scholarly journals Stress-dependent and gender-specific neuroregulatory roles of the apelin receptor in the hypothalamic–pituitary–adrenal axis response to acute stress

2012 ◽  
Vol 216 (1) ◽  
pp. 99-109 ◽  
Author(s):  
M J F Newson ◽  
G R Pope ◽  
E M Roberts ◽  
S J Lolait ◽  
A-M O'Carroll

The neuropeptide apelin is expressed in hypothalamic paraventricular and supraoptic nuclei and mediates its effects via activation of the apelin receptor (APJ). Evidence suggests a role for apelin and APJ in mediating the neuroendocrine response to stress. To understand the physiological role of APJ in regulation of the hypothalamic–pituitary–adrenal (HPA) axis, we measured ACTH and corticosterone (CORT) plasma levels in male and female mice lacking APJ (APJ knockout, APJ KO) and in wild-type controls, in response to a variety of acute stressors. Exposure to mild restraint, systemic injection of lipopolysaccharide (LPS), insulin-induced hypoglycaemia and forced swim (FS) stressors, elevated plasma ACTH and CORT levels in wild-type mice. Acute mild restraint significantly increased plasma ACTH and CORT to a similar level in APJ KO mice as in wild-type mice. However, an intact APJ was required for a conventional ACTH, but not CORT, response to LPS administration in male mice and to insulin-induced hypoglycaemia in male and female mice. In contrast, APJ KO mice displayed an impaired CORT response to acute FS stress, regardless of gender. These data indicate that APJ has a role in regulation of the HPA axis response to some acute stressors and has a gender-specific function in peripheral immune activation of the HPA axis.

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 520 ◽  
Author(s):  
Katiuska Satué ◽  
Esterina Fazio ◽  
Ana Muñoz ◽  
Pietro Medica

In cycling females, the periovulatory period is characterized by stimulation of the hypothalamic pituitary adrenal (HPA) axis. The aim of present study was to analyze the pattern and interrelationships among adrenocorticotropic hormone (ACTH), cortisol (CORT), aldosterone (ALD) and electrolytes (sodium—Na+, potassium—K+ and chloride—Cl−) during periovulatory period in cycling mares. Venous blood samples were obtained daily from a total of 23 Purebred Spanish broodmares, aged 7.09 ± 2.5 years, from day −5 to day +5 of estrous cycle, considering day 0, the day of ovulation. Plasma ACTH was measured by a fluorescent immunoassay kit, serum CORT and ALD by means of a competitive ELISA immunoassay, and plasma Na+, K+ and Cl− were quantified by an analyzer with selective electrodes for the three ions. ACTH showed higher concentrations at day 0 compared to days −5 to −1 and +1 to +3 (p < 0.05). CORT showed higher concentrations at day 0 compared to days −5 to −2 and +1 to +5 (p < 0.05). ALD showed higher concentrations at day 0 compared to days −5 to −2 (p < 0.05) and +2 (p < 0.05). Na+ and Cl− showed higher concentrations at day 0, compared to day −5 and +5. K+ showed lower concentrations at day 0 compared to day +1 (p < 0.05). The significant correlations obtained between ACTH and CORT (r = 0.20) and between ACTH and ALD (r = 0.32) suggest that although ACTH may have an effect both on CORT and ALD, there are other very important determinants that could be considered. Hence, it is possible to presume that the pituitary adrenocortical response and ALD may be involved in the ovulatory mechanisms without a direct relation with electrolyte pattern.


2018 ◽  
Vol 75 (6) ◽  
pp. 1042-1049
Author(s):  
Seongjoon Park ◽  
Erkhembayar Nayantai ◽  
Toshimitsu Komatsu ◽  
Hiroko Hayashi ◽  
Ryoichi Mori ◽  
...  

Abstract The orexigenic hormone neuropeptide Y (NPY) plays a pivotal role in the peripheral regulation of fat metabolism. However, the mechanisms underlying the effects of sex on NPY function have not been extensively analyzed. In this study, we examined the effects of NPY deficiency on fat metabolism in male and female mice. Body weight was slightly decreased, whereas white adipose tissue (WAT) mass was significantly decreased as the thermogenic program was upregulated in NPY-/- female mice compared with that in wild-type mice; these factors were not altered in response to NPY deficiency in male mice. Moreover, lack of NPY resulted in an increase in luteinizing hormone (LH) expression in the pituitary gland, with concomitant activation of the estradiol-mediated thermogenic program in inguinal WAT, and alleviated age-related modification of adiposity in female mice. Taken together, these data revealed a novel intracellular mechanism of NPY in the regulation of fat metabolism and highlighted the sexual dimorphism of NPY as a promising target for drug development to reduce postmenopausal adiposity.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Quaisar Ali ◽  
Yonnie Wu ◽  
Tadashi Inagami ◽  
Tahir Hussain

Angiotensin II acting via Angiotensin II type 2 receptors (AT2Rs) is believed to be protective against blood pressure increase and affects renal function under pathophysiological condition. Recently we have observed that stimulation of AT2Rs in male obese Zucker rats has shifted the two opposing arms of renin angiotensin system (RAS) i.e. ACE-Ang II-AT1 vs ACE2/Ang-(1-7)-Mas. Evidence suggests that estrogen regulates RAS, including AT2R in female mice. We hypothesized that AT2R has a gender specific regulation of RAS. In the present study, we investigated the role of AT2Rs in regulating RAS components in male and female mice. Kidney cortex from AT2R knockout (AT2RKO) male and female mice and wild type (WT) with similar background (C57BL/6) of 20 weeks of age were used in the study. The cortical ACE expression (ng ACE/μg tissue) was significantly increased in AT2RKO mice (3±0.02) compared to WT males (1.9±0.02). LC/MS analysis of cortical tissue revealed that Ang II was also significantly increased in AT2RKO mice (WT: 31±3, AT2RKO: 47±3 fmoles/mg tissue). Deletion of AT2R significantly increased AT1R (204%, 204 of 100) expression and had no effect on renin activity compared to WT males. The cortical expression of ACE2 activity (WT: 113±8, AT2RKO: 40±11, RFU/min), Ang-(1-7) levels (WT: 7.3±1.4, AT2RKO: 3±0.8 fmoles/mg tissue) and Mas receptor (AT2RKO: 54±15, % of WT) was significantly decreased in AT2RKO males compared to WT. The cortical expression of the AT2R and MasR was 2-fold greater in WT females compared to WT male. The renin activity (WT: 32±2, AT2RKO: 21±0.3, RFU/min) and MasR expression (WT: 187.5±55, AT2KO: 47±9) was significantly decreased in AT2RKO females compared to the female WT. Interestingly, Ang-(1-7) level (WT: 5.7±0.7, AT2RKO 2.6±0.7 fmoles/mg tissue) was decreased but no changes in ACE or ACE2 activity was observed in AT2KO females compared to their WT, suggesting a role of non-ACE2 pathway. This study suggests that AT2R regulates ACE/ACE2 ratio-Ang II-AT1R expression negatively only in males, whereas in females, it regulates Ang-(1-7) potentially via non-ACE2 pathway. Such changes indicate a gender specific mechanisms potentially associated with AT2R-mediated regulation of renal function and blood pressure control.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mireia Tarrés-Gatius ◽  
Lluís Miquel-Rio ◽  
Leticia Campa ◽  
Francesc Artigas ◽  
Anna Castañé

AbstractAcute ketamine administration evokes rapid and sustained antidepressant effects in treatment-resistant patients. However, ketamine also produces transient perceptual disturbances similarly to those evoked by other non-competitive NMDA-R antagonists like phencyclidine (PCP). Although the brain networks involved in both ketamine actions are not fully understood, PCP and ketamine activate thalamo-cortical networks after NMDA-R blockade in GABAergic neurons of the reticular thalamic nucleus (RtN). Given the involvement of thalamo-cortical networks in processing sensory information, these networks may underlie psychotomimetic action. Since the GluN2C subunit is densely expressed in the thalamus, including the RtN, we examined the dependence of psychotomimetic and antidepressant-like actions of ketamine on the presence of GluN2C subunits, using wild-type and GluN2C knockout (GluN2CKO) mice. Likewise, since few studies have investigated ketamine’s effects in females, we used mice of both sexes. GluN2C deletion dramatically reduced stereotyped (circling) behavior induced by ketamine in male and female mice, while the antidepressant-like effect was fully preserved in both genotypes and sexes. Despite ketamine appeared to induce similar effects in both sexes, some neurobiological differences were observed between male and female mice regarding c-fos expression in thalamic nuclei and cerebellum, and glutamate surge in prefrontal cortex. In conclusion, the GluN2C subunit may discriminate between antidepressant-like and psychotomimetic actions of ketamine. Further, the abundant presence of GluN2C subunits in the cerebellum and the improved motor coordination of GluN2CKO mice after ketamine treatment suggest the involvement of cerebellar NMDA-Rs in some behavioral actions of ketamine.


Endocrinology ◽  
2018 ◽  
Vol 159 (6) ◽  
pp. 2363-2375 ◽  
Author(s):  
Ashley L Russell ◽  
M Riley Richardson ◽  
Bradly M Bauman ◽  
Ian M Hernandez ◽  
Samantha Saperstein ◽  
...  

2005 ◽  
Vol 289 (2) ◽  
pp. H586-H592 ◽  
Author(s):  
Paul Bridgman ◽  
Mark A. Aronovitz ◽  
Rahul Kakkar ◽  
Michael I. Oliverio ◽  
Thomas M. Coffman ◽  
...  

Left ventricular (LV) remodeling after myocardial infarction (MI) results from hypertrophy of myocytes and activation of fibroblasts induced, in part, by ligand stimulation of the ANG II type 1 receptor (AT1R). The purpose of the present study was to explore the specific role for activation of the AT1aR subtype in post-MI remodeling and whether gender differences exist in the patterns of remodeling in wild-type and AT1aR knockout (KO) mice. AT1aR-KO mice and wild-type littermates underwent coronary ligation to induce MI or sham procedures; echocardiography and hemodynamic evaluation were performed 6 wk later, and LV tissue was harvested for infarct size determination, morphometric measurements, and gene expression analysis. Survival and infarct size were similar among all male and female wild-type and AT1aR-KO mice. Hemodynamic indexes were also similar except for lower systolic blood pressure in the AT1aR-KO mice compared with wild-type mice. Male and female wild-type and male AT1aR-KO mice developed similar increases in LV chamber size, LV mass corrected for body weight (LV/BW), and myocyte cross-sectional area (CSA). However, female AT1aR-KO mice demonstrated no increase in LV/BW and myocyte CSA post-MI compared with shams. Both male and female wild-type mice demonstrated higher atrial natriuretic peptide (ANP) levels after MI, with female wild types being significantly greater than males. However, male and female AT1aR-KO mice developed no increase in ANP gene expression with MI despite an increase in LV mass and myocyte size in males. These data support that gender-specific patterns of LV and myocyte hypertrophy exist after MI in mice with a disrupted AT1aR gene, and suggest that myocyte hypertrophy post-MI in females relies, in part, on activation of the AT1aR. Further work is necessary to explore the potential mechanisms underlying these gender-based differences.


2018 ◽  
Vol 50 (8) ◽  
pp. 605-614
Author(s):  
Hong He ◽  
Katie Holl ◽  
Sarah DeBehnke ◽  
Chay Teng Yeo ◽  
Polly Hansen ◽  
...  

Type 2 diabetes is a complex disorder affected by multiple genes and the environment. Our laboratory has shown that in response to a glucose challenge, two-pore channel 2 ( Tpcn2) knockout mice exhibit a decreased insulin response but normal glucose clearance, suggesting they have improved insulin sensitivity compared with wild-type mice. We tested the hypothesis that improved insulin sensitivity in Tpcn2 knockout mice would protect against the negative effects of a high fat diet. Male and female Tpcn2 knockout (KO), heterozygous (Het), and wild-type (WT) mice were fed a low-fat (LF) or high-fat (HF) diet for 24 wk. HF diet significantly increases body weight in WT mice relative to those on the LF diet; this HF diet-induced increase in body weight is blunted in the Het and KO mice. Despite the protection against diet-induced weight gain, however, Tpcn2 KO mice are not protected against HF-diet-induced changes in glucose or insulin area under the curve during glucose tolerance tests in female mice, while HF diet has no significant effect on glucose tolerance in the male mice, regardless of genotype. Glucose disappearance during an insulin tolerance test is augmented in male KO mice, consistent with our previous findings suggesting enhanced insulin sensitivity in these mice. Male KO mice exhibit increased fasting plasma total cholesterol and triglyceride concentrations relative to WT mice on the LF diet, but this difference disappears in HF diet-fed mice where there is increased cholesterol and triglycerides across all genotypes. These data demonstrate that knockout of Tpcn2 may increase insulin action in male, but not female, mice. In addition, both male and female KO mice are protected against diet-induced weight gain, but this protection is likely independent from glucose tolerance, insulin sensitivity, and plasma lipid levels.


eNeuro ◽  
2017 ◽  
Vol 4 (4) ◽  
pp. ENEURO.0145-17.2017 ◽  
Author(s):  
Shireene Kalbassi ◽  
Sven O. Bachmann ◽  
Ellen Cross ◽  
Victoria H. Roberton ◽  
Stéphane J. Baudouin

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Fatima Mraiche ◽  
Larry Fliegel

Cardiac hypertrophy (CH) is heart growth in response to environmental demands, and a variety of hormonal, paracrine and autocrine stimuli. It is a means to reduce stress on the ventricular wall. The Na+/H+ exchanger isoform 1 (NHE1) has been implicated in the development and progression of CH. To better understand the involvement of NHE1, male and female transgenic mice that express cardiac specific active NHE1 expression were studied. N-line mice expressed wild-type NHE1, and K-line mice expressed activated NHE1. NHE activity of adult ventricular cardiomyocytes and protein expression were elevated by approximately 2 and 3-fold in the N- and K-line mice vs. control. The K-line female mice assessed by echocardiography demonstrated significant global cardiac dysfunction. Left ventricular fractional cell shortening and ejection fraction were significantly decreased in the K-line mice (23.1 ± 3.8% and 45.2 ± 6.9% K-line vs. 36.5 ± 1.1% and 66.4 ± 1.5% control, respectively; p<0.05). The K-line female mice also exhibit myocardial remodeling. The heart weight to body weight ratio was significantly greater in the K-line mice (143 ± 10.0% of control; P<0.05). Cross sectional area (K-line 195.6 ± 16.4% of control; p<0.05) and interstitial fibrosis (K-line: 275.4 ± 11.6% of control; p<0.05) were also elevated. Increased expression of active NHE1 protein in male mice was also much more detrimental than expression of the wild type protein as was seen with the female transgenic mice. Therefore, the NHE1 induced hypertrophic effect was not gender dependent. However, NHE1 expression induced gender specific differences with exercise. Exercising exaggerated the HW/BW ratio in female mice expressing activated NHE1 compared to males. These results suggest that gender specific activation of NHE1 may be critical in promoting hypertrophy in females in comparison with males.


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