Inhibition of Nischarin Expression Attenuates Rilmenidine-Evoked Hypotension and Phosphorylated Extracellular Signal-Regulated Kinase 1/2 Production in the Rostral Ventrolateral Medulla of Rats

Imidazoline (I1)-evoked hypotension is linked to enhanced phosphorylated extracellular signalregulated kinase (pERK)1/2 production in the rostral ventrolateral medulla (RVLM). Recent cell culture findings suggest that nischarin is a candidate for the I1 receptor. In the present study, nischarin antisense oligode-oxynucleotide (ODN) (AS1 or AS2), designed according to nischarin cDNA sequence, was administered intracisternally (i.c., 2 nmol/rat for 2 days) to knockdown central nischarin expression; control rats received the corresponding mismatched ODN (MM1 or MM2) or artificial cerebrospinal fluid (aCSF). We investigated the effects of AS1 or AS2 on nischarin expression in the RVLM, and on the hypotension and RVLM pERK1/2 production elicited by the I1-selective agonist rilmenidine (25 μ g/rat i.c.). Compared with aCSF, the mismatched ODN (MM1 or MM2) had no significant effect on RVLM nischarin expression or the cardiovascular and cellular (RVLM pERK1/2) responses elicited by rilmenidine. However, either antisense ODN substantially (>80%) reduced nischarin expression in the RVLM (AS1/MM1, 3 ± 1 versus 32 ± 2 positive cells; AS2/MM2, 4 ± 1 versus 31 ± 2 positive cells) and abrogated rilmenidine (I1)-evoked hypotension (AS1/MM1, −4.1 ± 0.9 versus −10.8 ± 1.9 mm Hg; AS2/MM2, −2.1 ± 1.1 versus −15.3 ± 2.5 mm Hg) and ERK1/2 activation in the RVLM (AS1/MM1, 10 ± 1 versus 15 ± 2 positive cells; AS2/MM2, 9 ± 1 versus 18 ± 2 positive cells). Finally, pERK1/2 generated by central I1 receptor activation is colocalized with nischarin in the RVLM neurons. This is the first evidence in vivo that nischarin plays a critical role in I1 receptor-mediated pERK1/2 production in the RVLM and the subsequent hypotension. Origianlly published Journal of Pharmacology and Experimental Therapeutics, Vol. 324, No. 1, Jan 200

Estrogen-dependent enhancement of NO production in the nucleus tractus solitarius contributes to ethanol-induced hypotension in conscious female rats

Background- Our previous pharmacological and cellular studies showed that peripheral (cardiac and vascular) NOS-derived NO is implicated in the estrogen-dependent hypotensive action of ethanol in female rats. The objective of this study was to test the hypothesis that enhanced NO production in the nucleus tractus solitarius (NTS) is implicated in the estrogen-dependent hypotensive action of ethanol. Methods- To achieve this goal, we utilized in vivo electrochemistry to measure real time changes in neuronal NO to investigate the acute effects of intragastric ethanol (0, 0.5 or 1 g/kg) on NO in NTS neurons, blood pressure (BP) and heart rate (HR) in conscious female rats in the absence (ovariectomized, OVX, rats) or presence of estrogen. Results- In sham operated (SO) rats, ethanol elicited dose-related increase in NTS NO and reduction in BP. These neurochemical and blood pressure effects of ethanol were absent in OVX rats. Whether the neurochemical effect of ethanol and the associated hypotension are dependent on rapid estrogen signaling was investigated. In OVX rats pretreated, 30 min earlier, with estrogen (E2, ug/kg), intragastric ethanol (1 g/kg) increased NTS NO and reduced BP and these responses were comparable to those obtained in SO rats. Conclusions- The present findings suggest that increased production of NO in NTS neurons contributes to ethanol-evoked hypotension in female rats. Further, ethanol enhancement of neuronal NO production in the brainstem is dependent on rapid estrogen signaling. Originally published Alcohol: Clinical and Experimental Research, Vol. 33, No. 2, Feb 200

Cannabinoid receptor 1 signaling in cardiovascular regulating nuclei in the brainstem: A review

Cannabinoids elicit complex hemodynamic responses in experimental animals that involve both peripheral and central sites. Centrally administered cannabinoids have been shown to predominantly cause pressor response. However, very little is known about the mechanism of the cannabinoid receptor 1 (CB1R)-centrally evoked pressor response. In this review, we provided an overview of the contemporary knowledge regarding the cannabinoids centrally elicited cardiovascular responses and the possible underlying signaling mechanisms. The current review focuses on the rostral ventrolateral medulla (RVLM) as the primary brainstem nucleus implicated in CB1R-evoked pressor response

Orchiectomy or androgen receptor blockade attenuates baroreflex-mediated bradycardia in conscious rats

Background: Previous studies have shown that testosterone enhances baroreflex bradycardia. Therefore, conscious unrestrained rats were used to investigate the role of the androgen receptor in the testosterone-mediated modulation of baroreflex bradycardia. Androgen depletion (3 weeks), and androgen receptor blockade (20–24 h), were implemented to test the hypothesis that testosterone influences baroreflex bradycardia via its activity at the androgen receptor in male rats. Phenylephrine (1–16 μg kg-1) was used to assess baroreflex bradycardia. Results: Androgen depletion attenuated baroreflex bradycardia (P < 0.01). The antiandrogen flutamide (5, 15, or 30 mg kg-1, s.c.) caused dose-related attenuation of baroreflex bradycardia in spite of a significant (P < 0.05) increase in serum testosterone. The latter did not lead to increased serum 17ß-estradiol level. Conclusion: The data suggest: 1) Androgen depletion or adequate androgen receptor blockade attenuates baroreflex bradycardia. 2) The reflex increase in serum testosterone may counterbalance the action of the lower doses (5 or 15 mg kg-1) of flutamide. 3) The absence of a change in serum 17ß-estradiol rules out its contribution to flutamide action on baroreflex bradycardia. Originally published BMC Pharmacology, Vol. 6, No. 2, Jan 200

Effect of Pollution and Ethylene-diurea on bean plants grown in KSA

The primary objectives of this investigation were to examine the interactive effects of three air quality treatments, ethylene-diurea (EDU) and two irrigation conditions on physiological characteristics of kidney beans (Phaseolus vulgaris L.) during its whole growth. These plants were grown in 15-open top chambers (OTC's). Ethylene-diurea (EDU) was used as a factor to evaluate O3 pollution impact on plant growth. The air quality treatments consisted of charcoal filtered (CF) air, nonfiltered (NF) air and ambient air (AA) were irrigated and non- irrigated. Leaf samples were collected from upper canopy positions six times (pre- EDU addition, week after four EDU's addition, at the time of harvesting). Maximal differences in leaf carbohydrate, N contents, pigments and total lipids were observed in response to moisture conditions in presence and absence of EDU applications. Significant reduction were noted for air quality treatments regarding carbohydrate and pigment fractions but not for all cases of leaf N and lipid contents under O3 effects only. Minimal differences were found for first EDU application while maximal ones were recorded of studied treatment at 200 mg l-1. The EDU treatments stimulated carbohydrate and pigment contents at the upper canopy position with higher levels for both NF and AA compared to untreated conditions. The NF and AA treatments caused lower total carbohydrate and pigment contents in the canopy position before harvesting of EDU applications. The stimulation in leaf carbohydrates by the EDU treatment, compared to the non-treated EDU of AA and NF treatments, provides a rational explanation for the counteracting effects of EDU against moderate exposures to O3 regarding grain yields in C3 plants. Keywords: Leaf contents, Moisture relations, EDU additions, pollution, Kidney bean

Effect of testosterone replacement or duration of castration on baroreflex bradycardia in conscious rats

BACKGROUND: In this study, we tested the hypothesis that 17β-estradiol contributes to testosterone-mediated restoration of baroreflex-mediated bradycardia in short-term (3 weeks) castrated rats. Further, a reported increase in serum testosterone after long-term (6 weeks) castration constituted a basis for testing the hypothesis that a spontaneous increase in serum testosterone or androstenedione in this model causes a commensurate increase in baroreflex-mediated bradycardia. RESULTS: Testosterone (1 week) replacement enhanced baroreflex-mediated bradycardia in short-term castrated rats without changing 17β-estradiol level. A spontaneous recovery of baroreflex-mediated bradycardia occurred following long-term castration, although circulating testosterone and androstenedione remained suppressed. CONCLUSION: The data suggest: 1) 17β-Estradiol does not contribute to testosterone restoration of the baroreflex-mediated bradycardia in short-term castrated rats. 2) The long-term modulation of baroreflex-mediated bradycardia occurs independent of androgens, or the baroreflex mechanism may become adapted to low levels of circulating androgens

Electrical performance study of a large area multicrystalline silicon solar cell using a current shunt and a micropotentiometer

In this paper, a new technique using a Current Shunt and a Micropotentiometer has been used to study the electrical performance of a large area multicrystalline silicon solar cell at outdoor conditions. The electrical performance is mainly described by measuring both cell short circuit current and open circuit voltage. The measurements of this cell by using multimeters suffer from some problems because the cell has high current intensity with low output voltage. So, the solar cell short circuit current values are obtained by measuring the voltage developed across a known resistance Current Shunt. Samples of the obtained current values are accurately calibrated by using a Micropotentiometer (μpot) thermal element (TE) to validate this new measuring technique. Moreover, the solar cell open circuit voltage has been measured. Besides, the cell output power has been calculated and can be correlated with the measured incident radiation

The Barriers of Implementing Governance Module in NGO in Arab Country: (The Case Study of Jordan)

The NGOs governances are always in continues development due to the changing life variables. As such, the previous studies of the NGOs performances and challenges always build a solid background for other researchers since they agree with many findings and conclusions globally and regionally. Therefore, this study represents a review that discussed the NGOs governance in Jordan as a case study of the Arab countries to conclude their barriers and obstacles. The article directed the knowledge for governance limitations in the developing countries in general and in Jordan in specific. Accordingly, it offered an enhancement on the theoretical background that can assess further studies. The NGOs in Arab countries have faced different barriers and challenges. These challenges could be divided to the international and regional levels. The main challenges that are categorised as  international level includes conflicted opinions during strategies creation, ideological stereotyped for possible associates , the situation framing that led to a competition for reaching the targets, the anxiety to fail that creates the depression of current rules and policies,the covering strategy that hides doubts, inner conflict, and disappointments. Whereas, weak governance, poor communications and poor internet usage are the main regional challenges of NGOs. According to the studies, the NGOs in Jordan are suffering from the mentioned obstacles besides the great lack of IT and internet usage, the significant social gap and weak regulations. As such, the consistent assessment of the NGOs governance progression will always be required. Keywords: NGOs, governance, barriers, Arab countries, Jorda

BIO-RESIDUAL STUDIES AND TREATING GUNNY SACKS WITH COUMARINS EXTRACT ON SEED PROTECTION AGAINST COWPEA BEETLE, CALLOSOBRUCHUS MACULATUS (FAB.)

Cowpea beetle, Callosobruchus maculatus (Fab.) (Coleoptera: Bruchidae), is the most important storage pest of cowpea. The quantification of cowpea losses through C. maculatus is very desirable. Coumarins possess controlling cowpea beetle. Both Ethanol and Chloroform extracts of Murraya, Kumquat and Celery plants were studied. Murraya ethanol extracts was more efficient than chloroform, as it induces higher percentage of reduction in the progeny, also protects cowpea seeds till 6 months when using the higher concentration (4%). Gunny sacks were treated with different extracts of the three of plants as an application method for protecting stored grain from infestation and ethanol extracts was a more effective than chloroform. The effect of the extracts on the weight loss of cowpea seeds was studied. The reduction percentage in weight increased from zero to 13% and 17.10% after nine months for both chloroform and ethanol kumquat extracts, respectively at the higher concentration used