant impact on intake time, resting time, ruminating time, bite rate and movement. As the grazing time decreased, the proportion of time spent on intake, bite rate and grazing velocity significantly (p<0.05) increased, but resting and ruminating time clearly (p<0.05) decreased. The grazing months mainly depicted effect on intake time and grazing velocity. In conclusion, by varying their foraging behavior, Tan sheep could improve grazing efficiency to adapt well to the time-limited grazing circumstance.

The beneficial effects on meat quality of adding vitamin E to diets have been extensively studied in cattle and lamb. However, how supplemental vit E affects the performance and meat quality of ʽTanʼ sheep has not been reported. Thirtyfive male lambs of ʽTanʼ sheep (20-30 d after weaning) with similar body weight were randomly divided into five groups of seven each to receive a basal diet plus five levels of vit E supplementation: 0 (control group, CG), 20, 100, 200, and 2000 IU d -1 lamb -1 . The results showed: 1) no differences were observed in animal growth performance between CG and vit E treated groups (VG) (P > 0.05); 2) vit E supplementation levels over 200 IU d -1 lamb -1 dramatically suppressed subcutaneous fat deposition and similarly that above 100 IU d -1 lamb -1 considerably reduced drip loss and pH 24 h of Longissimus dorsi (LD) muscle in VG lambs compared to those of CG (P < 0.01), but with no significant effect on other carcass characteristics (P > 0.05); 3) although vit E supplementation generally did not affect the fatty acid composition of intramuscular lipids in LD muscle, the percentage of n-6 polyunsaturated fatty acids (PUFA) and the ratio of n-6/n-3 PUFA were significantly enhanced (P < 0.05) and an increasing tendency (P < 0.1) for both total PUFA proportion and the ratio of PUFA/saturated fatty acids (SFA) was also observed in ʽTanʼ sheep lambs treated with vit E. In conclusion, vit E supplementation of male ʽTanʼ sheep lambs did not influence growth performance, significantly reduced subcutaneous fat deposition, drip loss, pH 24 h and tended to improve fatty acid profile of LD muscle.

6‴-p-Coumaroylspinosin (P-CS), a bioactive flavonoid, is typically extracted from Semen Ziziphi Spinosae (SZS). In this study, a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed to determine P-CS for investigating the degradation characteristics of P-CS incubated with rat feces. The results showed that P-CS degraded rapidly and the degradation speeds varied depending upon the P-CS concentrations (3, 15, and 30 μg/mL). The degradation of P-CS processes follow first-order kinetics. On the basis of the mass spectrometry (MS) spectrum mode of the product ions, two main metabolites of P-CS were identified. Swertisin was the main metabolite at 3 and 15 μg/mL, while spinosin was produced when the P-CS concentration was 30 μg/mL. Spinosin and swertisin could improve mRNA transcription levels of glutamate receptor K1, K2, and K3 (GluK1, GluK2, and GluK3) subunits in rat hippocampal neurons. In addition, they showed an obvious synergistic effect in this respect. Collectively, the results can be used to explain the metabolic and pharmacological mechanisms of P-CS.

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