Effect of Age on Hypertensive Stimuli and the Development of Hypertension in Brattleboro Rats

1979 ◽  
Vol 57 (3) ◽  
pp. 273-275 ◽  
Author(s):  
H. Dlouhá ◽  
J. Křeček ◽  
J. Zicha

1. In rats with inherited diabetes insipidus, unilateral nephrectomy plus drinking of 0·6% NaCl solution (saline) did not influence blood pressure in adult rats. However, when these factors applied before puberty, they produced hypertension. 2. We therefore analysed whether saline administration before puberty or unilateral nephrectomy before puberty was more important for this hypertensive response. 3. Saline drinking was found to be necessary for the response because hypertension was elicited by unilateral nephrectomy in adult rats only if saline consumption began before puberty.

1990 ◽  
Vol 51 (6) ◽  
pp. 721-727 ◽  
Author(s):  
Udo Bahner ◽  
Helmut Geiger ◽  
Miklos Palkovits ◽  
Detlev Ganten ◽  
Joachim Michel ◽  
...  

1985 ◽  
Vol 68 (1) ◽  
pp. 93-96 ◽  
Author(s):  
M. Rathaus ◽  
N. Kariv ◽  
J. Shapira ◽  
J. Bernheim

1. Current evidence suggests that the antidiuretic hormone (ADH) and changes in sodium balance influence renal prostaglandins (PGs). To separate these two mechanisms, the effect of sodium loading on the urinary excretion of PGE2 and PGF2α was studied in female Brattleboro rats with diabetes insipidus (DIHO) and compared with that in female, age matched, heterozygous Long Evans controls (LEHE). 2. Ten DIHO and ten LEHE rats had a normal sodium intake. In ten DIHO rats a 0.16% NaCl solution was supplied instead of drinking water for either 8 days (n = 5) or 14 days (n = 5). In two groups of LEHE rats, sodium loading was obtained with a 0.80% NaCl solution for the same study periods. Urine PGs were measured by radioimmunoassay in three 24 h urine collections for each rat. 3. Urine PGs were significantly increased in the 8 day loaded but not in the 14 day loaded LEHE rats. In DIHO rats, a non-significant increase in both PGE2 and PGF2α was present after 8 days of sodium loading, while PGE2 and the E/F ratio were decreased after 14 days of salt loading. 4. The findings suggest that the natriuresis induced by sodium loading in the rat may be mediated in part by increased production of PGs. In addition, it seems that ADH plays a role in this response.


1969 ◽  
Vol 68 (1, Pt.1) ◽  
pp. 38-44 ◽  
Author(s):  
Genaro M. Palmieri ◽  
Samuel Taleisnik

1994 ◽  
Vol 266 (4) ◽  
pp. F628-F632 ◽  
Author(s):  
A. Haramati ◽  
M. D. Lumpkin ◽  
S. E. Mulroney

Removal of one kidney results, within days, in accelerated growth of the remaining kidney. However, the mechanisms that underlie this compensatory renal hypertrophic response, particularly in the early time period following nephrectomy, are not understood. In this study we tested the hypothesis that removal of one kidney leads to a change in the pulsatile release of growth hormone (GH), which facilitates compensatory renal growth. Adult Wistar rats were implanted with Silastic cannulas in jugular veins and underwent either unilateral nephrectomy (UNX) or sham operation. Plasma levels of GH were determined 24 and 48 h after sham operation or UNX. Blood samples were taken every 20 min over a 6-h period from conscious, unrestrained animals. Pulsatile GH release was markedly elevated 24 h after UNX in both the amplitude of the surges as well as in the duration of release. Peak GH levels after 24 h were three- to fourfold higher in UNX rats compared with sham controls (417 +/- 75 vs. 119 +/- 23 ng/ml, P < 0.05). However, this enhanced release of GH appeared to be of short duration and began declining by 48 h post-UNX (peak level of 227 +/- 37 ng/ml, P < 0.05 vs. both 24 h UNX and sham controls). To examine whether this rise in GH release post-UNX contributed to the compensatory renal growth, rats underwent UNX and were immediately treated with an antagonist to GH-releasing factor (GRF-AN; i.e., [N-Ac-Tyr1,D-Arg2]GRF-(1-29) amide, 200 micrograms/kg twice daily), and the effects on GH release and renal growth were determined. Administration of GRF-AN significantly suppressed the increase in GH release post-UNX and was associated with a significant attenuation in renal growth 48 h post-UNX in GRF-AN-treated rats (8.7 +/- 2.6% vs. 22.7 +/- 3.0% in UNX controls, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Author(s):  
José João Mendes ◽  
João Viana ◽  
Filipe Cruz ◽  
Dinis Pereira ◽  
Sílvia Ferreira ◽  
...  

We aimed to investigate the association between blood pressure (BP) and tooth loss and the mediation effect of age. A cross-sectional study from a reference dental hospital was conducted from September 2017 to July 2020. Single measures of BP were taken via an automated sphygmomanometer device. Tooth loss was assessed through oral examination and confirmed radiographically. Severe tooth loss was defined as 10 or more teeth lost. Additional study covariates were collected via sociodemographic and medical questionnaires. A total of 10,576 patients were included. Hypertension was more prevalent in severe tooth loss patients than nonsevere tooth lost (56.1% vs. 39.3%, p < 0.001). The frequency of likely undiagnosed hypertension was 43.4%. The adjusted logistic model for sex, smoking habits and body mass index confirmed the association between continuous measures of high BP and continuous measures of tooth loss (odds ratio (OR) = 1.05, 95% CI: 1.03–1.06, p < 0.001). Age mediated 80.0% and 87.5% of the association between periodontitis with both systolic BP (p < 0.001) and diastolic BP (p < 0.001), respectively. Therefore, hypertension and tooth loss are associated, with a consistent mediation effect of age. Frequency of undiagnosed hypertension was elevated. Age, gender, active smoking, and BMI were independently associated with raised BP.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3568
Author(s):  
Bernardita Cayupe ◽  
Carlos Morgan ◽  
Gustavo Puentes ◽  
Luis Valladares ◽  
Héctor Burgos ◽  
...  

Prenatally malnourished rats develop hypertension in adulthood, in part through increased α1-adrenoceptor-mediated outflow from the paraventricular nucleus (PVN) to the sympathetic system. We studied whether both α1-adrenoceptor-mediated noradrenergic excitatory pathways from the locus coeruleus (LC) to the PVN and their reciprocal excitatory CRFergic connections contribute to prenatal undernutrition-induced hypertension. For that purpose, we microinjected either α1-adrenoceptor or CRH receptor agonists and/or antagonists in the PVN or the LC, respectively. We also determined the α1-adrenoceptor density in whole hypothalamus and the expression levels of α1A-adrenoceptor mRNA in the PVN. The results showed that: (i) agonists microinjection increased systolic blood pressure and heart rate in normotensive eutrophic rats, but not in prenatally malnourished subjects; (ii) antagonists microinjection reduced hypertension and tachycardia in undernourished rats, but not in eutrophic controls; (iii) in undernourished animals, antagonist administration to one nuclei allowed the agonists recover full efficacy in the complementary nucleus, inducing hypertension and tachycardia; (iv) early undernutrition did not modify the number of α1-adrenoceptor binding sites in hypothalamus, but reduced the number of cells expressing α1A-adrenoceptor mRNA in the PVN. These results support the hypothesis that systolic pressure and heart rate are increased by tonic reciprocal paraventricular–coerulear excitatory interactions in prenatally undernourished young-adult rats.


2020 ◽  
Vol 129 (6) ◽  
pp. 1310-1323
Author(s):  
Jennifer L. Magnusson ◽  
Craig A. Emter ◽  
Kevin J. Cummings

The role of serotonin in arterial blood pressure (ABP) regulation across states of vigilance is unknown. We hypothesized that adult rats devoid of CNS serotonin (TPH2−/−) have low ABP in wakefulness and NREM sleep, when serotonin neurons are active. However, TPH2−/− rats experience higher ABP than TPH2+/+ rats in wakefulness and REM only, a phenotype present only in older males and not females. CNS serotonin may be critical for preventing high ABP in males with aging.


1968 ◽  
Vol 109 (1) ◽  
pp. 127-135 ◽  
Author(s):  
I R Johnston ◽  
A P Mathias ◽  
F. Pennington ◽  
D. Ridge

1. Purified liver nuclei from adult rats separate into two main zones when centrifuged in the slow-speed zonal rotor. One zone contains diploid nuclei, the other tetraploid. 2. The effect of age on the pattern of rat liver ploidy was examined. Tetraploid nuclei are virtually absent from young animals. They increase in proportion steadily with age. Partial hepatectomy disturbs the pattern of ploidy. 3. The zonal centrifuge permits the separation of diploid, tetraploid, octaploid and hexadecaploid nuclei from mouse liver. 4. Rat liver nuclei are isopycnic with sucrose solutions of density 1·35 at 5°.


1963 ◽  
Vol 42 (6) ◽  
pp. 1465-1466 ◽  
Author(s):  
E.L. Nichols ◽  
D.K. Hotchkiss ◽  
S.L. Balloun

Heart ◽  
1986 ◽  
Vol 55 (6) ◽  
pp. 560-568 ◽  
Author(s):  
B A Towfiq ◽  
J Weir ◽  
J M Rawles

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