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421.
Jadwiga M. Giebultowicz Janet E. Joy John G. Riemann Ashok K. Raina 《Archives of insect biochemistry and physiology》1994,27(1):65-75
In the gypsy moth, Lymantria dispar, the release of sperm bundles from the testis into the upper vas deferens (UVD) is precisely timed within each 24 h period by a circadian mechanism located in the reproductive system. In males kept under light:dark cycles of 16:8, release of sperm bundles is limited to the 3 h period that starts before lights off. Sperm released from the testis remains in the UVD for about 12 h and then moves into the seminal vesicles, so that the UVD stays empty until the next cycle of sperm release begins. The rhythm of release appears to play a role in the terminal stages of sperm maturation and is essential for the fertility of males. Sperm bundles undergo substantial morphological changes during the release from the testis and while they are retained in the UVD. In this study, using gel electrophoresis, we compared protein patterns in sperm and in the UVD during the daily cycle of sperm release and maturation. Several protein bands evident in the sperm bundles contained in the testis were missing from the sperm bundles that had passed from the testis into the UVD. Furthermore, a number of new proteins appeared in the sperm bundles as they remained in the UVD. Some of these proteins appeared to be secreted from the UVD epithelium into the UVD lumen before being incorporated into sperm bundles. Correlations between changes in protein patterns and ultrastructural changes in sperm during the cycle of sperm release and maturation are discussed. © 1994 Wiley-Liss, Inc. 相似文献
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423.
In the general population, food constitutes the major environmental source of cadmium (Cd) in nonsmokers. It is established
that leafy vegetables, roots, and grains (wheat or rice) can accumulate relatively high amounts of Cd from the soil. Beef
liver and kidney and shellfish are also major dietary sources of Cd. The daily intake of Cd in various parts of the world
is different and depends on both the dietary habits and concentration of Cd in foodstuffs. Because of the long biological
half-life of Cd in humans and absence of any specific indicators of its toxicity, the environmental exposure of Cd should
be monitored in various countries. Although environmental Cd poisoning is rare, there are isolated reports on excessive exposure
to Cd in Japan and Shipham, a zinc-mining town in England. The body retention and toxicity of Cd depends on various factors,
such as daily intake, the form of Cd in food, its interactions with essential elements, and nutritional status of the population.
Since kidney is considered a critical organ in Cd toxicity, the indicators of renal dysfunction have been widely used for
evaluation of Cd poisoning in occupationally exposed people. It is unclear whether similar indicators can be used for monitoring
environmental Cd exposure. 相似文献
424.
Andrzej Płonka Diana Metodiewa Jadwiga Szymańska Andrzej elazowski 《Biochemical and biophysical research communications》1982,108(2):776-782
Radiolysis of aqueous solutions of renal and liver low molecular weight metal binding copper proteins was studied by the ESR method at low temperatures. Renal bismuth-copper chromochelatin and liver cadmium-zinc metallothionein like zinc-copper superoxide dismutase dismutate the superoxide radicals. Renal mercury-copper metallothionein traps effectively the hydroxyl radical. 相似文献
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427.
Abstract It was previously reported that spleen cells of rabbits infected with Treponema pallidum produced anti-treponemal lymphotoxins (ATL). This ability was distinctly disturbed when circulating immune complexes (CIC) and autolymphocytotoxins (AL) were present in the sera of cell donors. ATL liberated from cells of donors without CIC and AL displayed a marked ability to immobilize treponemes. The percentage of immobilized treponemes varied according to the type of cells used for ATL liberation and their density. The most active was ATL from T cells (density 4 × 108 ml−1 ) and the weakest was the one from B lymphocytes. In the presence of CIC in sera of cell donors the weakest ATL was from macrophages and in the presence of AL from T lymphocytes. When both factors (CIC and AL) were present ATL from T lymphocytes did not immobilize treponemes. This seems to suggest that the impairment of the cells' ability to produce ATL may facilitate the survival of treponemes in the host despite the presence of immunologically competent cells. 相似文献
428.
Porcine luteal cells were obtained from corpora lutea on the 5th, 13th and 17th days of the estrous cycle. The cells were suspended at a concentration of 5 × 104 cells/ml in Eagle's medium with 2% human serum albumin. These cells were incubated with or without 0.01, 0.1, 1 or 10 μg/ml porcine prolactin. The amount of progesterone in cultures was estimated by a radio-immunological method after 30 min, 3 h and 6 h of culturing.Luteal cells obtained on the 5th day of the estrous cycle and incubated without prolactin secreted 71.24 ± 21.91 ng progesterone/ml of medium, whereas under the influence of prolactin at 0.01, 0.1, 1 and 10 μg/ml, 39.06 ± 13.33, 44.31 ± 12.69, 44.88 ± 16.85 and 51.62 ± 15.01 ng progesterone/ml (P<0.01) were secreted. Luteal cells from the 13th day of the estrous cycle incubated without prolactin secreted on average 70.72 ± 9.21 ng progesterone/ml of medium, whereas under the influence of different prolactin doses 50.75 ± 8.52, 46.54 ± 7.13, 43.30 ± 6.78 and 41.68 ± 7.21 ng progesterone/ml (P<0.01) were secreted.Prolactin did not change progesterone secretion by luteal cells obtained on the 17th day of the estrous cycle. An influence of the incubation time on progesterone secretion by these cells was observed: after 30 min of incubation the cells secreted 8.83 ± 2.95 ng/ml, after 3 h 8.12 ± 2.57 ng/ml and after 6 h 6.86 ± 1.91 ng/ml, irrespective of the amount of PRL added.The results suggest that prolactin plays a role in the luteolysis of the corpus luteum. 相似文献
429.
Plich Jarosław Zimnoch-Guzowska Ewa Tatarowska Beata Śliwka Jadwiga 《Molecular biology reports》2020,47(3):1713-1722
Molecular Biology Reports - A conversion of amyloplasts into chloroplasts in the potato tuber after light exposure is known as tuber greening and is one of the major causes of tuber loss. We report... 相似文献
430.
Magdalena Wiecek Marcin Maciejczyk Jadwiga Szymura Malgorzata Kantorowicz Zbigniew Szygula 《Redox report : communications in free radical research》2017,22(6):367-376
Objectives: The aim of the study was to evaluate the activity of xanthine oxidase (XO) in the blood of men and women during the first hour following a single anaerobic exercise (AN-EX), and after 24 hours of recovery, and to determine whether the changes in XO activity in the blood after AN-EX are dependent on anaerobic performance.Methods: Ten men and ten women performed a single AN-EX. Blood was collected before and five times after completion of the AN-EX. The activity of XO was determined.Results: In both groups, a significant (P?0.05) increase in blood XO activity was found only 24 hours after the AN-EX. The increased activity of XO in men was significantly lower than in women (P?0.05). Negative correlations were found between the increase in XO activity in the blood plasma 24 hours after the AN-EX and anaerobic power, the total work performed during the AN-EX and the power decrease.Discussion: In the first hour after the single AN-EX, XO activity in the blood of women and men did not change, but after 24 hours of recovery, it was significantly higher compared to baseline levels in both sexes. Single AN-EX causes a smaller increase in XO activity in people with higher anaerobic performance. 相似文献