排序方式： 共有23条查询结果，搜索用时 15 毫秒
1.
The present study aims to ascertain the influence of gamma-amino butyric acid (GABA)(A or B) receptors on arginine vasopressin (AVP) release in vitro and determine whether E(2) modulates GABA-AVP interaction. Within 10 min of ewe killing, saggital midline hypothalamic slices (from the anterior preoptic area to the mediobasal hypothalamus along with the median eminence, 2-mm thick, two per ewe) were dissected, placed in oxygenated minimum essential media (MEM)-alpha at 4 degrees C and within 2 h were singly perifused at 37 degrees C with oxygenated MEM-alpha (pH 7.4; flow rate 0.15 ml/min), either with or without E(2) (24 pg/ml). After 4-h equilibration, 10-min fractions were collected for 4 h interposed with a 10-min exposure at 60 min to a specific GABA(A or B) receptor agonist or antagonist at various doses (0.1-10 mm). GABA(A) (muscimol; no E(2), n = 7 perifusion chambers, with E(2), n = 11) or GABA(B) (baclofen; no E(2), n = 8, with E(2), n = 15) agonists (10 mm) did not influence AVP concentrations. However, AVP release increased (p < 0.05) 20-30 min after exposure to 10 mm GABA(A or B) antagonists (bicuculline, no E(2), n = 7: from 4.6 +/- 0.7 to 33.0 +/- 0.4, with E(2), n = 17: from 11.9 +/- 1.4 to 32.8 +/- 6.0; CGP52432, with E(2), n = 14: from 14.0 +/- 2.6 to 28.8 +/- 3.9 pg/ml). At the end of the collection period, hypothalamic slices responded to KCl (100 mm) with AVP efflux (p < 0.05). GABA(B) but not GABA(A) antagonist-stimulated AVP release was enhanced in the presence of E(2). In summary, AVP release is under the inhibitory influence of GABA input with further potentiation by E(2) through GABA(B) receptors in vitro. 相似文献
2.
Analytical partitioning of four trace metals in estuarine sediments collected from eight sites in South Mosquito Lagoon near Kennedy Space Center, in terms of four different categories was accomplished using four different extraction techniques. The concentrations of the four trace metals, Zn, Mn, Cd, and Cu, released in interstitial water extract, 1 N ammonium acetate extract, conc. HCl extract and fusion extract of sediments as well as their concentrations in water samples collected from the same location were determined using flame atomic absorption technique. From the analytical results the percentages of total amount of each metal distributed among four different categories, interstitial water phase, acetate extractable, acid extractable and detrital crystalline material, were determined. Our results suggest that analytical partitioning of trace metals in estuarine sediments may be used to study the mechanism of incorporation of trace metals with sediments from natural waters. A correlation between the seasonal variation in the concentration of acetate extractable trace metals in the sediment and similar variation in their concentration in water was observed. A mechanism for the release of trace metals from estuarine sediments to natural water is also suggested. 相似文献
3.
4.
The present study aims at ascertaining the influence of α1‐adrenoreceptors on arginine vasopressin (AVP) release in vitro and determine whether E2 modulates the α1‐adrenoreceptor and AVP interaction. Ten minutes after ewe killing, sagittal midline hypothalamic slices (from the anterior preoptic area to the mediobasal hypothalamus with the median eminence, 2 mm thick, 2 per sheep) were dissected, placed in oxygenated minimum essential media‐α (MEM‐α) at 4°C and within 2 h were singly perifused at 37°C with oxygenated MEM‐α (pH 7.4; flow rate 0.15 ml/min), either with or without E2 (24 pg/ml). After 4 h equilibration, 10 min fractions were collected for 4 h interposed with 10 min exposure at 60 min to a specific α1‐adrenoreceptor agonist or antagonist at various doses (0.1–10 mm ). At the end of all perifusions, slices responded to KCl (100 mm ) with AVP efflux (p < 0.05). Release of AVP was enhanced (p < 0.05) by the α1‐adrenoreceptor agonist (methoxamine 10 mm ; no E2, n = 7 perifusion chambers: from 14.3 ± 2.7 to 20.9 ± 3.9, with E2, n = 10: from 10.7 ± 1.2 to 18.4 ± 3.4 pg/ml) or the antagonist (thymoxamine 10 mm ; no E2, n = 5: from 9.5 ± 3.1 to 30.4 ± 6.0, with E2, n = 10: from 10.8 ± 0.9 to 39.1 ± 6.3 pg/ml). With the agonist, the response occurred only at 80 min (p < 0.05) both in the presence and absence of E2. Whereas, after the antagonist, values were higher (p < 0.05) throughout the post‐treatment period (80–170 min) without E2, but declined by 150 min in the presence of E2. Furthermore, the response to the α1‐adrenoreceptor antagonist was greater (p < 0.05; 90–140 min) than the agonist only in the presence of E2. In conclusion, these results reveal direct α1‐adrenoreceptor‐mediated control of the hypothalamic AVP neuronal system which is modulated by E2. 相似文献
5.
Anand Kumar Pandey Gurcharan Singh Dhaliwal Sarvpreet Singh Ghuman Jagir Singh Ajeet Kumar Sudhir Kumar Agarwal 《Tropical animal health and production》2012,45(1):293-298
The current study was aimed to establish the impact of progesterone supplementation (norgestomet progestagen) between days 4 to 10 post-ovulation on subsequent luteal profile and conception rate in buffaloes. The 28 Murrah buffaloes of second to fourth parity, having normal reproductive organs, were estrus synchronized by double PGF2α protocol at 11 days apart. The buffaloes were inseminated during mid- to late estrus and thereafter repeated at 24 h interval. The buffaloes were randomly assigned into two groups: (1) control (no treatment, n?=?14) and (2) treatment group (CRESTAR ear implant, n?=?14). The CRESTAR ear implant (3 mg, norgestomet progestagen) was inserted subcutaneous between days 4 to 10 post-ovulation. The ovaries were scanned at estrus and thereafter on days 4, 10, 16, 21, and 40 post-ovulation to examine the preovulatory follicle (POF) and corpus luteum (CL) diameter. Each ultasonography was followed by blood sample collection for analysis of plasma progesterone concentrations following ovulation. The conception rate was similar (p?>?0.05) between treated and control buffaloes. The pregnant buffalo of the control group had larger (p?<?0.05) POF diameter than nonpregnant counterparts. The CL diameter was similar (p?>?0.05) in both treated and untreated control as well as in their pregnant and nonpregnant buffaloes of the respective groups. The plasma progesterone concentrations were higher (p?<?0.05) in the treatment group on the day 10 post-ovulation as compared to the control buffaloes. It is concluded that norgestomet supplementation had no impact on conception rate and CL diameter but enhances the plasma progesterone concentrations following treatment in buffaloes. 相似文献
6.
M. P. Menon G. S. Ghuman J. James K. Chandra D. C. Adriano 《Water, air, and soil pollution》1990,50(3-4):343-353
The pH, conductivity and the concentration of 15 selected elements were measured in the water extracts of five coal fly ash samples collected from Savannah River Site (SRS) and one from South Carolina Electric and Gas (SCE & G) power plant. This work was intended to study the differences in the physico-chemical properties of SRS fly ash samples relative to those of a reference sample (SCE & G) and to make fly ash-amended composts for agricultural use. Similar analyses were also performed in water extracts of a commercial organic manure, ‘Gotta Grow’, that was composted with one of the fly ash samples (SRS 484-D) in different proportions. Our results show that fly ash samples used in this study differ considerably in pH, conductivity, and elemental composition and that transition metals appear to bind more tightly on smaller particles than on larger ones. The elementally rich manure, ‘Gotta Grow’, is not suitable to study the effects of fly ash on the elemental release from fly ash-amended composts. Low grade or home-made organic composts are being investigated as possible choice for making ly ash-amended composts. 相似文献
7.
SPS Ghuman J Singh M Honparkhe D Dadarwal GS Dhaliwal AK Jain 《Reproduction in domestic animals》2010,45(4):600-607
This study was conducted on summer anoestrous buffalo heifers to monitor the efficacy of melatonin for induction of ovulation and ovarian cyclicity. During pre‐treatment period of 24 days, the ovarian dynamics of five cycling and 10 summer anoestrous heifers was monitored on each alternate day using a transrectal ultrasound scanner. Thereafter, during treatment period, these 10 anoestrous heifers along with additional seven anoestrous heifers were randomly allocated into non‐implanted (n = 5) and implanted (n = 12, one melatonin implant/50 kg, 18 mg melatonin/implant) group. Non‐implanted heifers were monitored on each alternate day till the confirmation of second‐ovulation in implanted heifers. Pre‐treatment period revealed the presence of dominant follicles in anoestrous heifers which attained the diameter comparable with ovulatory follicles of cycling heifers but failed to ovulate and regressed. Between 6 and 36 days (15.3 ± 2.9 days) post‐treatment, all the implanted heifers (p < 0.05) exhibited ovulation of dominant follicles; however none of the non‐implanted heifers ovulated during the corresponding period. The first‐interovulatory period in implanted heifers ranged between 8 and 28 days (18.0 ± 1.8 days). The implanted heifers with short (≤16 days) interovulatory period had short‐lived corpus luteum (CL) that had smaller diameter and secreted less progesterone (p < 0.05). The diameter of CL was large (p < 0.05) and plasma progesterone was high (p < 0.05) following second‐ovulation compared with first‐ovulation in implanted heifers. In conclusion, using melatonin implants, ovulatory size nonovulatory follicles observed in summer anoestrous buffalo heifers can be successfully ovulated to initiate ovarian cyclicity. 相似文献
8.
9.
The aim of the study was to evaluate oxidative stress around parturition in normally calved and dystocia-affected buffaloes
and the clinical efficacy of vitamin E and selenium (Se) in reducing the effects in buffaloes suffering from dystocia. Plasma
cortisol concentration, erythrocytic malondialdehyde (MDA) level and superoxide dismutase (SOD) and glutathione peroxidase
(GSH-Px) activities were evaluated in dystocia-affected (supplemented (n = 8) and unsupplemented (n = 5) with vitamin E and Se) and normally calved (unsupplemented; n = 6) buffaloes. The decline in plasma cortisol concentration, MDA level and SOD activity was greater in the group of dystocia-affected
buffaloes supplemented with vitamin E and Se (78.62 ± 2.7%, 13.38 ± 9.75% and 28.83 ± 7.72%, respectively) than in the unsupplemented
group (54.33 ± 12.62%, 3.48 ± 4.16% and 17.69 ± 12.93%, respectively). These results suggests that supplementation with antioxidants
like vitamin E and Se may be beneficial in reducing oxidative stress in dystocia-affected buffaloes in the immediate postpartum
period. 相似文献
10.
Performance of tomato when irrigated with sodic waters particularly under drip irrigation is not well known. A field experiment
was conducted for 3 years to study the response of tomato crop to sodic water irrigation on a sandy loam soil. Irrigation
waters having 0, 5 and 10 mmolc L−1 residual sodium carbonate (RSC) were applied through drip and furrow irrigation to two tomato cultivars, Edkawi (a salt tolerant cultivar) and Punjab Chhuhara (PC). High RSC of irrigation water significantly increased soil pH, ECe and exchangeable sodium percentage progressively; the
increases were higher in furrow compared to drip irrigation. Effect of high RSC on increasing bulk density and decreasing
infiltration rate of soil was also pronounced in furrow-irrigated plots. Higher soil moisture and lower salinity near the
plant was maintained under drip irrigation than under furrow irrigation. Performance of the two cultivars was significantly
different; pooled over 2002–03 and 2003–04 seasons, PC yielded 38.8 and 30.0 Mg ha−1 and Edkawi yielded 31.8 and 22.9 Mg ha−1 under drip and furrow irrigation, respectively. At RSC10, cultivar PC produced 38 and 46% higher fruit yield than cultivar Edkawi under drip and furrow irrigation, respectively. Reduction in fruit yield at higher RSC was due to lower fruit weight under
drip irrigation and due to reduced fruit number as well as fruit weight under furrow irrigation. Decrease in fruit weight
was more pronounced in cultivar Edkawi than in cultivar PC. Increase in RSC lowered quality of the fruits except the ascorbic acid content. High RSC under drip irrigation, in general,
had lesser deteriorating effect on the fruit quality particularly for cultivar PC than under furrow irrigation. For obtaining high tomato yield and better-quality fruits using high RSC sodic waters, drip
irrigation should be preferred over furrow irrigation. Better performance of local cultivar PC compared to Edkawi at medium and high RSC suggests that cultivars categorized as tolerant to salinity should be evaluated in the sodic environment
particularly when irrigated with high RSC sodic waters. 相似文献