首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The acid phosphatase is studied in the prostate gland of rats. It is shown that 10 days after gonadectomy the activity of acid phosphatase lowered considerably. Administration of testosterone propionate or 5 alpha-dihydrotestosterone to castrated animals restored the enzyme activity whereas 5 alpha-androstan-3 beta,17-diol was not effective. Administration of testosterone propionate with one of its metabolites increased the activity of acid phosphatase in the prostate gland, however to a less extent than with the use of the hormone itself. The lowest activity is detected with the simultaneous application of three androgens.  相似文献   

2.
The presence of alkaline phosphatase (EC 3.1.3.1) activity has been demonstrated in nuclei of rat ventral prostate. This enzyme activity remained after washing of isolated nuclei with 0.5% Triton X-100; an acid phosphatase initially present with the nuclear fraction was removed by this treatment. The nuclear alkaline phosphatase, examined by utilizing p-nitrophenyl phosphate as substrate, had a pH optimum of 9.5-10.3, and a broad substrate specificity: p-nitrophenyl phosphate greater than phosphothreonine greater than beta-glycerophosphate greater than phosphoserine. The nuclear phosphatase was sensitive to denaturation by heat or urea treatments and was also inhibited by Pi, L-phenylalanine, homoarginine, dithiothreitol, and EDTA. The EDTA-inhibited enzyme was maximally reactivated by Zn2+, although Mg2+, or Ca2+ were also effective at somewhat higher concentrations. Orchiectomy of adult rats resulted in an increase in the nuclear alkaline phosphatase activity (2-3-fold at 24 or 48 h postorchiectomy). A decline in the protein: DNA ratio also occurred following orchiectomy, but the increase in phosphatase specific activity was evident whether expressed per unit of protein or per unit of DNA. Testosterone replacement following orchiectomy abolished the increase in nuclear phosphatase activity. The results suggest that the prostatic nuclear alkaline phosphatase may be involved in events related to inactivation of the prostate nucleus following androgen deprivation.  相似文献   

3.
We have studied several parameters of prostate function in two inbred lines (2.4 and SsLak) of young and old LSH hamsters. These included weight, acid phosphatase, and [3H]testosterone uptake as influenced by age, castration, and androgen treatment. In the hamster, prostatic acid phosphatase concentration was found to vary inversely with androgen levels, contrary to the usual assumption that this enzyme is androgen dependent. Prostatic uptake of tritiated testosterone was enhanced by castration and by treatment of castrates with doses of androgen which induced a moderate increase in gland size. With advancing age, the prostates of LSH hamsters (both strains) became atrophic rather than hyperplastic, in contrast with a previous report (1). This atrophy appeared to be a consequence of decreased testicular function. The LSH hamsters appear to be a suitable model for the study of senescent changes in the male reproductive system.  相似文献   

4.
The prostate is present in both male and female mammals. It is composed of secretory epithelium, connective stroma, smooth muscle and neuroendocrine cells, which are under hormonal regulation. Acid phosphatases catalyze the hydrolysis of orthophosphate monoesters. We have compared the expression of acid phosphatases in gerbil (Meriones unguiculatus) prostate glands in both sexes using young, adult and old animals. Eighteen prostates were isolated, frozen, sectioned, fixed, incubated with sodium beta-glycerophosphate sodium, washed with acetate buffer solution, treated with ammonium sulfide and counterstained with Methyl-Green aqueous solution. Ultracytochemical analyses were also conducted. This substrate revealed total acid phosphatase activity. The expression of the enzyme was heterogeneous, occurring in all ages during postnatal development. The data revealed that the female prostate matured before the male prostate. In addition, acid phosphatase activity in both sexes was regulated by androgen variation concomitant with development.  相似文献   

5.
The effects of chronic exposure to cadmium (Cd) on some selected biochemical parameters, as well as the possible protective role of aqueous extracts of Hibiscus sabdariffa L petal were studied in 12-wk-old male Wistar albino rats. Exposure to Cd caused a significant increase in plasma l-alanine aminotransferases (ALT) only but with a corresponding decrease in liver l-alanine and l-aspartate aminotransferases (L-ALT, L-AST) when compared to the Cd-free control. Total superoxide dismutase activity was decreased in the liver, testis, and prostate of Cd-exposed rats, whereas malondialdehyde (MDA) concentrations were increased relative to the Cd-free control. The metal significantly increased prostatic acid phosphatase activity in the prostate, but decreased the body weight gain of the rats and organ/body weight ratio for prostate and testis compared to the Cd-free control. Pretreatment of rats with aqueous extract of H. sabdariffa resulted in significantly less hepatotoxicity than with Cd alone as measured by plasma ALT and liver ALT and AST activities. The extract also protected the rats against Cd-induced liver, prostate, and testis lipoperoxidation as evidenced by significantly reduced MDA values in these organs, as well as reduced prostatic acid phosphatase activity in the prostate, when compared to the Cd-only exposed rats. Also, when compared to the organ/body weight ratios obtained from rats exposed to Cd alone the prostate and testis were protected by the extract as shown by enhanced prostate/body weight and testis/body weight ratios of Cd- and extract-treated rats. These data suggest that H. sabdarrifa L might be protective in Cd toxicity.  相似文献   

6.
Most of the biological processes in the living organisms of both animals and man are known to be of rhythmical nature. Variability of enzymatic activity in circadian cycle depends on many factors among other on age, sexual maturity, diet as well as medication. The results obtained in our studies indicate, that the activity changes of acid phosphatase and ATP-ase Mg++ dependent in the liver of all the examined age groups were of 24 hour circadian rythm. As to the acid phosphatase activity the results of this experiments showed that in circadian cycle in all examined age groups there is only one peak of elevated activity. ATP-ase Mg++ dependent showed two activity peaks appearing at the same hour both in 30 and 60 days old animals. It should be noticed that the activities of ATP-ase Mg++ dependent in 100 day old animals were two times higher than in 30 and 60 days old rats.  相似文献   

7.
不同磷源对红三叶草根际和菌根际磷酸酶活性的影响   总被引:17,自引:2,他引:15  
以红三叶草为研究对象,利用三室培养系统,在接种菌根真菌(Glomus mosseae)的条件下研究了不同磷源对根际和菌根际磷酸酶活性的影响,植株生长8周后收获并测定根室、菌丝室的土壤磷酸酶活性、植株干重及含磷量.结果表明,根室酸性磷酸酶活性比碱性磷酸酶活性更裔,接种条件下二者都稍有增加,特别是在供给有机磷(植酸钠)的条件下明显增加了菌丝室土壤磷酸酶活性.接种菌根真菌显著增加了植株干重、磷含量和总磷吸收.施用磷酸二氢钾(KH2PO4)时菌丝吸磷量占吸磷总量的43.1%,而施用植酸钠(Na-phytate)时菌丝吸磷量占吸磷总量的60.8%。  相似文献   

8.
Intestinal absorption of most nutrients is enhanced in diabetic rats. We wished to test the hypothesis that manipulation of dietary fatty acids will modify enhanced uptake of glucose in rats with established streptozotocin-diabetes. Chow-fed control rats or animals with one week of streptozotocin-diabetes were continued on chow or were fed ad libitum for three weeks with semisynthetic isocaloric diets containing a high content of either essential polyunsaturated or non-essential saturated fatty acids. The jejunal and ileal in vitro uptake of varying concentrations of glucose was much higher in diabetic than control rats fed chow or the saturated fatty acid diet. In contrast, the enhanced uptake of this sugar was reduced or normalized in diabetic rats fed the polyunsaturated fatty acid diet. Feeding the polyunsaturated fatty acid diet was associated with increased brush-border membrane activity of alkaline phosphatase in diabetic jejunum and ileum, but neither the saturated fatty acid diet nor the polyunsaturated fatty acid diet altered brush-border membrane cholesterol or phospholipids in control or in diabetic rats. Mucosal surface area was similar in diabetic rats fed the saturated fatty acid diet or the polyunsaturated fatty acid diet. Thus, (1) feeding the polyunsaturated fatty acid diet diminishes the enhanced jejunal and ileal uptake of glucose in diabetic rats, and (2) the influence of the polyunsaturated fatty acid diet on uptake in diabetic rats was not explained by alterations in intestinal morphology or brush-border membrane content of cholesterol or phospholipids. This study suggests that manipulation of dietary lipids may play a role in the normalization of the enhanced intestinal glucose uptake in rats with established diabetes.  相似文献   

9.
Human prostate acid phosphatase (EC 3.1.3.2) has been shown to dephosphorylate different phosphoproteins with the maximum rate at pH 4.0-4.5. The activity with phosvitin is distinctly higher than with beta-casein, casein and most of all than with riboflavin-binding protein. The native phosvitin is homogeneous on isoelectric focusing with pI value of 2.1, whereas phosvitin partially dephosphorylated (in about 15%) by the prostate acid phosphatase shows multiple bands with pI values of 3.5 - 6.8 or higher. The phosphate groups bound to serine residues are removed enzymatically twice as fast as phosphothreonine residues. The apparent Km value for phosvitin was 2.4 X 10(-7) M, and is by three orders of magnitude lower than Km of p-nitrophenyl phosphate (2.9 X 10(-4) M). The competitive inhibitors of prostate acid phosphatase, fluoride and L(+)-tartrate, show the same Ki values for phosvitin and p-nitrophenyl phosphate.  相似文献   

10.
6-Methylene progesterone (6MP) is an irreversible in vitro kcat inhibitor of rat prostate 5 alpha-reductase, the enzyme which converts testosterone (T) to dihydrotestosterone (DHT). Treatment of adult rats with 6MP or diethylstilbestrol (DES) decreased the weight of the ventral prostate (VP) by 45%, while castration reduced it by 86%. Histologically, the 6MP-treated VP were indistinguishable from those of controls, while the VP from DES-treated rats showed fibrous stromal hypertrophy as in castrated rats. The prostatic hydroxyproline content, an index of collagen levels, was enhanced by castration or DES, but was not significantly increased by 6MP. Within 2 days of 6MP treatment, the 5 alpha-reductase activity was reduced by 46% and ornithine decarboxylase (ODC) activity was lowered by 27%. During this time the prostatic acid phosphatase activity increased 42% and remained elevated with continued exposure to 6MP up to 13 days. The castration-induced involution of the VP was accompanied by a reduction in serum T and an increase in serum luteinizing hormone (LH). 6MP had no effect on T and LH serum levels but reduced the DHT content within the VP by 64%. Our results indicate that the structure and secretory acid phosphatase activity of the VP are less sensitive to changes in the ratio of T:DHT than is cell proliferation. Thus, the relative amounts of DHT and T within the VP may prove to be more significant than the absolute amount of either androgen in controlling prostate growth or its attendant neoplasms.  相似文献   

11.
Although fasting and refeeding reveal the existence of age-related changes in carbohydrate and lipid metabolism, the effects of aging on mineral metabolism in refed animals are unknown. We therefore investigated hormonal regulation of calcium metabolism in young (4 months) and old (26 months) male rats fasted for 48 hours and then refed for 4 or 24 hours. Serum concentrations of total and ionized calcium and parathormone were similar in control young and old rats. Serum calcitonin level was higher, and the concentrations of albumin and inorganic phosphate and alkaline phosphatase activity were lower in fed old rats. In young fasted rats, the serum ionized and total calcium was decreased, and phosphate concentration was increased. In old rats, fasting resulted in the increase of serum parathormone level. Fasting reduced serum alkaline phosphatase activity to a similar extent in both age groups. In young rats, refeeding for 24h normalized serum calcium and phosphate levels and alkaline phosphatase activity, and decreased serum concentrations of PTH and calcitonin. In old refed rats, serum calcitonin concentration was raised by 77% compared to fed or fasted animals, whereas parathormone levels were normalized. Our results indicate that old fasted or refed rats maintain normal serum calcium concentration in a different way than young animals, possibly through the increase in serum levels of parathormone and/or calcitonin. Thus, dietary manipulations such as fasting and refeeding constitute an interesting model for the investigation of the effects of aging on the hormonal regulation of serum calcium level.  相似文献   

12.
Daily treatment with 5 or 500 mug of estradiol benzoate of male adult rats for 7 days did not change the activity of testosterone 5alpha-reductase in the ventral prostate, while the activity decreased slightly in the dorsolateral prostate. The activity of alkaline phosphatase was increased by 60% over the respective control in the ventral prostate from rats treated with the larger dose of estrogen, but the estrogen treatment did not affect the alkaline phosphatase activity in the dorsolateral prostate. On the contrary, the estrogen treatment evoked three-fold elevation in the arginase activity of the dorsolateral prostate in contrast to the decreased arginase activity in the ventral prostate following estrogen administration. From these results, it was concluded that the alterations in some enzyme activity of the ventral and the dorsolateral prostates evoked by estrogen treatment were different from those observed in the respective lobes from castrated animals, although both estrogen administration and castration induced atrophy of the tissue. Furthermore, it might be also worth-while to mention that the ventral and the dorsolateral prostates of rats responded in a different manner to estrogen administered.  相似文献   

13.
The influence of training on fatty acid and glyceride synthesis by liver and adipose tissue homogenates of young and old Fischer-344 rats was examined. Four groups of rats (10 animals/group) were studied: young untrained, young trained, old untrained, and old trained. Training of each group was for 10 wk at 75% maximal O2 uptake. Young rats were killed at 6 mo of age and old rats were killed at 27 mo of age. Fatty acid synthesis was assessed by measuring the activities of acetyl-CoA carboxylase, fatty acid synthase, ATP citrate-lyase, "malic" enzyme, and glucose-6-phosphate dehydrogenase. Glyceride synthesis was evaluated by determining the rate of incorporation of [14C]glycerol 3-phosphate into lipids. In addition, lipoprotein lipase activity was measured in acetone-ether powders of adipose tissue from the four groups of rats. In liver, training had no effect on fatty acid or glyceride synthesis in either group. However, aging caused a significant decrease in the activities of four of the lipogenic enzymes but had no effect on glyceride synthesis. Training caused an increase in fatty acid synthase and glyceride synthesis in adipose tissue, and aging decreased lipoprotein lipase activity. It was concluded that training enhances the synthetic capacity of lipids by adipose tissue but that aging had a more profound effect in that the activities of the enzymes involved in these processes were lower in the old rats. Furthermore, the decreased activity of lipoprotein lipase in the older rats may explain the higher plasma triglyceride levels that were observed in these animals.  相似文献   

14.
Immunocytochemical characterization of several epithelial markers using the PAP technique was analyzed during different stages of induced prostatic hyperplasia in rats. Intact adolescent rats (42 days old) were treated with citral (3,7 dimethyl-2,6 octadienal) for 10, 30 and 100 days and their ventral prostate compared to untreated, matched-age animals. Among the epithelial markers studied the prostatic specific acid phosphatase was present in hyperplastic prostates of rats. The immunoreaction showed a fair correlation with the severity of lesion and duration of treatment. The prostatic specific antigen showed equally immunoreactive in both control and treated rats. The hyperplastic and normal rat prostates did not show immunoreactivity towards the other epithelial cell markers such as epithelial membrane antigen, carcinoembrionic antingen and alpha-fetoprotein antisera. It is concluded that prostatic specific acid phosphatase, and to a lesser extent prostatic specific antigen, might represent valuable markers for comparative studies of prostatic hyperplasia in rodents.  相似文献   

15.
Liu W  Zhang XM  Wang LB 《动物学研究》2010,31(6):627-632
采用动物性饵料和人工饲料培育1~10日龄怀头鲇(Silurus soldatovi)仔稚鱼,分析测定了全鱼酸性、碱性蛋白酶、淀粉酶、脂肪酶以及碱性磷酸酶的活性。结果表明:孵化后3天开口期仔鱼已具有较高的碱性蛋白酶活性,5日龄时碱性蛋白酶比活力达到较高值,8日龄时出现低值,总体变化呈波动上升趋势;酸性蛋白酶活性在1~8日龄处于较低水平,8日龄后开始迅速升高;淀粉酶活性在5日龄左右达到最高值,随后酶活性开始下降至较低水平;脂肪酶活性变化波动较大,表现为双峰型,两个峰值分别出现在3~4日龄和6~8日龄。摄食动物性饵料仔稚鱼消化酶活性和碱性磷酸酶活性均高于摄食人工饲料。在整个早期发育过程中,碱性蛋白酶比酸性蛋白酶活性高,碱性蛋白酶、淀粉酶比活力在约8日龄仔稚鱼转变期明显下降,而酸性蛋白酶活性开始迅速升高,这说明消化酶活性的变化与仔稚鱼发育过程中消化机能转换具有相关性。怀头鲇在10日龄内碱性磷酸酶活性呈上升趋势,表明怀头鲇胃肠道功能的逐步发育完善。  相似文献   

16.
The impact of phosphorus (P) availability on root proliferation, proton efflux, and acid phosphatase activities in roots and leaves was investigated in two lines of common bean (Phaseolus vulgaris): BAT 477 and CocoT. Phosphorus was supplied as KH2PO4 at 0 and 60 μmol per plant (0P and 60P, respectively). Under P shortage, the plant growth was more restricted in CocoT than in BAT 477, shoots being more affected than roots. The root area increased significantly at 0P in both lines. Up to 1 week following P shortage, the proton efflux increased in both lines despite a higher extent in BAT 477 as compared to CocoT. Root acid phosphatase activity was significantly higher under P limitation in the both lines, this trend being more pronounced in BAT 477 than in CocoT. This was also true for the leaf acid phosphatase. Regardless of the bean line, higher values were recorded for the old leaves as compared to the young ones for this parameter. Interestingly, a significant correlation between Pi content in old leaves and their acid phosphatase activity was found in P-lacking (0P) plants of the both bean lines, suggesting that acid phosphatase may contribute to increase the phosphorus use efficiency in bean through the P remobilization from the old leaves. As a whole, our results highlight the significance of the root H+ extrusion and the acid phosphatase activity rather than the root proliferation in the relative tolerance of BAT 477 to severe P deficiency.  相似文献   

17.
To elucidate the phenotypic expression of proliferating prostatic cells, rats were castrated, and the regenerating process of involuted ventral prostates during testosterone propionate (TP) administration was investigated by examining morphology, [5-125I]iododeoxyuridine (125I-UdR) uptake, DNA content, weight, acid phosphatase, and delta 4-steroid 5 alpha-reductase (5 alpha-reductase) activities. Morphologically, TP treatment initially increased the number of epithelial cells lining glandular lobules and subsequently restored the shape of epithelial cells. 125I-UdR uptake peaked on Day 3 of TP treatment and stayed at higher levels than for uncastrated controls until Day 14 of treatment. Prostatic weight, protein content, acid phosphatase, and DNA content returned to uncastrated control levels by Day 14 of TP treatment. TP administration markedly stimulated prostatic 5 alpha-reductase activity, which peaked on the Day 5 of treatment and decreased to uncastrated control levels by Day 14 of treatment. It is concluded that TP administration to castrated rats initially induced active mitotic division of the remaining stem cells, followed by formation of differentiated functional epithelial cells. Prostatic 5 alpha-reductase was highly active at the initial phase of active mitotic cell division. The major portion of the increased enzyme activity can be regarded as a phenotypic expression of stem or transient cells of prostatic epithelium.  相似文献   

18.
We have earlier shown that the renal dopaminergic system failed to respond to high salt (HS) intake in old (24-month-old) Fisher 344 rats (Hypertension 1999;34:666-672). In the present study, intestinal Na+,K+-ATPase activity and intestinal dopaminergic tonus were evaluated in adult and old Fischer 344 rats during normal salt (NS) and HS intake. Basal intestinal Na+,K+-ATPase activity (nmol Pi/mg protein/min) in adult rats (142+/-6) was higher than in old Fischer 344 rats (105+/-7). HS intake reduced intestinal Na+,K+-ATPase activity by 20% (P<0.05) in adult, but not in old rats. Dopamine (1 microM) failed to inhibit intestinal Na+,K+-ATPase activity in both adult and old Fischer 344 rats (NS and HS diets). In adult animals, co-incubation of pertussis toxin with dopamine (1 microM) produced a significant inhibitory effect in the intestinal Na+,K+-ATPase activity. L-DOPA and dopamine tissue levels in the intestinal mucosa of adult rats were higher (45+/-9 and 38+/-4 pmol/g) than those in old rats (27+/-9 and 14+/-1 pmol/g). HS diet did not change L-DOPA and DA levels in both adult and old rats. DA/L-DOPA tissue ratios, an indirect measure of dopamine synthesis, were higher in old (1.1+/-0.2) than in adult rats (0.6+/-0.1). Aromatic L-amino acid decarboxylase (AADC) activity in the intestinal mucosa of old rats was higher than in adult rats. HS diet increased the AADC activity in adult rats, but not in old rats. It is concluded that intestinal dopaminergic tonus in old Fisher 344 rats is higher than in adult rats and is accompanied by lower basal intestinal Na+,K+-ATPase activity. In old rats, HS diet failed to alter the intestinal dopaminergic tonus or Na+,K+-ATPase activity, whereas in adult rats increases in AADC activity were accompanied by decreases in Na+,K+-ATPase activity. The association between salt intake, increased dopamine formation and inhibition of Na+,K+-ATPase at the intestinal level was not as straightforward as that described in renal tissues.  相似文献   

19.
The concentration of dihydrotestosterone was measured by radioimmunoassay in nuclear and cytoplasmic extracts from rat ventral prostates. In the regenerating prostates of castrated rats treated with dihydrotestosterone for 4 days, the nuclear concentration of this steroid increased from approx. 70nM to 800nM as a linear function of the injected dose, whereas the cytoplasmic concentration remained relatively constant (70-130nM). Isotope-exchange measurements of nuclear androgen receptors by using [3H]methyltrienolone indicated that, although the concentration of nuclear dihydrotestosterone was several-fold higher than the concentration of androgen receptors, they were logarithmically related. The recruitment of prostatic cells into the growth fraction and the stimulation of 5 alpha-reductase activity were more directly correlated to the nuclear concentration of androgen receptors than to the total nuclear concentration of dihydrotestosterone. Maximal restoration of a specific isoenzyme of acid phosphatase ws achieved when approx. 2000 androgen receptors were present in the prostatic nuclei; higher concentrations of nuclear androgen receptors were associated with decreased amounts of this enzyme. Hence the results imply, first, that the total amount of dihydrotestosterone accumulated by nuclei is not a direct consequence of carrier-mediated transport by androgen receptors, and, secondly, that, whereas acid phosphatase may be differentially controlled by androgens in the regenerating prostate, increases in the amount of cell proliferation and 5 alpha-reductase activity directly parallel increases in the nuclear concentration of androgen receptors.  相似文献   

20.
The effects of cadmium chloride (Cd) alone (1 mg given as a single injection) or in combination with ascorbic acid (AA; 100 mg/day for 10 days) on the secretory functions of sex accessory glands of rats were studied in healthy male albino rats. Animals were sacrificed after 10 days treatment and the seminal vesicles (SVs), dorsolateral prostate (DLP), ventral prostate (VP), bulbourethral glands (BU), and coagulating glands (CO) were excised and weighed. Weight of all accessory glands were decreased by 10 days treatment with Cd. Cd + AA gave similar results. AA concentration increased in all glands and was significantly increases in CO (p less than .01). Levels of ascorbogin increased in all glands except CO and BU and in the latter a significant (p less than .001) increase was found. The rate of AA utilization increased significantly (p less that .001) in the accessories. A significant (p less than .001) reduction in the activity of succinate dehydrogenase was observed in Cd-treated rats with a further reduction with combined treatment. Alkaline phosphatase decreased (p less than .001) after Cd treatment but AA in combination restored it to control levels. Cd increased acid phosphatase (p less than .001) and was further activated by Cd + AA. Phosphorylase activity was elevated with Cd (p less than .001) but recovery occurred in SV and BU with Cd + AA. Glycogen increased (p less than .001; .01) with both treatments as did citric acid. Protein results were inconsistent with Cd but activation was found in most glands under combined treatment. The results reveal that most androgen-dependent biochemical constituents and organ weights were affected significantly by a single injection of Cd. AA had a protective and beneficial influence on the restoration of structural integrity and metabolism in sex accessory glands.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号