Effects of Chronic Stress and Phenytoin on the Long-term Potentiation （LTP） in Rat Hippocampal CA1 Region

Stress is the response to stimulation from inside andoutside with complicated effects on organisms. Appropri-ate stressful reactions are helpful in resisting diseases byactivating unspecific modulation system, while severe orprolonged stresses are harmful and even induce mentaland physical disorders such as recurrent depression, post-traumatic stress disorder (PTSD), Alzheimer’s disease andepilepsy [1]. Hippocampus, a main brain region of keyimportance for learning, memory and emotion, is t…     

Effects of Electro-Acupuncture on Ovarian P450arom,P450c17α and mRNA Expression Induced by Letrozole in PCOS Rats

Hyperandrogenism is a core factor in the series of reproductive and endocrine metabolic disorders involved in polycystic ovary syndrome (PCOS). Abnormalities in enzymatic activity and the expression of ovarian granular cell layer P450arom and theca cell P450c17α can lead to an atypical environment of local ovarian hormones, including excessive androgen levels. Rat models prepared with letrozole exhibit similar endocrine and histological changes to those that occur in human PCOS. We used such a model to study the role of electro-acupuncture (EA) in regulating ovarian P450arom and P450c17α enzymatic activity and mRNA expression in PCOS rats. Female Sprague Dawley (SD) rats aged 42 days were randomly divided into 3 groups (control, PCOS, and PCOS EA) consisting of 10 rats each. The PCOS and PCOS EA groups were administered a gavage of 1.0 mg/kg⁻¹ of letrozole solution once daily for 21 consecutive days. Beginning in the ninth week, the PCOS EA group was administered low-frequency EA treatment daily for 14 consecutive days. After the treatment, we obtained the following results. The estrous cycles were restored in 8 of the 10 rats in the PCOS EA group, and their ovarian morphologies and ultrastructures normalized. The peripheral blood measurements (with ELISA) showed significantly decreased androgens (i.e., androstenedione and testosterone) with significantly increased estrogens (i.e., estrone, estradiol) and increased P450arom with decreased P450C17α. Immunohistochemistry and Western blotting methods showed enhanced expression of ovarian granular cell layer P450arom as well as decreased expression of theca cell layer P450C17α. Fluorescence quantitative PCR methods showed enhanced expression of ovarian granular cell layer P450arom mRNA as well as decreased expression of theca cell layer P450C17α mRNA. These results may help explain the effects of electro-acupuncture in changing the local ovarian hyperandrogenic environment and improving reproductive and endocrine metabolic disorders in PCOS.     

Effects of starvation on the vitellogenesis,ovarian development and fecundity in the ectoparasitoid,Nasonia vitripennis （Hymenoptera： Pteromalidae）

A female-specific protein, vitellogenin （Vg）, and its corresponding egg vitellin （Vt） are identified in the ectoparasitic wasp Nasonia vitripennis. Both native Vt and Vg have a molecular mass of about 350 kDa, which is composed of two subunits of approximately 190 kDa and 165 kDa under reducing and denaturing conditions （sodium dodecyl sulfate-polyacrylamide gel electrophoresis）. An indirect sandwich enzyme-linked immunosorbent assay developed with both monoclonal and polyclonal antibodies against N. vitripennis Vt. Vg was first detected in the hemolymph on the 10th day after parasitism, and was first observed in oocytes on the 12th day. In adults deprived of food, the highest hemolymph Vg level occurred at the time of adult eclosion and the highest level of Vt in ovaries was found at 30 h after eclosion. In contrast, feeding adults with 20% sucrose resulted in the reduction of Vt uptake by ovaries and the extension of life span, but had little effect on Vg production. Deprived of hosts, starvation of female wasps had no significant effects on ovariole growth and oocyte maturation before the wasps died. However, starvation of female wasps supplied with hosts accelerated the wasps laying progeny into hosts, but resulted in a decrease of total progeny production by comparison with wasps fed with 20% sucrose.