scholarly journals Antihypertensive Effects of Onion on NO Synthase Inhibitor-induced Hypertensive Rats and Spontaneously Hypertensive Rats

2003 ◽  
Vol 67 (6) ◽  
pp. 1305-1311 ◽  
Author(s):  
Yoko SAKAI ◽  
Tetsuo MURAKAMI ◽  
Yukiko YAMAMOTO
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
No Synthase ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
No Synthase Inhibitor ◽  
Synthase Inhibitor

Does a general alteration in nitric oxide synthesis system occur in spontaneously hypertensive rats?

1994 ◽  
Vol 266 (1) ◽  
pp. H272-H278 ◽  
Author(s):  
J. Xiao ◽  
P. K. Pang
Keyword(s):  
Nitric Oxide ◽  
Spontaneously Hypertensive Rats ◽  
No Synthase ◽  
Hypertensive Rats ◽  
Synthesis System ◽  
Spontaneously Hypertensive ◽  
Proliferation Of Lymphocytes ◽  
General Activation ◽  
Wistar Kyoto ◽  
Synthase Inhibitor

Immune dysfunction has been reported in spontaneously hypertensive rats (SHR). The current study investigated interactions between macrophages or vascular smooth muscle cells (VSMC) and lymphocytes in SHR and examined the role of nitric oxide (NO) in this interaction. SHR macrophages significantly inhibited the proliferation of lymphocytes from SHR and the genetic control, Wistar-Kyoto rats (WKY). This inhibition was reversed by a NO synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA). SHR VSMC also significantly inhibited the proliferation responses of lymphocytes from SHR and WKY. The inhibition was cell density dependent. In addition, L-NMMA fully reversed the inhibition by SHR VSMC. Upon stimulation, the macrophages and VSMC from SHR produced a significantly higher amount of NO compared with those from WKY. These results suggest that the overproduction of NO was involved in the interaction between macrophages or VSMC and lymphocytes in SHR. Increased NO synthase activity in macrophages and VSMC may indicate a general activation of the NO synthesis system in SHR. The alteration of the NO synthesis system may be an important factor contributing to the lymphocyte depression in hypertension.

scholarly journals Oxidative stress induces BH4 deficiency in male, but not female, SHR

2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Ellen E. Gillis ◽  
Krystal N. Brinson ◽  
Olga Rafikova ◽  
Wei Chen ◽  
Jacqueline B. Musall ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Spontaneously Hypertensive Rats ◽  
No Synthase ◽  
Hypertensive Rats ◽  
Male And Female ◽  
Spontaneously Hypertensive ◽  
No Bioavailability ◽  
Renal Inner Medulla ◽  
Relative Deficiency ◽  
To Receive

We previously published that female spontaneously hypertensive rats (SHR) have significantly greater nitric oxide (NO) bioavailability and NO synthase (NOS) enzymatic activity in the renal inner medulla (IM) compared with age-matched males, although the mechanism responsible remains unknown. Tetrahydrobiopterin (BH4) is a critical cofactor required for NO generation, and decreases in BH4 as a result of increases in oxidative stress have been implicated in the pathogenesis of hypertension. As male SHR are known to have higher levels of oxidative stress compared with female SHR, we hypothesized that relative BH4 deficiency induced by oxidative stress in male SHR results in lower levels of NOS activity in renal IM compared with females. Twelve-week-old male and female SHR were randomized to receive tempol (30 mg/kg/day via drinking water) or vehicle for 2 weeks. Tempol treatment did not affect blood pressure (BP) in either sex, but reduced peroxynitrite levels only in males. Females had more total biopterin, dihydrobiopterin (BH2), and BH4 levels in renal IMs than males, and tempol treatment eliminated these sex differences. Females had greater total NOS activity in the renal IM than males, and adding exogenous BH4 to the assay increased NOS activity in both sexes. This sex difference in total NOS and the effect of exogenous BH4 were abolished with tempol treatment. We conclude that higher oxidative stress in male SHR results in a relative deficiency of BH4 compared with females, resulting in diminished renal NOS activity in the male.

scholarly journals The Impact of Four Different Classes of Anesthetics on the Mechanisms of Blood Pressure Regulation in Normotensive and Spontaneously Hypertensive Rats

2013 ◽  
pp. 471-478 ◽  
Author(s):  
M. BENCZE ◽  
M. BEHULIAK ◽  
J. ZICHA
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Renin Angiotensin System ◽  
No Synthase ◽  
Hypertensive Rats ◽  
Major Drawback ◽  
Angiotensin System ◽  
Spontaneously Hypertensive ◽  
The Impact

Most anesthetics induce characteristic hemodynamic changes leading to blood pressure (BP) reduction but the role of renin-angiotensin system (RAS), sympathetic nervous system (SNS) and nitric oxide (NO) synthesis in this BP reduction is unknown. We therefore studied the influence of four widely used anesthetics – pentobarbital (P), isoflurane (ISO), ketamine-xylazine (KX) and chloralose-urethane (CU) – on the participation of these vasoactive systems in BP maintenance. BP effects elicited by the acute sequential blockade of RAS (captopril), SNS (pentolinium) and NO synthase (L-NAME) were compared in conscious and anesthetized Wistar or spontaneously hypertensive rats (SHR). Except for pentobarbital all studied anesthetics evidenced by diminished BP responses to pentolinium. The absolute pentolinium-induced BP changes were always greater in SHR than Wistar rats. KX anesthesia eliminated BP response to pentolinium and considerably enhanced BP response to NO synthase inhibition in SHR. In both rat strains the anesthesia with ISO or CU augmented BP response to captopril, decreased BP response to pentolinium and attenuated BP response to NO synthase inhibition. In conclusion, pentobarbital anesthesia had a modest influence on BP level and its maintenance by the above vasoactive systems. Isoflurane and chloralose-urethane anesthesia may be used in cardiovascular experiments if substantial BP decrease due to altered contribution of RAS, SNS and NO to BP regulation does not interfere with the respective research aim. Major BP reduction (namely in SHR) due to a complete SNS absence is a major drawback of ketamine-xylazine anesthesia.

The participation of brain NO synthase in blood pressure control of adult spontaneously hypertensive rats

2006 ◽  
Vol 297 (1-2) ◽  
pp. 21-29 ◽  
Author(s):  
Silvie Hojná ◽  
Michaela Kadlecová ◽  
Zdenka Dobešová ◽  
Věra Valoušková ◽  
Josef Zicha ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Control ◽  
Spontaneously Hypertensive Rats ◽  
Pressure Control ◽  
No Synthase ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive
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