In the present experiment, effects of sodium hydrosulfide (NaHS), a H2S donor, on the oxidative damage, antioxidant capacity and the growth of cucumber hypocotyls and radicles were studied under 100 mmol L-1 NaCl stress. NaCl treatment significantly induced accumulation of H2O2 and thiobarbituric acid-reactive substances (TBARS) in cucumber hypocotyls and radicles, and application of NaHS dramatically reduced the accumulation of H2O2 and lipid peroxidation. However, the alleviating effects greatly depended on the concentrations of NaHS, and 400 μmol L-1 NaHS treatment showed the most significant effects. Corresponding to the change of lipid peroxidation, higher activities of antioxidant enzymes as well as the antioxidant capacity indicated as DPPH scavenging activity, chelating activity of ferrous ions and hydroxyl radical (·OH) scavenging activity were induced by NaHS treatment under NaCl stress, especially by 400 μmol L-1 NaHS treatment. With the alleviating lipid peroxidation, the amylase activities in cotyledons were increased, and the length of cucumber hypocotyls and radicles were significantly promoted by NaHS treatment under NaCl stress. Unlike the effects of NaHS, pretreatment with other sodium salts including Na2S, Na2SO4, NaHSO4, Na2SO3, NaHSO3 and NaAc did not show significant effects on the growth of cucumber hypocotyls and radicles. These salts do not release H2S. Based on above results, it can be concluded that the effects of NaHS in the experiment depended on the H2S rather than other compounds derived from NaHS, and the alleviating effects might related with its function in modulating antioxidant capacity and amylase activities.

The objective of the study is to investigate the effects of active immunization against gonadotropin releasing hormone agonist (GnRH-A) on secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the pituitary, and to observe the histological structures and development about ovaries and uteri in female rabbits. 24 female rabbits (Oryctolagus cuniculus) were divided randomly into 4 groups (n=6), namely, experimental group I (EG-I), experimental II (EG-II), experimental III (EG-III), and control group (CG). Rabbits were subcutaneously injected with 1.0 mL GnRH-A (alarelin) antigen respectively at concentrations of 100, 100 and 50 μg mL-1 respectively, in EG-I, EG-II and EG-III. Alarelin antigen was re-injected in EG-II and EG-III with the same dosage on 20 d. CG was a blank. The ovarian and uterine samples were collected aseptically at the end of the experiment of 70 d. The tissue slices were observed under light and electron microscopes. Serum concentrations of LH and FSH were measured with ELISA. The results showed that serum LH concentrations in EG-II and EG-III reached the peak levels on 50 and 40 d respectively, and LH level in EG-II exceeded other 3 groups on 50 d (P<0.05). FSH level in EG-II was higher than those in EG-I, CG (P<0.01) and EG-III (P<0.05) on 40 d. GnRHA could increase the number of primary follicles, enlarge the primary follicle vertical diameter (PFV) and primary follicle transverse diameter (PFT), and promote growth and maturation of follicles. The endometrial epithelium thickness (EET) and uterine wall thickness (UWT) in three EGs were less than that in CG (P<0.05). GnRH-A can increase the quantities of mitochondrial cristaes, cortex granules in cytoplasm, broaden and lengthen zona pellucidas and microvilli of oocytes. It also enlarged nuclei of ooxytes and mitochondria, thereby it promoted the development of oocytes. Re-injection of 100 μg alarelin antigen enhanced the secretion of LH and FSH. GnRH-A promoted the growth and maturation of ovaries and follicles, suppressed uterine development, and also influenced histostructure of ovaries and uteri in female rabbits.