Noradrenergic content and turnover rate in kidney and heart shows gender and strain differences

Abstract

The objective of this study was to compare strain and gender differences in kidney and heart norepinephrine (NE) content and turnover rate in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR, SHR/a, and SHR/y). Our laboratory has shown that the Y chromosome has a significant effect on blood pressure in the SHR model of hypertension through the use of two new rat stains, SHR/a and SHR/y, to study the Y chromosome. SHR/a have a SHR autosomal genetic background with a WKY Y chromosome, whereas the SHR/y rats have a WKY autosomal genetic background with a SHR Y chromosome. Tissues were homogenized after alpha-methyl-DL-p-tyrosine injection and analyzed for NE. The male kidney NE content was significantly lower in the WKY compared with the SHR, SHR/y, and SHR/a. Kidney and heart NE content was significantly higher in females compared with males in all strains except the SHR/y. The WKY and SHR/y females had significantly lower kidney NE turnover rates, and the SHR and SHR/a females had significantly higher kidney NE turnover rates than strain-matched males. This study suggests both a strain and gender difference in sympathetic nervous system activity through noradrenergic neurotransmission.

Sympathetic Regulation of the Renal Functions in Rats Reciprocally Congenic for Chromosome 1 Blood Pressure Quantitative Trait Locus

“…Under this condition, the denervation elicited significant decreases of the NE levels in all four of the strains compared to the level of the sham-operated controls. Caplea et al showed in their recent communication that the chemical denervation caused a time-dependent log-linear reduction of the renal NE content up to 6 h, which could be used to calculate the NE turnover rate (5). Based on their work, the NE turnover rates were provisionally calculated in the present study.…”

“…The NE turnover rate was calculated according to the method originally described by Brodie et al (20) and used more recently by Caplea et al (5).…”

Interactions between the sympathetic nervous system and the kidneys in arterial hypertension

“…Thus, in SHR renal sympathetic innervation is more dense [16] and develops faster [10] during the first two postnatal weeks than in normotensive Wistar -Kyoto rats (WKY). Furthermore, renal norepinephrine content is approximately two times higher in newborn [10] and approximately 1.5 -3 times higher in adult SHR [17] compared to age-and sex-matched WKY. Since renal NGF mRNA expression was elevated in newborn SHR compared to WKY [11] or normotensive Donryu rats (DRY) [12] it has been suggested that this factor may contribute to renal sympathetic hyperinnervation in SHR [13].…”

“…In keeping with this finding, neonatal sympathectomy elicits elevations in renal RNA and protein concentrations during renal maturation, i.e., during postnatal days 10-20 [14]. In spontaneously hypertensive rats (SHR) renal sympathetic innervation is enhanced [10,16,17] and neonatal sympathectomy is associated with a decrease in long-term arterial pressure. Together, these findings suggest that a certain level of trophic stimulation during renal development may be required in order to maintain arterial pressure at a normal level whereas a lack of trophic stimulation such as in GDNF +/ À mice or in rats with increased renal sympathetic innervation may contribute to the pathogenesis of arterial hypertension.…”

Psychometric characteristics of type-D personality scale and comparision type-D personality among uniersity students

“…Sex differences obtained in the present study showing some differences In mood in males and females; men are more aggressive and stubborn while the women try to avoid the problems [10]. Studies show that, the activity of the sympathetic system and the secretion of the adrenaline hormone in men in response to stressful stimuli is greater than women [11,12]. Although the data related to cardiovascular problems is difficult to interpret, but some studies support the idea that sex differences in cardiovascular responses may explain the difference rate in cardiovascular disease and mortality rate in women and men.…”