Differences in renal ammonia metabolism in male and female kidney

Renal ammonia metabolism has a major role in the maintenance of acid-base homeostasis. Sex differences are well recognized as an important biological variable in many aspects of renal function, including fluid and electrolyte metabolism. However, sex differences in renal ammonia metabolism have not been previously reported. Therefore, the purpose of the current study was to investigate sex differences in renal ammonia metabolism. We studied 4-mo-old wild-type C57BL/6 mice fed a normal diet. Despite similar levels of food intake, and, thus, protein intake, which is the primary determinant of endogenous acid production, female mice excreted greater amounts of ammonia, but not titratable acids, than did male mice. This difference in ammonia metabolism was associated with fundamental structural differences between the female and male kidney. In the female mouse kidney, proximal tubules account for a lower percentage of the renal cortical parenchyma compared with the male kidney, whereas collecting ducts account for a greater percentage of the renal parenchyma than in male kidneys. To further investigate the mechanism(s) behind the greater ammonia excretion in female mice, we examined differences in the expression of proteins involved in renal ammonia metabolism and transport. Greater basal ammonia excretion in females was associated with greater expression of PEPCK, glutamine synthetase, NKCC2, Rhbg, and Rhcg than was observed in male mice. We conclude that there are sex differences in basal ammonia metabolism that involve both renal structural differences and differences in expression of proteins involved in ammonia metabolism.

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Differences in acidosis-stimulated renal ammonia metabolism in the male and female kidney

AJP Renal Physiology ◽

10.1152/ajprenal.00244.2019 ◽

2019 ◽

Vol 317 (4) ◽

pp. F890-F905 ◽

Cited By ~ 4

Author(s):

Autumn N. Harris ◽

Hyun-Wook Lee ◽

Lijuan Fang ◽

Jill W. Verlander ◽

I. David Weiner

Keyword(s):

Phosphoenolpyruvate Carboxykinase ◽

Collecting Duct ◽

Ammonia Excretion ◽

Volume Density ◽

Male Mice ◽

Ammonia Metabolism ◽

Female Mice ◽

Predominant Component ◽

Acid Load ◽

Acid Loading

Renal ammonia excretion is a critical component of acid-base homeostasis, and changes in ammonia excretion are the predominant component of increased net acid excretion in response to metabolic acidosis. We recently reported substantial sex-dependent differences in basal ammonia metabolism that correlate with sex-dependent differences in renal structure and expression of key proteins involved in ammonia metabolism. The purpose of the present study was to investigate the effect of sex on the renal ammonia response to an exogenous acid load. We studied 4-mo-old C57BL/6 mice. Ammonia excretion, which was less in male mice under basal conditions, increased in response to acid loading to a greater extent in male mice, such that maximal ammonia excretion did not differ between the sexes. Fundamental structural sex differences in the nonacid-loaded kidney persisted after acid loading, with less cortical proximal tubule volume density in the female kidney than in the male kidney, whereas collecting duct volume density was greater in the female kidney. To further investigate sex-dependent differences in the response to acid loading, we examined the expression of proteins involved in ammonia metabolism. The change in expression of phosphoenolpyruvate carboxykinase and Rh family B glycoprotein with acid loading was greater in male mice than in female mice, whereas Na+-K+-2Cl– cotransporter and inner stripe of the outer medulla intercalated cell Rh family C glycoprotein expression were significantly greater in female mice than in male mice. There was no significant sex difference in glutamine synthetase, Na+/H+ exchanger isoform 3, or electrogenic Na+-bicarbonate cotransporter 1 variant A protein expression in response to acid loading. We conclude that substantial sex-dependent differences in the renal ammonia response to acid loading enable a similar maximum ammonia excretion response.

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Role of the Renal Androgen Receptor in Ammonia Metabolism

AJP Renal Physiology ◽

10.1152/ajprenal.00260.2021 ◽

2021 ◽

Author(s):

Autumn N. Harris ◽

Rebeca A Castro ◽

Hyun-Wook Lee ◽

Jill W. Verlander ◽

I. David Weiner

Keyword(s):

Sex Differences ◽

Androgen Receptor ◽

Proximal Tubule ◽

Ammonia Excretion ◽

Volume Density ◽

Plasma Testosterone ◽

Kidney Size ◽

Ammonia Metabolism ◽

Female Mice

Background: There are sex differences in renal ammonia metabolism and structure, many of which are mediated by testosterone. This study's goal was to determine the role of renal expression of testosterone's canonical receptor, androgen receptor (AR), in these sexual dimorphisms. Methods: We studied mice with kidney-specific AR deletion (KS-AR-KO) generated using Cre/loxP techniques; control mice were Cre-negative littermates (WT). Results: In male, but not female, mice, KS-AR-KO increased ammonia excretion, which eliminated sex differences. Although renal structural size typically parallel ammonia excretion, KS-AR-KO decreased kidney size, cortical proximal tubule volume density and cortical proximal tubule cell height in males; neither were altered in females and collecting duct volume density was unaltered in both sexes. Analysis of key protein involved in ammonia handling showed in male mice that KS-AR-KO increased both PEPCK and NKCC2 expression, and decreased NHE3 and NBCe1-A expression. In female mice, KS-AR-KO did not alter these parameters. These effects occurred even though KS-AR-KO did not alter plasma testosterone, food intake or serum Na+, K+, or HCO3- significantly in either sex. Conclusions: AR-dependent signaling pathways in male, but not female, kidney regulate PEPCK and NKCC2 expression and lead to the sexual differences in ammonia excretion. Opposing effects on NHE-3 and NBCe1-A expression likely limit the magnitude of ammonia excretion changes. Since AR is not present in the TAL, the effect of KS-AR-KO on NKCC2 expression is indirect. Finally, AR mediates the greater kidney size and PT volume density in male than in female mice.

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Iba1+ cell density and morphology classification at postnatal day 10 in four hippocampal subregions of female and male C57BL/6J mice

10.1101/2021.08.11.456021 ◽

2021 ◽

Author(s):

Danielle Guez-Barber ◽

Max Wragan ◽

Dana Raphael ◽

Haley M. Phillips ◽

Kira Lu ◽

...

Keyword(s):

Sex Differences ◽

Cell Density ◽

Female Rats ◽

Male Rats ◽

Lower Percentage ◽

Male Mice ◽

Male And Female ◽

Female Mice ◽

Mouse Hippocampus ◽

The Brain

Microglia maintain normal brain function and support the brain′s response to disease and injury. The hippocampus is an area of focus for microglial study due to its central role in numerous behavioral and cognitive functions. Interestingly, microglia and related cells in the hippocampus and throughout the brain are distinct in male vs. female rodents, even in early life. Indeed, postnatal day (P)-dependent sex differences in number, density, and morphology of microglia-like cells have been reported in certain hippocampal subregions. For example, P3 female mice have more phagocytic microglia in dentate gyrus (DG) molecular layer (Mol) and CA1-3 stratum oriens (SO) regions vs. male mice, while P8 — but not P15 — male rats have more volume immunoreactive for markers of microglia-like cells (Iba1 and CD68) in the CA1 stratum radiatum (SR) vs. female rats. In the mouse, P10 is roughly equivalent to human term gestation, making it a common time point to study for many translationally-relevant neurobiological processes. However, sex differences in hippocampal microglia have not been examined in the P10 mouse hippocampus. In addition, key subregions of the hippocampus — CA3 SR, DG hilus — have not yet been assessed for sex differences in microglia. To address these knowledge gaps, we quantified Iba1+ cell densities and classified Iba1+ cell morphology in P10 male and female C57BL/6J mice. Four subregions in the bilateral anterior hippocampus were analyzed in 40-μm coronal sections: DG Mol (Mol), DG Hilus, CA1 SR and stratum lacunosum moleculare (CA1), and CA3 SR and stratum lucidum (CA3). Light microscope images (40x) were analyzed offline for Iba1+ cell density and morphology by an observer blind to sex. The morphology of each Iba1+ cell was used to place cells into one of four previously-published categories: Round or ameboid (round-ish soma, no processes), Stout (round-ish soma, short process), Thick (irregular soma with few, thick processes), or Thin (irregular soma with multiple thin processes). Analysis of Iba1+ cell density shows no difference between male and female mice in Mol, Hilus, CA3, or CA1 (male n=6, female n=7). However, morphology classification shows a sex-dependent difference in the Mol and Hilus, with female mice having a greater percentage of Thick Iba1+ cells vs. male mice (Mol, Hilus), and a lower percentage of Thin Iba1+ cells vs. male mice (Mol). With our analysis, it is unclear whether this greater percentage of thick and lower percentage of thin Iba1+ cells in the female vs. male hippocampus means Iba1+ microglia in female mice are ″younger″ or ″more active″ than those in male mice. However, these data are important as they reveal sex differences in Iba1+ microglia in the P10 mouse hippocampus. We discuss these results in the context of the large literature on sex differences in rodent microglia in the early postnatal period.

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Sex Differences in the Relation Between Frailty and Endothelial Dysfunction in Old Mice

The Journals of Gerontology Series A ◽

10.1093/gerona/glab317 ◽

2021 ◽

Author(s):

Jazmin A Cole ◽

Mackenzie N Kehmeier ◽

Bradley R Bedell ◽

Sahana Krishna Kumaran ◽

Grant D Henson ◽

...

Keyword(s):

Sex Differences ◽

Endothelial Function ◽

Vascular Function ◽

Mesenteric Artery ◽

Frailty Index ◽

Mesenteric Arteries ◽

Male Mice ◽

Male And Female ◽

Female Mice ◽

Age Related

Abstract Vascular endothelial function declines with age on average, but there is high variability in the magnitude of this decline within populations. Measurements of frailty, known as frailty index (FI), can be used as surrogates for biological age, but it is unknown if frailty relates to the age-related decline in vascular function. To examine this relation, we studied young (4-9 months) and old (23-32 months) C57BL6 mice of both sexes. We found that FI was greater in old compared with young mice, but did not differ between old male and female mice. Middle cerebral artery (MCA) and mesenteric artery endothelium-dependent dilation (EDD) also did not differ between old male and female mice; however, there were sex differences in the relations between FI and EDD. For the MCA, FI was inversely related to EDD among old female mice, but not old male mice. In contrast, for the mesenteric artery, FI was inversely related to EDD among old male mice, but not old female mice. A higher FI was related to a greater improvement in EDD with the superoxide scavenger TEMPOL in the MCAs for old female mice and in the mesenteric arteries for old male mice. FI related to mesenteric artery gene expression negatively for extracellular superoxide dismutase (Sod3) and positively for interleukin-1β (Il1b). In summary, we found that the relation between frailty and endothelial function is dependent on sex and the artery examined. Arterial oxidative stress and pro-inflammatory signaling are potential mediators of the relations of frailty and endothelial function.

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Sex differences in renal and metabolic responses to a high-fructose diet in mice

AJP Renal Physiology ◽

10.1152/ajprenal.00403.2014 ◽

2015 ◽

Vol 308 (5) ◽

pp. F400-F410 ◽

Cited By ~ 17

Author(s):

Nikhil Sharma ◽

Lijun Li ◽

C. M. Ecelbarger

Keyword(s):

Sex Differences ◽

Glucose Transporter ◽

Collecting Duct ◽

Urine Volume ◽

Thick Ascending Limb ◽

Male Mice ◽

Male And Female ◽

Female Mice ◽

High Fructose Diet ◽

High Fructose

High fructose intake has been associated with increased incidences of renal disease and hypertension, among other pathologies. Most fructose is cleared by the portal system and metabolized in the liver; however, systemic levels of fructose can rise with increased consumption. We tested whether there were sex differences in the renal responses to a high-fructose diet in mice. Two-month-old male and female C57BL6/129/SV mice ( n = 6 mice per sex per treatment) were randomized to receive control or high-fructose (65% by weight) diets as pelleted chow ad libitum for 3 mo. Fructose feeding did not significantly affect body weight but led to a 19% and 10% increase in kidney weight in male and female mice, respectively. In male mice, fructose increased the expression (∼50%) of renal cortical proteins involved in metabolism, including glucose transporter 5 (facilitative fructose transporter), ketohexokinase, and the insulin receptor (β-subunit). Female mice had lower basal levels of glucose transporter 5, which were unresponsive to fructose. However, female mice had increased urine volume and plasma K+ and decreased plasma Na+ with fructose, whereas male mice were less affected. Likewise, female mice showed a two- to threefold reduction in the expression Na+-K+-2Cl− cotransporter 2 in the thick ascending limb and aquaporin-2 in the collecting duct with fructose relative to female control mice, whereas male mice had no change. Overall, our results support greater proximal metabolism of fructose in male animals and greater distal tubule/collecting duct (electrolyte homeostasis) alterations in female animals. These sex differences may be important determinants of the specific nature of pathologies that develop in association with high fructose consumption.

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Oral prescription opioid-seeking behavior in male and female mice

10.1101/621177 ◽

2019 ◽

Author(s):

Alysabeth G. Phillips ◽

Dillon J. McGovern ◽

Soo Lee ◽

Kyu Ro ◽

David T. Huynh ◽

...

Keyword(s):

Sex Differences ◽

Oral Drug ◽

Prescription Opioid ◽

Male Mice ◽

Self Administration ◽

Female Mice ◽

Seeking Behavior ◽

Opioid Users ◽

Psychomotor Stimulation

AbstractA significant portion of prescription opioid users self-administer orally rather than intravenously. Animal models of opioid addiction have demonstrated that intravenous cues are sufficient to cause drug-seeking. However, intravenous models may not model oral users, and the preference to self-administer orally appears to be partially influenced by the user’s sex. Our objectives were to determine whether oral opioid-associated cues are sufficient for relapse and whether sex differences exist in relapse susceptibility. Mice orally self-administered escalating doses of oxycodone under postprandial (prefed) or non-postprandial (no prefeeding) conditions. Both sexes demonstrated robust cue-induced reinstatement. In separate mice we found that oral oxycodone cues were sufficient to reinstate extinguished oral oxycodone-seeking behavior in the absence of postprandial or prior water self-administration training. During self-administration, we found that female mice earned significantly more mg/kg oxycodone than male mice. Follow-up studies indicated sex differences in psychomotor stimulation and plasma oxycodone/oxymorphone following oral oxycodone administration. In addition, gonadal steroid studies were performed in which we found divergent responses where ovariectomy enhanced and orchiectomy suppressed oral self-administration. While the suppressive effects of orchiectomy were identified across doses and postprandial conditions, the enhancing effects of ovariectomy were selective to non-postprandial conditions. These studies establish that 1) oral drug cues are sufficient to cause reinstatement that is independent of prandial conditions and water-seeking behavior, 2) earned oral oxycodone is larger in female mice compared with male mice potentially through differences in psychomotor stimulation and drug metabolism, and 3) gonadectomy produces divergent effects on oral oxycodone self-administration between sexes.

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Sex differences in nociceptor translatomes contribute to divergent prostaglandin signaling in male and female mice

10.1101/2020.07.31.231753 ◽

2020 ◽

Author(s):

Diana Tavares-Ferreira ◽

Pradipta R. Ray ◽

Ishwarya Sankaranarayanan ◽

Galo L. Mejia ◽

Andi Wangzhou ◽

...

Keyword(s):

Sex Differences ◽

Cortical Neurons ◽

Affinity Purification ◽

Male Mice ◽

Protective Behaviors ◽

Pain Mechanisms ◽

Female Mice ◽

Mechanistic Basis ◽

High Doses ◽

Neuronal Functions

ABSTRACTBackgroundThere are clinically relevant sex differences in acute and chronic pain mechanisms, but we are only beginning to understand their mechanistic basis. Transcriptome analyses of rodent whole dorsal root ganglion (DRG) have revealed sex differences, mostly in immune cells. We examined the transcriptome and translatome of the mouse DRG with the goal of identifying sex differences.MethodsWe used Translating Ribosome Affinity Purification (TRAP) sequencing and behavioral pharmacology to test the hypothesis that nociceptor (Nav1.8 expressing neurons) translatomes would differ by sex.ResultsWe found 66 genes whose mRNA were sex-differentially bound to nociceptor ribosomes. Many of these genes have known neuronal functions but have not been explored in sex differences in pain. We focused on Ptgds, which was increased in female mice. The mRNA encodes the prostaglandin D2 (PGD2) synthesizing enzyme. We observed increased Ptgds protein and PGD2 in female mouse DRG. The Ptgds inhibitor AT-56 caused intense pain behaviors in male mice but was only effective at high doses in females. Conversely, female mice responded more robustly to another major prostaglandin, PGE2, than did male mice. Ptgds protein expression was also higher in female cortical neurons, suggesting DRG findings may be generalizable to other nervous system structures.ConclusionsNociceptor TRAP sequencing (TRAP-seq) reveals unexpected sex differences in one of the oldest known nociceptive signaling molecule families, the prostaglandins. Our results demonstrate that translatome analysis reveals physiologically relevant sex differences important for fundamental protective behaviors driven by nociceptors.

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Microthrombi Correlates With Infarction and Delayed Neurological Deficits After Subarachnoid Hemorrhage in Mice

Stroke ◽

10.1161/strokeaha.120.029753 ◽

2020 ◽

Vol 51 (7) ◽

pp. 2249-2254 ◽

Cited By ~ 1

Author(s):

Ari Dienel ◽

Remya Ammassam Veettil ◽

Sung-Ha Hong ◽

Kanako Matsumura ◽

Peeyush Kumar T. ◽

...

Keyword(s):

Sex Differences ◽

Subarachnoid Hemorrhage ◽

Infarct Volume ◽

Neurological Deficits ◽

Behavioral Performance ◽

Large Artery ◽

Male Mice ◽

Functional Deficits ◽

Female Mice ◽

Correlation Analyses

Background and Purpose: Delayed neurological deficits are a devastating consequence of subarachnoid hemorrhage (SAH), which affects about 30% of surviving patients. Although a very serious concern, delayed deficits are understudied in experimental SAH models; it is not known whether rodents recapitulate the delayed clinical decline seen in SAH patients. We hypothesized that mice with SAH develop delayed functional deficits and that microthrombi and infarction correlate with delayed decline. Methods: Adult C57BL/6J mice of both sexes were subjected to endovascular perforation to induce SAH. Mice were allowed to survive for up to 1 week post-ictus and behavioral performance was assessed daily. Postmortem microthrombi, large artery diameters (to assess vasospasm), and infarct volume were measured. These measures were analyzed for differences between SAH mice that developed delayed deficits and SAH mice that did not get delayed deficits. Correlation analyses were performed to identify which measures correlated with delayed neurological deficits, sex, and infarction. Results: Twenty-three percent of males and 47% of females developed delayed deficits 3 to 6 days post-SAH. Female mice subjected to SAH had a significantly higher incidence of delayed deficits than male mice with SAH. Mice that developed delayed deficits had significantly more microthrombi and larger infarct volumes than SAH mice that did not get delayed deficits. Microthrombi positively correlated with infarct volume, and both microthrombi and infarction correlated with delayed functional deficits. Vasospasm did not correlate with either infarction delayed functional deficits. Conclusions: We discovered that delayed functional deficits occur in mice following SAH. Sex differences were seen in the prevalence of delayed deficits. The mechanism by which microthrombi cause delayed deficits may be via formation of infarcts.

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Sex differences in adaptive downregulation of pre-macula densa sodium transporters with ANG II infusion in mice

AJP Renal Physiology ◽

10.1152/ajprenal.00088.2009 ◽

2010 ◽

Vol 298 (1) ◽

pp. F187-F195 ◽

Cited By ~ 12

Author(s):

Swasti Tiwari ◽

Lijun Li ◽

Shahla Riazi ◽

Veerendra K. Madala Halagappa ◽

Carolyn M. Ecelbarger

Keyword(s):

Sex Differences ◽

Plasma Testosterone ◽

Sodium Reabsorption ◽

Thick Ascending Limb ◽

Ang Ii ◽

Male Mice ◽

Male And Female ◽

Female Mice ◽

Sodium Transporters ◽

Pressure Natriuresis

An increase in blood pressure (BP) due to angiotensin II (ANG II) infusion or other means is associated with adaptive pressure natriuresis due to reduced sodium reabsorption primarily in proximal tubule (PT) and thick ascending limb (TAL). We tested the hypothesis that male and female mice would show differential response to ANG II infusion with regard to the regulation of the protein abundance of sodium transporters in the PT and TAL and that these responses would be modulated by aging. Young (∼3 mo) and old (∼21 mo) male and female mice were infused with ANG II at 800 ng·kg body wt−1·min−1 by osmotic minipump for 7 days or received a sham operation. ANG II increased mean arterial pressure (MAP), measured by radiotelemetry, significantly more in male mice of both ages (increased ∼30–40 mmHg), compared with females (increased ∼15–25 mmHg). On day 1, MAP was also significantly increased in old mice, relative to young ( P = 0.01). ANG II infusion was associated with a significant decline in plasma testosterone (to <30% of control male) in male mice and rise in young female mice (to 478% of control female). No sex differences were found in the upregulation of the sodium hydrogen exchanger abundance on Western blots observed with ANG II infusion or the downregulation of the sodium phosphate cotransporter; however, aging did impact on some of these changes. Male mice (especially young) also had significantly reduced levels of the TAL bumetanide-sensitive Na-K-2Cl cotransporter (to 60% of male control), while young females showed an increase (to 126% of female control) with ANG II infusion. These sex differences do not support impaired pressure natriuresis in male mice, but might reflect a greater need and attempt to mount an appropriately BP-metered natriuretic response by additional downregulation of TAL sodium reabsorption.

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THE EFFECT OF GENISTEIN ON THE FERTILITY OF MICE

Journal of Endocrinology ◽

10.1677/joe.0.0130094 ◽

1955 ◽

Vol 13 (1) ◽

pp. 94-100 ◽

Cited By ~ 14

Author(s):

JUNE EAST

Keyword(s):

Adult Male ◽

Normal Diet ◽

Vaginal Opening ◽

Male Mice ◽

Intact Female ◽

Female Mice ◽

Adult Females ◽

Daily Intakes

SUMMARY Synthetic genistein, 5:7:4′-trihydroxy-isoflavone, proved to be oestrogenic (that is to say produced vaginal cornification) when included in the normal diet of immature, spayed and intact female mice in amounts calculated to give daily intakes of 2, 10 and 15 mg respectively. Consumption of genistein also precipitated vaginal opening in immature mice. The fertility of adult male mice fed 15 mg genistein daily for 22–25 days was more severely affected than that of adult females similarly treated for 31–55 days. Of ten males, five were rendered sterile and the fertility of three others was impaired. Two of ten females did not mate and abnormal numbers of still-born young were produced by the remaining animals. Four males and one female did not recover fertility when transferred to normal rations.

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