染料木素对卵巢切除大鼠学习记忆能力的影响

目的：探讨染料木素对卵巢切除大鼠学习记忆能力的影响及作用机制。方法：将40只SD雌性大鼠随机分为用假手术组、去卵巢对照组、染料木素高剂量、低剂量组、17β-雌二醇组,切除卵巢建立学习和记忆能力受损的模型。灌胃给药6周后Morris水迷宫测定各组大鼠学习记忆能力,免疫组化法观察大鼠海马微管相关蛋白（tau蛋白）阳性表达情况,测定大鼠脑组织中乙酰胆碱酯酶（AchE）、乙酰胆碱转移酶（ChaT）、超氧化物歧化酶（SOD）的活性及丙二醛（MDA）的含量,观察海马组织超微结构变化。结果：大鼠切除卵巢后Morris水迷宫测定的学习记忆能力显著下降,微管相关蛋白（tau蛋白）异常磷酸化阳性表达率增高,前脑皮质中超氧化物歧化酶（SOD）、乙酰胆碱转移酶（ChaT）活性降低,丙二醛（MDA）含量、乙酰胆碱酯酶（AchE）活性增高。低剂量的染料木素可以发挥类雌激素样作用,改善去卵巢大鼠的以上症状。结论：染料木素对卵巢切除导致的学习和记忆能力下降有改善作用,低剂量效果显著,其可能的机制是：抑制了脑内AchE的活性,使乙酰胆碱的降解减少;增强脑组织抗氧化能力;稳定微管相关蛋白（tau蛋白）,降低tau蛋白异常磷酸化水平。     

Effect of melatonin on bone metabolism in ovariectomized rats.

To assess the effect of pharmacological dose of melatonin on bone metabolism in ovariectomized rats, urinary deoxypyridinoline (a marker of bone resorption) and calcium excretion, circulating levels of calcium, phosphorus and bone alkaline phosphatase activity (a marker of bone formation), and bone mineral density (BMD), mineral content (BMC) and bone area (BA) of total body, were measured in adult rats for up to 60 days after surgery. Rats received melatonin in the drinking water (25 microg/ml water) or drinking water alone. Urinary deoxypyridinoline increased significantly after ovariectomy by 51% (30 days after surgery) and by 47% (60 days after surgery). The increase in urinary deoxypyridinoline found 30 days after ovariectomy was not observed in melatonin-treated rats. Urinary calcium concentration was similar in the 4 experimental groups studied, as was the circulating calcium concentration at every time interval examined. Fifteen days after surgery, a significant increase in serum phosphorus and bone alkaline phosphatase levels occurred in ovariectomized rats receiving melatonin as compared to their controls. Sixty days after surgery BMD, BMC and BA decreased significantly in ovariectomized rats, an effect not modified by melatonin. Serum estradiol decreased significantly by 30 days after ovariectomy to attain values close to the limit of detection of the assay by 60 days after ovariectomy. The results support the conclusion that a pharmacological amount of melatonin modifies bone remodeling after ovariectomy and that the effect may need adequate concentrations of estradiol.     

Action of acetylsalicylic acid administered by different routes on the blood and buccal tissues of rats]

Sixty female Sprague-Dawley rats, with an average weight of 120 g, have been used in this study. The experimental groups received twice a day 1 ml of a 2% acetyl-salicylic acid suspension in methyl-cellulose either per os or i.p. The control groups received methyl-cellulose without asprin. The blood was collected before any treatment and each day during the week for the purpose of counting cells. The experimental animals and their control were killed after 2, 4 and 8 days. A piece of endobuccal epithelium with its deeper tissues was cut off and frozen for histochemistry. The tissue sections were treated to show the basic enzymatic reactions of the cell. It was observed that: 1. most of the changes appear between the 4th and 8th day of the treatment: 2. depending on the administration route, certain blood cells show a peak. Microphages between the 4th and 6th day in injected animals. Lymphocytes at the same time, in the gavage group; 3. oral epithelium lesions are limited and appear lately; 4. underlying muscles are a constant target. The lesions are seen in both experimental groups as soon as the 2nd day. After a week, the lesions are more numerous. They are characterized by enzymatic inbalances with or without macrophages. The muscular cell is a real target for acetyl salicylic acid.     

Effects of dehydroepiandrosterone on passive avoidance in ovariectomized female rats of different age

The aim of the present work was to study the influence of long-term treatment with dehydroepiandrosterone (DHEA) in doses of 0.1 and 0.7 mg/kg, i.p. on the passive avoidance performance in the ovariectomized female rats of 5- and 18-month old. The results obtained indicated that DHEA administration during 7 days in dose of 0.1 mg/kg normalized the passive avoidance performance in the ovariectomized rats of 5-month old while DHEA administration during 7 days in dose of 0.7 mg/kg restored passive avoidance performance in the ovariectomized rats of 18-month old.     

Effect of proteolytic enzymes on antibiotic distribution when the preparations are administered by different routes]

The effect of proteolytic enzymes, such as terrilitine and chymotripsin on pharmacokinetics of morphocycline and streptomycin in rats after their administration by various routes was studied comparatively. The oral use of the enzymes or their introduction directly into the duodenum simultaneously or 30 minutes before the antibiotic administration did not increase the morphocycline and streptomycin levels in the biosubstrates tested. A tendency to a decrease in the serum and organ levels of the antibiotics in animals when used orally in combination with the enzymes was noted. When the drugs were administered intramuscularly, the morphocycline serum and organ levels in the rats increased insignificantly, while the streptomycin levels increased significantly. Administration of formalin as a stressor had an analogous effect which provided a supposition of a possibility of non-specific effect of the enzymes of distribution of the antibiotics on intramuscular injection of the enzymes in large doses having a local irritating effect.     

Effect of chitooligosaccharides on calcium bioavailability and bone strength in ovariectomized rats

Chitosan polymer with deacetylation degree of 93% was hydrolyzed with an endo-type chitosanase (35,000 U/g protein) with substrate to enzyme ratio of 1 to 1.5 for 18 h in a batch reactor, and then the resultant hydrolysates were fractionated into four different molecular weights using an ultrafiltration (UF) membrane reactor system. An in vitro study elucidated that four kinds of chitooligosaccharides (COSs) could efficiently inhibit the formation of insoluble calcium salts in the neutral pH. In vivo effects of COSs on Ca bioavailability were further studied in the osteoporosis modeling rats induced by ovariectomy and concurrent low calcium intake. During the experimental period corresponding to the menopause with the osteoporosis disease, calcium retention was increased and bone turnover was decreased by COS IV supplementation in the ovariectomized (OVX) rats. After the low Ca diet, COS IV diet including both normal level of calcium and vitamin D significantly decreased calcium loss in feces and increased calcium retention compared to the control diet. The levels of femoral total calcium, bone mineral density (BMD), and femoral strength were also significantly increased by the COS IV diet in a similar level to those of CPP diet group. In the present study, the results proved the beneficial effects of low molecular chitooligosaccharide (COS IV) in preventing negative mineral balance.     

Effect of herbal extract mixture on menopausal urinary incontinence in ovariectomized rats

The decline of estrogen production after menopause is contributing factor to urinary incontinence (UI), and particularly stress urinary incontinence (SUI). We determined the preventive effects of herbal extract mixture (HEM) on UI in ovariectomized Sprague Dawley rats. Female 9-weeks old rats were ovariectomized and treated with HEM (2.2, 11, or 55 mg/kg/day) for 8 weeks. The index of urinary bladder weight to body weight in the HEM and non-ovariectomized and non-treated (SHAM) groups were slightly higher than the ovariectomized, non-treated group (OVX). The contraction index of acetylcholine to KCl on detrusor smooth muscle strips in the HEM groups showed a dose-dependent recovery. HEM treatment also significantly improved collagen levels, as shown by Masson trichrome staining, as well as hydroxyproline levels in the urinary bladder. Serum estradiol levels in the HEM groups were higher than the OVX group. In conclusion, HEM increased estradiol levels in serum and improved factors related to urinary incontinence. The improvements in estradiol levels were related to changes in urinary incontinence.     

Effect of centrally administered somatostatin on pituitary thyrotropes in male rats

The effects of intracerebroventricularly administered somatostatin (SRIH-14 or -28) on growth and function of pituitary thyrotropes (TSH-cells) were examined in adult male Wistar rats. The animals were implanted with an intracerebroventricular cannula and after a recovery period, administered three 1g doses of SRIH-14 or -28 dissolved in 5l saline every second day. Controls were treated in the same way with the same volume of saline only. TSH-producing cells were studied using the peroxidase–antiperoxidase immunohistochemical procedure. Blood samples were collected for hormone (TSH) analyses 5 days after the last injection. Both SRIH-treatments significantly decreased (p < 0.05) all morphometric parameters obtained for TSH-cells in comparison with controls. The volume of TSH-cells decreased by 27%, nuclei by 44% and volume density by 33% in animals treated with SRIH-14. In animals treated with SRIH-28, these parameters were also significantly decreased (p < 0.05) (22%, 31%, and 25% respectively) compared to control rats. Serum concentrations of TSH were significantly decreased (p < 0.05) by 15% in SRIH-14- and by 12% in SRIH-28-treated animals in comparison with the controls. These observations suggest that centrally administered SRIH-14 or -28 is specifically involved in the control of growth and secretory activity of TSH cells.     

Hormonal regulation of proteins in the uterine secretion of ovariectomized rats and the implications for implantation and embryonic diapause.

Uterine secretions were obtained from long-term ovariectomized rats given progesterone for 10 days followed by oestrogen and progesterone. Analysis of the protein content was carried out using polyacrylamide disc gel electrophoresis at pH8-9 AND ALSO OF THE PROTEIN-SODIUM DODECYL SULPHATE COMPLEXES. When progesterone was given alone, there was a lack of high molecular weight proteins. When oestradiol was also given, a protein (mol. wt 70,000) was detected within 1 hr. At 13 to 20 hr after oestrogen, there was a shift towards the secretion of high molecular weight proteins when the secretion profiles were similar to those of normal pregnant animals at Day 5, the day of implantation in the rat. The hormonal regulation of the secretion proteins is discussed. The physiological aspects of implantation in terms of zona lysis, embryonic diapause and the release from diapause after oestrogen treatment are discussed with reference to the changes in the intraluminal proteins.     

Protein-nitrogen metabolism in the liver of rats intraperitoneally administered carminomycin]

It was found in the experiments with rats that in response to carminomycin administration in a single LD50 and the therapeutic doses during the treatment course the intracellular fond of the amino acids in the liver tissue increased, the autolytic processes activated, the activity of the transamination enzymes, histidine and ammonia lyases increased. The level of the residual nitrogen increased mainly at the expense of increased ammonia production and urea levels. These changes were more pronounced when the antibiotic was administered in LD50. Independent of the administration multiplicity and the antibiotic dosage they were of reversible nature and mainly disappeared by the end of the observation.     

Effect of isoflavone genistein on insulin receptors in perfused liver of ovariectomized rats

The experiments were carried out on ovariectomized Wistar rats. Their livers were perfused with basic perfusion medium (BPM) or BPM supplemented with isoflavone genistein, insulin or combination of the two factors. The obtained results support the hypothesis that genistein influences the kinetics of insulin binding to cell membranes changing the number of insulin receptors and dissociation constant (Kd). BPM supplementation with genistein decreased number of high affinity insulin receptors (HAIR) both in livers treated and untreated with insulin. The amount of HAIR diminished significantly from 610 +/- 77 x 10(-15) (no genistein) to 238 +/- 72 x 10(-15) mol/mg of membrane protein (supplement of genistein). Similarly, genistein reduced slightly the amount of HAIR even when added together with insulin (372 +/- 59 x 10(-15) mol/mg) in comparison to rats perfused with medium containing insulin but not the isoflavone (421 +/- 46 x 10(-15) mol/mg). Simultaneously, genistein decreased significantly Kd for HAIR (perfusion with BPM--1.44 +/- 0.18 x 10(-9) mol/l; perfusion with BMP + genistein--0.83 +/- 0.20 x 10(-9) mol/l). Such effects of genistein during liver perfision did not take place when the liver membranes were in vitro incubated with this xenobiotic.