scholarly journals Male sex hormones promote vagally mediated reflex airway responsiveness to cholinergic stimulation

2007 ◽  
Vol 292 (4) ◽  
pp. L908-L914 ◽  
Author(s):  
Jeffrey W. Card ◽  
James W. Voltz ◽  
Catherine D. Ferguson ◽  
Michelle A. Carey ◽  
Laura M. DeGraff ◽  
...  
Keyword(s):  
Sex Hormones ◽  
Ex Vivo ◽  
Airway Responsiveness ◽  
Male Mice ◽  
Cholinergic Stimulation ◽  
Intact Female ◽  
Reflex Mechanism ◽  
Female Mice ◽  
Male Sex

A sex disparity in airway responsiveness to cholinergic stimulation has been observed in laboratory mice in that males are considerably more responsive than females, but the basis for this difference is unclear. In this report, we demonstrate that male sex hormones promote murine airway responsiveness to cholinergic stimulation via vagus nerve-mediated reflex mechanisms. In tissue bath preparations, no sex-based differences were observed in the contractile responses of isolated tracheal and bronchial ring segments to carbachol, indicating that the mechanism(s) responsible for the in vivo sex difference is (are) absent ex vivo. Bilateral cervical vagotomy was found to abolish in vivo airway responsiveness to methacholine in male mice, whereas it did not alter the responses of females, suggesting a regulatory role for male sex hormones in promoting reflex airway constriction. To test this possibility, we next studied mice with altered circulating male sex hormone levels. Castrated male mice displayed airway responsiveness equivalent to that observed in intact females, whereas administration of exogenous testosterone to castrated males restored responsiveness, albeit not to the level observed in intact males. Administration of exogenous testosterone to intact female mice similarly enhanced responsiveness. Importantly, the promotive effects of exogenous testosterone in castrated male and intact female mice were absent when bilateral vagotomy was performed. Together, these data indicate that male sex hormones promote cholinergic airway responsiveness via a vagally mediated reflex mechanism that may be important in the regulation of airway tone in the normal and diseased lung.

scholarly journals Gender difference in the glucagon response to glucopenic stress in mice

2002 ◽  
Vol 282 (1) ◽  
pp. R281-R288 ◽  
Author(s):  
Sven Karlsson ◽  
Anton J. W. Scheurink ◽  
Bo Ahrén
Keyword(s):  
Gender Difference ◽  
Cell Mass ◽  
Plasma Catecholamine ◽  
Plasma Glucagon ◽  
Male Mice ◽  
Female Mice ◽  
Autonomic Activation ◽  
Catecholamine Response ◽  
Increased Sensitivity

A gender difference in the glucagon response to insulin-induced hypoglycemia was previously demonstrated in humans. Whether this reflects a gender difference in autonomic activation or in pancreatic α-cell regulation is not known. We investigated the glucagon, epinephrine, and norepinephrine responses to neuroglycopenic stress induced by 2-deoxy-d-glucose (2-DG) or insulin in female and male mice. 2-DG increased plasma glucagon levels by 559 ± 68% in females versus 281 ± 46% in males ( P< 0.01). Plasma levels of epinephrine or norepinephrine after 2-DG administration did not differ between genders. During insulin-induced hypoglycemia, the glucagon response was similarly higher in females ( P < 0.001), whereas the plasma catecholamine response was higher in males ( P < 0.05). In vivo, the glucagon response to carbachol or clonidine was higher in females ( P < 0.05). In isolated islets, the glucagon response to carbachol (100 μM; P = 0.003) but not to clonidine (1 μM) was larger in females. We conclude that in addition to a larger α-cell mass (previously described in female mice), an increased sensitivity of the glucagon-producing α-cell to cholinergic activation contributes to the larger glucagon response to glucopenic stress in female mice.

scholarly journals MOUSE COMPLEMENT: THE EFFECT OF SEX HORMONES AND CASTRATION ON TWO OF THE LATE-ACTING COMPONENTS

1967 ◽  
Vol 125 (4) ◽  
pp. 657-672 ◽  
Author(s):  
Winthrop H. Churchill ◽  
Ronald M. Weintraub ◽  
Tibor Borsos ◽  
Herbert J. Rapp
Keyword(s):  
Sex Hormones ◽  
Male Mice ◽  
Complement Components ◽  
Female Mice

The titer of late-acting complement components in sera from male mice is 8–10 times higher than the titer of sera from female mice. Using assays developed to measure the serum content of two of the late-acting components, we have shown that this difference is due to the effect of androgen and estrogen on these two late-acting complement components. These two components have been tentatively identified as C'5 and C'6. Androgen and estrogen have greater effect on C'6 than on C'5. The possibility has not been excluded that still other of the late-acting complement components are affected by androgens and estrogens. The course of homograft rejection was unchanged in mice deficient in C'5 and C'6.

scholarly journals Gonadotrope Plasticity at Cellular and Population Levels

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4729-4739 ◽  
Author(s):  
Zahara Alim ◽  
Cheryl Hartshorn ◽  
Oliver Mai ◽  
Iain Stitt ◽  
Colin Clay ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Ex Vivo ◽  
Single Cells ◽  
Anterior Pituitary Gland ◽  
Female Mice ◽  
Model Animal ◽  
Pituitary Glands ◽  
Acute Changes

Abstract Hormone-secreting cells within the anterior pituitary gland may form organized and interdigitated networks that adapt to changing endocrine conditions in different physiological contexts. For gonadotropes, this might reflect a strategy to cope with acute changes throughout different female reproductive stages. The current study examined gonadotropes in female mice at characteristically different hormonal stages: prepubertal, postpubertal, and lactating. Gonadotrope plasticity was examined at the level of the whole population and single cells at different stages by imaging both fixed and live pituitary slices. The use of a model animal providing for the identification of selectively fluorescent gonadotropes allowed the particular advantage of defining cellular plasticity specifically for gonadotropes. In vivo analyses of gonadotropes relative to vasculature showed significantly different gonadotrope distributions across physiological states. Video microscopy studies using live slices ex vivo demonstrated pituitary cell plasticity in the form of movements and protrusions in response to GnRH. As positive feedback from rising estradiol levels is important for priming the anterior pituitary gland for the LH surge, experiments provide evidence of estradiol effects on GnRH signaling in gonadotropes. The experiments presented herein provide new insight into potential plasticity of gonadotropes within the anterior pituitary glands of female mice.

scholarly journals An Exaggerated Immune Response in Female BALB/c Mice Controls Initial Toxoplasma gondii Multiplication but Increases Mortality and Morbidity Relative to Male Mice

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1154
Author(s):  
Rasha Alonaizan ◽  
Stuart Woods ◽  
Kerrie E Hargrave ◽  
Craig W. Roberts
Keyword(s):  
Immune Response ◽  
Imaging System ◽  
Acute Infection ◽  
Mortality Rates ◽  
Dependent Manner ◽  
Male Mice ◽  
Female Mice ◽  
Parasite Multiplication ◽  
Parasite Replication

Studies indicate that female mice are more susceptible to T. gondii infection, as defined by higher mortality rates in comparison to male mice. However, whether this is due to an inability to control initial parasite multiplication or due to detrimental effects of the immune system has not been determined. Therefore, the following studies were undertaken to determine the influence of sex on early parasite multiplication and the immune response during T. gondii infection and to correlate this with disease outcome. Early parasite replication was studied through applying an in vivo imaging system (IVIS) with luciferase expressing T. gondii. In parallel immunological events were studied by cytometric bead array to quantify key immunological mediators. The results confirmed the previous findings that female mice are more susceptible to acute infection, as determined by higher mortality rates and weight loss compared with males. However, conflicting with expectations, female mice had lower parasite burdens during the acute infection than male mice. Female mice also exhibited significantly increased production of Monocyte Chemoattractant Protein-1 (MCP-1), Interferon (IFN)-γ, and Tumour Necrosis Factor (TNF)-α than male mice. MCP-1 was found to be induced by T. gondii in a dose dependent manner suggesting that the observed increased levels detected in female mice was due to a host-mediated sex difference rather than due to parasite load. However, MCP-1 was not affected by physiological concentration of estrogen or testosterone, indicating that MCP-1 differences observed between the sexes in vivo are due to an as yet unidentified intermediary factor that in turn influences MCP-1 levels. These results suggest that a stronger immune response in female mice compared with male mice enhances their ability to control parasite replication but increases their morbidity and mortality.

The effects of repeated allergen challenge on airway smooth muscle structural and molecular remodeling in a rat model of allergic asthma

2009 ◽  
Vol 297 (4) ◽  
pp. L698-L705 ◽  
Author(s):  
Isabelle Labonté ◽  
Muhannad Hassan ◽  
Paul-André Risse ◽  
Kimitake Tsuchiya ◽  
Michel Laviolette ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Ex Vivo ◽  
Mrna Level ◽  
Allergen Challenge ◽  
Airway Responsiveness ◽  
Brown Norway ◽  
Contractile Phenotype ◽  
The Relationship

The effects of remodeling of airway smooth muscle (SM) by hyperplasia on airway SM contractility in vivo are poorly explored. The aim of this study was to investigate the relationship between allergen-induced airway SM hyperplasia and its contractile phenotype. Brown Norway rats were sensitized with ovalbumin (OVA) or saline on day 0 and then either OVA-challenged once on day 14 and killed 24 h later or OVA-challenged 3 times (on days 14, 19, and 24) and killed 2 or 7 days later. Changes in SM mass, expression of total myosin, SM myosin heavy chain fast isoform (SM-B) and myosin light chain kinase (MLCK), tracheal contractions ex vivo, and airway responsiveness to methacholine (MCh) in vivo were assessed. One day after a single OVA challenge, the number of SM cells positive for PCNA was greater than for control animals, whereas the SM mass, contractile phenotype, and tracheal contractility were unchanged. Two days after three challenges, SM mass and PCNA immunoreactive cells were increased (3- and 10-fold, respectively; P < 0.05), but airway responsiveness to MCh was unaffected. Lower expression in total myosin, SM-B, and MLCK was observed at the mRNA level ( P < 0.05), and total myosin and MLCK expression were lower at the protein level ( P < 0.05) after normalization for SM mass. Normalized tracheal SM force generation was also significantly lower 2 days after repeated challenges ( P < 0.05). Seven days after repeated challenges, features of remodeling were restored toward control levels. Allergen-induced hyperplasia of SM cells was associated with a loss of contractile phenotype, which was offset by the increase in mass.

scholarly journals The gain of smooth muscle's contractile capacity induced by tone on in vivo airway responsiveness in mice

2015 ◽  
Vol 118 (6) ◽  
pp. 692-698 ◽  
Author(s):  
Audrey Lee-Gosselin ◽  
David Gendron ◽  
Marie-Renée Blanchet ◽  
David Marsolais ◽  
Ynuk Bossé
Keyword(s):  
Airway Hyperresponsiveness ◽  
Ex Vivo ◽  
Airway Responsiveness ◽  
Control Group ◽  
Muscarinic Agonist ◽  
Mechanically Ventilated ◽  
Small Doses ◽  
Respiratory System Resistance ◽  
Experimental Group

Airway hyperresponsiveness to a spasmogenic challenge such as methacholine, and an increased baseline tone measured by the reversibility of airway obstruction with a bronchodilator, are two common features of asthma. However, whether the increased tone influences the degree of airway responsiveness to a spasmogen is unclear. Herein, we hypothesized that increased tone augments airway responsiveness in vivo by increasing the contractile capacity of airway smooth muscle (ASM). Anesthetized, tracheotomized, paralyzed, and mechanically ventilated mice were either exposed (experimental group) or not (control group) to tone for 20 min, which was elicited by nebulizing serial small doses of methacholine. Respiratory system resistance was monitored during this period and the peak response to a large cumulative dose of methacholine was then measured at the end of 20 min to assess and compare the level of airway responsiveness between groups. To confirm direct ASM involvement, the contractile capacity of excised murine tracheas was measured with and without preexposure to tone elicited by either methacholine or a thromboxane A2 mimetic (U46619). Distinct spasmogens were tested because the spasmogens liable for increased tone in asthma are likely to differ. The results indicate that preexposure to tone increases airway responsiveness in vivo by 126 ± 37% and increases the contractile capacity of excised tracheas ex vivo by 23 ± 4% for methacholine and 160 ± 63% for U46619. We conclude that an increased tone, regardless of whether it is elicited by a muscarinic agonist or a thromboxane A2 mimetic, may contribute to airway hyperresponsiveness by increasing the contractile capacity of ASM.

scholarly journals Cytochrome P450 Genes Are Differentially Expressed in Female and Male Hepatocyte Retinoid X Receptor α-Deficient Mice

Endocrinology ◽  
2003 ◽  
Vol 144 (6) ◽  
pp. 2311-2318 ◽  
Author(s):  
Yan Cai ◽  
Tiane Dai ◽  
Yan Ao ◽  
Tamiko Konishi ◽  
Kuang-Hsiang Chuang ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Negative Impact ◽  
Retinoid X Receptor ◽  
Differentially Expressed ◽  
Male Mice ◽  
Wild Type ◽  
Male And Female ◽  
Female Mice ◽  
Deficient Mice

Abstract To study the functional role of retinoid X receptor α (RXRα) in hepatocytes, hepatocyte RXRα-deficient mice have been established. Characterization has been performed on male mice. In this paper, we show that the expression of CYP450 genes is differentially expressed in male and female hepatocyte RXRα-deficient mice; male mice have reduced expression of cytochrome P450 (CYP) CYP4A, CYP3A, and CYP2B mRNAs, but females do not exhibit such phenotypes. To examine the hormonal effects on this sexual dimorphic phenotype, male and female mice were subjected to 17β-estradiol and 5α-dihydrotestosterone (DHT) treatment, respectively, and then the expression of the CYP450 genes was studied. Estradiol had no effect on protecting the hepatocyte RXRα-deficient mice from reduced expression of the CYP450 genes. In contrast, DHT induced hepatocyte RXRα-deficient female mice, but not wild-type female mice, to have the reduced expression of CYP450 mRNAs. In addition, castration prevented the mutant male mice from exhibiting reduced expression of CYP450 mRNAs. wild-type and mutant mouse livers from both genders express androgen receptors (ARs). By transient transfection, DHT-AR could inhibit RXRα-mediated transcription. Furthermore, by transfection and coimmunoprecipitation, RXR can interact with AR in vivo. These data suggest that testosterone has a negative impact on retinoid signaling when the level of RXRα is low, which may in turn reduce the expression of the CYP450 genes.

THE EFFECT OF GENISTEIN ON THE FERTILITY OF MICE

1955 ◽  
Vol 13 (1) ◽  
pp. 94-100 ◽  
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.

Extragonadal effects of luteinizing hormone in mice

1989 ◽  
Vol 121 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Kaoru Nomura ◽  
David W. Puett ◽  
David Puett ◽  
Kazuo Shizume ◽  
Grant W. Liddle
Keyword(s):  
Physiological Role ◽  
Male Mice ◽  
Intact Female ◽  
Intact Male ◽  
Kidney Weight ◽  
Kidney Size ◽  
Female Mice ◽  
Cellular Hypertrophy ◽  
Kidney Growth

Abstract. LH is composed of isoforms which exhibit microheterogeneity. We recently demonstrated that a particular ovine or porcine LH preparation (G100-fr.3) stimulates kidney growth. This study was conducted to clarify the physiological role of this renotropic activity and other extragonadal effects of the ovine LH preparation in CD-1 mice. Hypophysectomy caused a significantly greater reduction in relative dry kidney weight (i.e. g/100 g body weight) when compared to adrenalectomy, castration, thyroidectomy, and castration plus thyroidectomy. Supplementation with G100-fr.3 in these animals partially restored not only kidney size but also DNA, RNA and protein content. Treatment with standard LH preparations (NIDDKoLH24 and G3-268DA), as well as PRL, GH, FSH and TSH, failed to reverse the renal atrophy induced by hypophysectomy and castration. Administration of testosterone to castrated hypophysectomized mice increased kidney weight and RNA content, but not renal DNA. The relative dry kidney weight increased significantly at the onset of puberty in intact male mice, but not in castrated males or intact female mice. In addition, human CG increased kidney size in hypophysectomized male mice, but not in castrated hypophysectomized animals. These findings indicate that LH isoforms may regulate kidney growth in the male mouse both directly as a renotropin stimulating hyperplasia and indirectly as a gonadotropin via testicular androgen, producing cellular hypertrophy. It was also noted that G100-fr.3 decreased hepatic weight, DNA, RNA and protein, but produced no significant change in the spleen, heart or adrenal glands in castrated-hypophysectomized mice. Such extragonadal effects of G100-fr.3 were also observed in intact female mice. These results suggest that certain LH isoforms may have extragonadal actions involving the kidney and liver.

scholarly journals Acid exposure impairs mucus secretion and disrupts mucus transport in neonatal piglet airways

2019 ◽  
Author(s):  
Yan Shin J. Liao ◽  
Shin Ping Kuan ◽  
Maria V. Guevara ◽  
Emily N. Collins ◽  
Kalina R. Atanasova ◽  
...  
Keyword(s):  
Chloride Transport ◽  
Ex Vivo ◽  
Lavage Fluid ◽  
Mucus Secretion ◽  
Submucosal Gland ◽  
Cholinergic Stimulation ◽  
Diminazene Aceturate ◽  
Gland Duct ◽  
Airway Acidification

ABSTRACTTenacious mucus produced by tracheal and bronchial submucosal glands is a defining feature of cystic fibrosis (CF). Although airway acidification occurs early in CF, whether transient acidification is sufficient to initiate mucus abnormalities is unknown. We studied mucus secretion and mucus transport in piglets forty-eight hours following an intra-airway acid challenge. Acid-challenged piglet airways were distinguished by increased mucin 5B (MUC5B) in the submucosal gland but decreased lung lavage fluid MUC5B, following in vivo cholinergic stimulation, suggesting a failure in submucosal gland secretion. Concomitantly, intrapulmonary airways were obstructed with glycoprotein rich material under both basal and methacholine-stimulated conditions. To mimic a CF-like environment, we also studied mucus secretion and transport under diminished bicarbonate and chloride transport conditions ex vivo. Cholinergic stimulation in acid-challenged piglet airways induced extensive mucus films, greater mucus strand formation, increased dilation of submucosal gland duct openings and decreased mucociliary transport. Finally, to elucidate potential mediators of acid-induced mucus defects, we investigated diminazene aceturate, a small molecule that inhibits the acid-sensing ion channel (ASIC). Diminazene aceturate restored surface MUC5B in acid-challenged piglet airways under basal conditions, mitigated acid-induced airway obstruction, and magnified the number of dilated submucosal gland duct openings. These findings suggest that even transient airway acidification early in life might have profound impacts on mucus secretion and transport properties. Further they highlight diminazene aceturate as an agent that might be beneficial in alleviating certain mucus defects in CF airway disease.One sentence summaryEarly life airway acidification has profound impacts on mucus secretion and transport.

Sign in / Sign up

Export Citation Format

Share Document