EFFECT OF RATE CORROSION OF Mg AND Mg ALLOY ON RENAL NITRIC OXIDE SYNTHASE ACTIVITY IN MALE AND FEMALE RATS

Hyperglycemia affects male and female vascular beds differently. We have previously shown that 1 week after the induction of diabetes with streptozotocin (STZ), male and female rats exhibit differences in aortic endothelial function. To examine this phenomenon further, aortic responses were studied in male and female rats 8 weeks after the induction of diabetes (intermediate stage). Endothelium-dependent vasodilation (EDV) to acetylcholine (ACh) was measured in phenylephrine (PE) pre-contracted rat aortic rings. Concentration response curves to PE were generated before and after L-NAME, a nitric oxide synthase (NOS) inhibitor. Furthermore, mRNA expression of endothelial nitric oxide synthase (eNOS) and NADPH oxidase subunit (Nox1) were determined. At 8 weeks, diabetes impaired EDV to a greater extent in female than male aortae. Furthermore, the responsiveness to PE was significantly enhanced only in female diabetic rats, and basal NO, as indicated by the potentiation of the response to PE after L-NAME, was reduced in female diabetic rat aortae to the same levels as in males. In addition, eNOS mRNA expression was decreased, while the Nox1 expression was significantly enhanced in diabetic female rats. These results suggest that aortic function in female diabetic rats after 8 weeks exhibits a more prominent impairment and that NO may be involved.

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Different responses of nitric oxide synthase inhibition on morphine-induced antinociception in male and female rats

Pathophysiology ◽

10.1016/j.pathophys.2010.05.004 ◽

2011 ◽

Vol 18 (2) ◽

pp. 143-149 ◽

Cited By ~ 5

Author(s):

Mahmoud Hosseini ◽

Zahra Taiarani ◽

Mosa Al-Reza Hadjzadeh ◽

Soodabeh Salehabadi ◽

Maryam Tehranipour ◽

...

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Female Rats ◽

Male And Female ◽

Male And Female Rats ◽

Oxide Synthase

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Diabetes induces sex-dependent changes in neuronal nitric oxide synthase dimerization and function in the rat gastric antrum

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00406.2006 ◽

2007 ◽

Vol 292 (3) ◽

pp. G725-G733 ◽

Cited By ~ 75

Author(s):

Pandu R. R. Gangula ◽

William L. Maner ◽

Maria-Adelaide Micci ◽

Robert E. Garfield ◽

Pankaj Jay Pasricha

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Neuronal Nitric Oxide Synthase ◽

Gastric Antrum ◽

Female Rats ◽

Male Rats ◽

Organ Bath ◽

Intragastric Pressure ◽

Male And Female ◽

Oxide Synthase

Diabetic gastroparesis is a disorder that predominantly affects women. However, the biological basis of this sex bias remains completely unknown. In this study we tested the hypothesis that a component of this effect may be mediated by the nitrergic inhibitory system of the enteric nervous system. Age-matched male and female Sprague-Dawley rats were studied 8 or 12 wk after streptozotocin (55 mg/kg body wt ip)-induced sustained hyperglycemia and compared with controls. Solid gastric emptying (GE) studies were performed in all the groups. Changes in gastric antrum neuronal nitric oxide synthase (nNOS) mRNA and protein levels were analyzed by real-time PCR and Western immunoblotting, respectively. nNOS dimerization studies were performed using low-temperature SDS-PAGE. In vitro nitrergic relaxation (area under curve/mg tissue wt) was studied after the application of electric field stimulation in an organ bath. Changes in intragastric pressure (mmHg·s) in freely moving rats in the presence or absence of NG-nitro-l-arginine methyl ester (nitric oxide synthase inhibitor) were examined by an ambulatory telemetric method. After diabetes induction, GE is delayed in both male and female rats. However, diabetic females exhibited significant delayed GE than in diabetic males. Compared with male controls, gastric nNOS expression and nitrergic relaxation were substantially elevated in healthy female control rats, accompanied by significantly reduced intragastric pressure. The active dimeric form and dimer-to-monomer ratio of nNOSα were also higher in healthy females compared with male rats ( P < 0.05). Diabetic females, but not males, showed significant ( P < 0.05) impairment in both gastric nNOSα dimerization and nitrergic relaxation, accompanied by an increase in intragastric pressure. Our data provide evidence that females may have a greater dependency on the nitrergic mechanisms in health. Furthermore, diabetes seems to affect the nitrergic system to a greater extent in females than in males. Together, these changes may account for the greater vulnerability of females to diabetic gastric dysfunction.

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Effects of sex differences on constitutive nitric oxide synthase expression and activity in response to pressure overload in rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00883.2007 ◽

2007 ◽

Vol 293 (5) ◽

pp. H2650-H2658 ◽

Cited By ~ 20

Author(s):

Xavier Loyer ◽

Patricia Oliviero ◽

Thibaud Damy ◽

Estelle Robidel ◽

Françoise Marotte ◽

...

Keyword(s):

Nitric Oxide ◽

Sex Differences ◽

Nitric Oxide Synthase ◽

Pressure Overload ◽

Left Ventricular ◽

Female Rats ◽

Male Rats ◽

Male And Female ◽

Constitutive Nitric Oxide Synthase ◽

Oxide Synthase

Clinical studies have documented sex differences in left ventricular (LV) hypertrophy patterns, but the mechanisms are so far poorly defined. This study aimed to determine whether 1) severe pressure overload altered expression and/or activity of cardiac constitutive nitric oxide synthase (NOS1 and NOS3) and 2) these changes were modulated according to sex. Analyses were performed 0.4–20 wk after thoracic aortic constriction (TAC) in male and female Wistar rats. Male rats with TAC exhibited early signs of cardiac dysfunction, as shown by echocardiographic and LV end-diastolic pressure measurements, whereas females with TAC exhibited higher LV hypertrophy (+96% vs. males at 20 wk; P < 0.05). After TAC, cardiac NOS1 expression was rapidly induced (0.4 wk) and stable afterward in males ( P < 0.05 vs. sham groups), whereas it was delayed in females. Accordingly, specific NOS1 activity was increased by 2 wk in male rats with TAC (+122%; P < 0.001 vs. sham groups) and only by 20 wk in females (+220%; P < 0.001 vs. sham groups). NOS1 activity was correlated with NOS1 level. Regarding cardiac NOS3, expression was unaffected by TAC, and the decrease in activity observed at early and late times in male and female rats with TAC, respectively, is shown to be related to NOS3 allosteric regulator caveolin-1 level. The data demonstrated a unique sex-dependent regulation of the constitutive NOSs in response to TAC in rats; such a difference might play a role in the sex-dependent adaptability of the heart in response to pressure overload.

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