bluuebunny/crossref_metadata_2025 huggingface dataset:
LOW‐LEVEL LASER THERAPY DECREASED THE NUMBER OF OVARIAN FOLLICULAR CYSTS IN POLYCYSTIC OVARIES‐INDUCED RATS
Authors: Alves Eduardo Donato , de Oliveira Bonfá Ana Lúcia , Pigatto Glauce Regina , Achcar Jorge Alberto , Parizotto Nivaldo Antonio , Montrezor Luís Henrique
Published: June 2021

Female rats induced to polycystic ovary (PCO) present ovarian alterations in both folliculogenesis and steroidogenesis. There are a reductions in the numbers of follicles and corpora lutea, in addition to the appearance of follicular cysts. Hyperandrogenemia is a consequence of steroidogenic alterations that induce irregular estral cycles and folliculogenesis. Low‐level laser therapy (LLLT) and light‐emitting diode (LEDs) therapy have been investigated and used in clinical practice concernig the biomodulation of cellular functions both in vivo and in vitro. The objective of this study was to analyze the effects of LLLT on the number of ovarian follicular cysts in PCO rats. Forty‐five female adult Wistar rats weighing 250–300 g were divided into control (n = 15), PCO (n = 15) and PCO/laser (n = 15) groups. PCO in the rats was induced by single injection of estradiol valerate (EV) (2 mg/kg/bw, i.m.). After PCO induction, the rats were divided into groups evaluated 30, 45, and 60 days after the injections. The animals were manually contained and irradiated with a laser (wavelength 808 nm, power 60 mW) using a dose of 3 Joules(J)/point for 18 seconds on the dorsal region, performing a transillumination on each ovary 3 times a week, totaling 6 J of energy per irradiated animal/per day of application. After sacrifice, the ovaries were collected for preparation and subsequent analysis of histological slides. The results were reported as means ± SEM. Statistically significant differences among the means for the treatment groups were identified using p<0.05. This study was approved by the local Animal Care and Use Committee (CEUA–UNIARA, protocol n° 019/16). The findings showed that the highest number of follicular cysts (6.33 ± 1.52) occurred in the PCO group 60 days after EV injection, while the lowest number of follicular cysts was observed in the control group (0.33 ± 0.57). The PCO animals submitted to LLLT for 60 days presented fewer (3 ± 1) follicular cysts than the PCO animals, but more follicular cysts than the control animals. The highest number of follicles was observed in the control group after 30 days (8 ± 1), while the lowest number was observed in the PCO group after 60 days (1.66 ± 0.57). The number of follicles found for the 60‐days PCO/laser group (6.66 ± 0.57) was higher than for the PCO group and equal to the control group. It could be concluded that the use of LLLT decreased the number of follicular cysts and increased the number of ovarian follicles in the PCO/laser group, compared to the PCO group, apparently restoring the ovarian folliculogenesis activity.

Support or Funding Information

Grant #2016/02811‐4. São Paulo Research Foundation (FAPESP).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Early gestational exposure to ozone increases caloric consumption in male and female peri‐adolescent offspring when challenged with a high fat diet
Authors: Miller Colette N. , Stewart Erica , McDaniel Katherine L. , Phillips Pamela M. , Schladweiler Mette C. , Richards Judy H. , Valdez Matthew , Gordon Christopher J. , Kodavanti Urmila P. , Dye Janice A.
Published: June 2021

Offspring that are growth restricted at birth have increased risk of infant mortality and cardiometabolic disease as they mature. We have previously demonstrated that acute exposure to the air pollutant, ozone, in early pregnancy results in reduced fetal growth. Utilizing this same model, we sought to explore the risk of obesity in early adulthood in offspring that were prenatally exposed to ozone during implantation. Pregnant, Long‐Evans rats were exposed to filtered air or 0.8 ppm ozone, 4 hours/day on gestational day 5 and 6. Peri‐adolescent (~post‐natal day, PND, 45) male and female offspring from the aforementioned dams were fed either a 10% low‐fat diet (LFD) or 45% high‐fat diet (HFD) for 72 hours. Food intake, body weight gain, and changes in body composition were monitored during this time period. Basal metabolic rate was determined for the final 24 hours of the diet challenge. At birth, offspring from ozone‐exposed pregnancies were approximately 4–7% smaller than control litters. By PND 4, males from ozone pregnancies caught up in weight to that of control males, and by PND 34 had become heavier than controls (~4%). Female offspring from ozone pregnancies remained smaller than control females until ~PND 22. A significant effect of prenatal ozone exposure was found in both grams and calories consumed over 72 hours in male and female offspring. When both sexes were challenged with a HFD, rats from ozone‐exposed pregnancies consumed more calories than LFD‐fed rats (~30% kcal increase). Although increased caloric consumption did not increase body weight gain in either sex of the ozone‐exposed offspring, males of the ozone‐exposed, HFD‐group had increased fat deposition over the 72‐hour period compared to both LFD‐fed groups (~290% increase). Measurement of basal metabolic rate indicated that all rats increased fat metabolism, without an effect of prenatal ozone exposure, when fed a 72‐hour HFD. However, a significant effect of prenatal ozone to reduce metabolic rate during the light cycle was observed in female offspring. Taken together, these data suggest that ozone exposure early in gestation disrupted energy balance in adolescence. Because both food intake and metabolic rate are regulated within the hypothalamus, we postulate that the prenatal growth restriction observed in our model was associated with disrupted hypothalamic development. Moreover, the increase in caloric intake observed in ozone‐exposed offspring may serve to increase the risk of obesity, particularly in males. This abstract does not reflect U.S. EPA policy.

Support or Funding Information

This research was funded by the U.S. EPA.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Cervical Sympathetic Chain Stimulation on Upper Airway Pressure is Dependent on Direct Post‐Ganglionic Innervation from the Superior Cervical Ganglion
Authors: Hassan Sarah F. , Zenebe Woineshet J. , Lewis Stephen J. , Hsieh Yee‐Hsee Hsee
Published: June 2021

BACKGROUND

We have previously demonstrated that cervical sympathetic chain (CSC) stimulation improves airway patency in Zucker Fat rats (model of concentric airway collapse). Anatomical studies reveal the presence of two major post‐ganglionic projections to the head and neck arising from the superior cervical ganglion (External Carotid Nerve (ECN) and Internal Carotid Nerve (ICN)), however, their functional contribution to improve upper airway patency is unclear.

AIM

We sought to investigate the contribution of the CSC‐SCG‐ECN and CSC‐SCG‐ICN pathways on lowering upper airway pressure (UAP) and cardiorespiratory systems.

METHODS

Urethane‐anaesthetized healthy male Sprague‐Dawley (SD) rats and pathological Zucker Fat (ZF) rats were used to measure UAP, ECG, blood pressure and diaphragmatic EMG while the intact CSC was stimulated (bilaterally and unilaterally). CSC stimulation mediated effects on UAP and cardiorespiratory parameters were then assessed following systematic transection of ECN and ICN branches.

RESULTS

We present two novel findings. Firstly, in all cases of CSC stimulation (SD control UAP (mmHg): −27% bilateral, −20% right, −6% left; ZF control UAP (mmHg): −34% bilateral, −19% right, −22% left), ECN denervation had no significant effect on UAP reductions or hemodynamics in both healthy and disease rats. Secondly, bilateral denervation of the ICN abolished CSC mediated UAP reductions, while leaving hemodynamic effects intact. UAP mediated effects via unilateral CSC stimulation were of ipsilateral origin, as contralateral ICN denervation prior to ipsilateral denervation had no effect. Little to no impact of laterality of CSC stimulation and ICN transection was seen in hemodynamics or diaphragmatic EMG.

CONCLUSION

For the first time, we have demonstrated that CSC stimulation reductions on upper airway pressure are dependent on ipsilateral post‐ganglionic innervation via the ICN. However, the lack of effect on hemodynamics remains to be defined.

Support or Funding Information

NIH1OT2OD023860‐01, Galvani Bioelectronics

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Extracellular and Intracellular Dehydration Affect Urinary Bladder Reactivity to Vasopressin and Neurotransmitters of the Autonomic Nervous System in Anesthetized Female Wistar Rats.
Authors: Cafarchio Eduardo Mazuco , Vale Bárbara , da Silva Daniel Santana , da Silva Luiz Augusto , Faccini Cristiane , Fonseca Fernando Affonso , Maifrino Laura Beatriz Mesiano , Sato Monica Akemi
Published: June 2021

Background

The effects of extracellular dehydration on the urinary bladder reactivity.

Aim

To investigate if different extracellular dehydration models affect urinary bladder reactivity to vasopressin and neurotransmitters of the autonomic nervous system in female Wistar rats.

Methods

Adult female Wistar rats (N=6/group) one group the animals were in water deprivation for 24 hours and another group received a furosemide injection (50,0 mg/Kg S.C) and were maintained with sodium free diet. After all animals were anesthetized with 2% isoflurane in 100% O2 underwent to a cannulation of the femoral artery for mean arterial pressure and heart rate recordings. The urinary bladder was cannulated for intravesical pressure (IP) recordings. After baseline recording of the physiological parameters for 15 min, drugs (vasopressin 1 ng/mL, or acetylcholine 2 ug/mL, or noradrenaline 2 ug/mL) were administrated in situ (0.1 mL) on the urinary bladder and all the parameters were recorded for the control responses The AVP receptor subtypes were also labeled by immunofluorescence technique in the urinary bladder. Data are as mean±SE and were submitted to paired Student t‐test (p<0.001).

Results

The water privation group responses in IP to vasopressin (39,5±1,0% vs. 110,1±1,9% control), acetylcholine (125,9±12,4% vs. 488,8±24,9% control), and noradrenaline (−17,5±1,0% vs. −67,6±1,6% control) were attenuated. Similarly the furosemide group the IP responses to vasopressin (42,8±2,8% vs. 110,1±1,9% control), acetylcholine (145,0±5,0% vs. 488,8±24,9% control), and noradrenaline (−28,8±1,0% vs. −67,6±1,6% control)were reduced. The immunofluorescence was showed a decrease in the amount of vasopressin receptors on the membrane of urinary bladder cells after dehydration in both models.

Conclusion

Both models decreased the urinary bladder reactivity to vasopressin and to the neurotransmitters released by the autonomic nervous system innervation on the urinary bladder.

Support or Funding Information

Financial Support: FAPESP, CAPES and NEPAS.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Iliocapsularis and Long Head of Triceps Brachii Innervation: Not Such “Textbook” Cases
Authors: Breckling Abbey , Jonees Michael W. , Ferrigno Christopher
Published: June 2021

Anatomy instructors rely on accurate anatomical texts to facilitate instruction. While the understanding of anatomy continues to evolve, recent advancements are most reliably reflected in the vast amount of peer‐reviewed literature (PRL). Adjustments in anatomy textbooks (TBs), however, may take years to occur due to the publishing constraints such as illustrations and content vetting procedures. Consequently, TBs tend to lag behind the PRL with respect to new content. Subsequently, anatomy instruction may be dated despite the well‐intentioned instructor. Here we highlight two musculoskeletal‐focused discrepancies in anatomical PRL and TB literature: the presence of the Iliocapsularis (IC) and the innervation of the Long Head of Triceps Brachii (LHTB). To explore potential discrepancies, we used convenience sampling and audited 16 widely‐used TBs published within the past 10 years (3.1 ± 2.8 years) to determine the presence of IC and the innervation of the LHTB. We also analyzed PRL published within the past 18 years (5.4 ± 6.7 years) which focused on studies that used MRI or dissection to determine the presence of IC, and dissection only to explore the innervation of LHTB to the triceps. We conducted human dissection to verify the literature audit findings. To better evaluate the presence of IC, we dissected 22 anterior hips on preserved limbs in 11 cadavers and 5 unpreserved limbs in 3 cadavers. To better assess the innervation of the LHTB, we dissected the posterior shoulder and arm on 5 preserved limbs in 5 cadavers and 3 unpreserved limbs in 3 cadavers, with the aim of completing LHTB dissections on a minimum of 20 limbs. Out of 16 TBs reviewed, only 1 suggested the presence of IC and all reported the radial nerve as the innervation of LHTB (Table 1). Conversely, 4 PRL studies used dissection or MRI to assess the presence of IC and 3 studies used dissection to assess the innervation of LHTB by nerves other than the radial nerve (namely the axillary nerve) (Table 2). When pooling the individuals assessed in PRL, 100% were found to have an IC (n=271) and 72.2% were found to have a LHTB innervated by the axillary nerve. Our dissections of the anterior hips revealed that the IC was present in 100% of the 27 limbs. Our dissections of the posterior shoulder and arm revealed that the axillary nerve innervated the LHTB in 50% of the 8 bodies, including 2 of the 5 preserved limbs and 2 of the 3 unpreserved limbs. This study demonstrates that recently published TBs are not in alignment with the anatomical findings of our dissections or, more importantly, with the PRL. These findings suggest that anatomist instructors, as well as clinicians, should be familiar with recently published PRL and not rely solely on anatomical TBs.

Support or Funding Information

None

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Identification of Rapid Autonomic Adjustments Following Exercise at Onset of Isolated Post‐Exercise Muscle Metaboreflex Activation Using Continuous Wavelet Transform of Heart Rate Variability in Healthy Young Adults
Authors: Drew Rachel C. , Sánchez‐Hechavarría Miguel E. , Carrazana‐Escalona Ramón , Blaha Cheryl A. , Sinoway Lawrence I.
Published: June 2021

Immediately following cessation of exercise, central command and muscle mechanoreflex inputs are removed but muscle metaboreflex input can remain in certain situations. Continuous wavelet transform allows analysis of heart rate variability (HRV) at times of rapid autonomic adjustments. However, it is unknown whether CWT can identify the rapid autonomic adjustments that occur immediately following cessation of exercise at the onset of isolated post‐exercise muscle metaboreflex activation. Therefore, we retrospectively applied CWT analysis to data previously collected from 14 healthy young adults (8 women/6 men; mean ± SD age 26 ± 2y) who performed one‐legged, isometric, calf exercise at 70% maximal voluntary contraction for 1.5 minutes, followed by circulatory occlusion via cuff inflation around the exercising limb that was maintained for 30 seconds to isolate muscle metaboreflex activation immediately post‐exercise. CWT analysis of R‐R intervals (electrocardiogram) included log‐transformed absolute and normalized low‐frequency (LF; 0.04–0.15Hz) and high‐frequency (HF; 0.15–0.4Hz) time‐frequency bands and the ratio of LF/HF for each of the six 5‐s time windows during the 30‐s muscle metaboreflex activation. Statistical analysis involved one‐way repeated measures analysis of variance with posthoc analysis. Absolute and normalized HF during 16–20s, 21–25s, and 26–30s following end‐exercise (4.73 ± 1.18, 4.90 ± 1.22, and 4.81 ± 1.10ms2, and 12.85 ± 10.37, 15.80 ± 12.04, and 14.99 ± 11.36 normalized units (nu), respectively) were higher than 1–5s following end‐exercise (3.6 ± 1.13ms2 and 5.01 ± 4.51nu, respectively; P < 0.05). Absolute LF was not different across time‐points (P < 0.05), but normalized LF during 16–20s, 21–25s, and 26–30s following end‐exercise (87.15 ± 10.37, 84.20 ± 12.04, and 85.01 ± 11.36nu) was lower than 1–5s and 6–10s following end‐exercise (94.99 ± 4.51 and 94.23 ± 4.44nu; P < 0.05). LF/HF during 11–15s, 16–20s, 21–25s, and 26–30s following end‐exercise (2.59 ± 0.80, 2.24 ± 0.97, 1.97 ± 1.00, and 1.99 ± 0.91) was lower than 1–5s following end‐exercise (3.32 ± 0.97; P < 0.05). In conclusion, CWT can identify the restoration of parasympathetic modulation of HRV and/or reduction in sympathetic modulation of HRV during the onset of isolated post‐exercise muscle metaboreflex activation in healthy young adults.

Support or Funding Information

Supported by National Institutes of Health grants UL1 TR000127 and P01 HL096570.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hypoxia‐Induced Ubiquitination Regulates 14‐3‐3η‐Gremlin‐1 Interactions in a Hypoxia Model of Pulmonary Hypertension.
Authors: Wade Brandy E. , Zhao Jingru , Ma Jing , Hart C. Michael , Sutliff Roy L.
Published: June 2021

Pulmonary Hypertension (PH) is characterized by increased pulmonary artery pressure andresistance, right ventricle (RV) hypertrophy, RV failure and death. Increased vascular cell proliferation and vascularremodeling contribute to PH progression, though the mechanisms are incompletelydefined. The ubiquitin proteasome system (UPS)regulates cellular homeostasis through post‐translational modification oftarget proteins with ubiquitin moieties that direct protein degradation, protein‐proteininteractions, activity, or localization. Massspectrometry analysis of lungs from mice exposed to normoxia or hypoxia,revealed hypoxia‐induced changes in protein ubiquitination. Hypoxia caused a 2.4‐fold increase inubiquitination of 14‐3‐3eta (14‐3‐3η) at lysine (K)50 (p<0.05) with no change in 14‐3‐3η protein levels. Dysregulation ofthe 14‐3‐3 family of binding proteins is known to promote tumor cellproliferation and migration pathways. We hypothesized that 14‐3‐3η K50 ubiquitinationmay change protein activity since K49/50 is known to play an important role in14‐3‐3 function. K50 is also near the binding site for Gremlin‐1, a proteinthat promotes proliferation by inhibiting bonemorphogenetic protein (BMP)signaling. Immunoprecipitation of 14‐3‐3η from hypoxia‐exposed mouse lungdemonstrated that hypoxia reduced binding of 14‐3‐3η to Gremlin‐1. IncreasedGremlin‐1 to BMP2 binding was also observed in hypoxia‐exposed mouse lungs,suggesting that Gremlin‐1/BMP2 binding may contribute to disrupted BMPsignaling previously observed in hypoxia. Expression of a lysine to argininemutation at 14‐3‐3η K50 (K50R) whichprevents ubiquitination of K50 without altering the local polarity or shape inhuman pulmonary artery endothelial cells, promotes 14‐3‐3η/Gremlin‐1interaction in hypoxia. These findings demonstrate that K50 ubiquitination regulates14‐3‐3η function and its interaction with Gremlin‐1. We speculate thathypoxia‐induced increases in 14‐3‐3η K50 ubiquitination reduce Gremlin‐1 bindingwhich in turn binds BMP ligands to reduce BMP signaling and thereby promote vascularcell proliferation and PH pathogenesis.

Support or Funding Information

Merit Review funding from the Department of Veterans Affairs, Office ofResearch and Development 1I01BX001910 (CMH), NIH Grant RO1HL102167 (CMH and RLS), NIH T32 HL076118 and 16POST30930007 (BEW). MS work was performed by the Emory Integrated Proteomics Core

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Airway mechanoreceptors that control breathing
Authors: Chang Rui , Strochlic David , Nonomura Keiko , Patapoutian Ardem , Liberles Stephen
Published: June 2021

The airways contain a myriad of sensory cells that mediate olfaction, control breathing, and protect the respiratory system from damage and disease. The vagus nerve is a major conduit between lung and brain required for normal respiration, and some vagal sensory neurons detect airway expansion that occurs with every breath. Mechanical inflation of the lungs and airways triggers a protective respiratory reflex termed the Hering‐Breuer inspiratory reflex, characterized by acute apnea. How vagal sensory neurons detect increases in airway volume was unknown at a molecular level. We initiated a molecular and genetic analysis of the sensory vagus nerve, identifying cell types that innervate the lung and powerfully control breathing. Moreover, we identified a critical role for the ion channel Piezo2 in airway mechanoreception. Optogenetic activation of vagal afferents containing Piezo2 causes apnea, trapping animals in a state of exhalation. Moreover, conditional deletion of Piezo2 from nodose ganglion‐derived sensory neurons eliminates sensory neuron responses to airway stretch as well as the classical Hering‐Breuer inspiratory reflex. These findings indicate a key role for Piezo2 as an airway stretch sensor critical for establishing efficient respiration at birth and maintaining respiratory homeostasis in adults. Understanding the sensory biology of respiratory control neurons in the vagus nerve may provide therapeutic targets for airway disease intervention.

Support or Funding Information

Harvard‐MIT Joint Research Grants Program in Basic Neuroscience to S.D.L, R01DE022358 to A.P. and R01HL132255, and a Giovanni Armenise‐Harvard Foundation Grant to S.D.L. A.P. is an investigator of the Howard Hughes Medical Institute.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Disinhibition of Bötzinger Complex Abolishes Active Expiration Induced by Sustained Hypoxia in Rats
Authors: Zoccal Daniel B. , Amarante Marlusa K. , Flor Karine C.
Published: June 2021

Exposure to sustained hypoxia, as experienced in high altitudes, elicits an increase in baseline ventilation that persists upon reoxygenation. We previously demonstrated that the increased baseline ventilation induced by short‐term sustained hypoxia (SH, 10% O2 for 24 hs) in rats is associated with the emergence of active expiration. However, the neural mechanisms underlying this respiratory pattern modification in SH rats remain unknown. In the present study, we hypothesized that alterations in the Bötzinger complex (BötC) activity, an important inhibitory region of the respiratory network, play a role in the generation of active expiration in SH rats under resting conditions. Using the decerebrated, arterially perfused in situ preparation of rats previously exposed to normoxia (control) or SH, we pharmacologically manipulated the activity of BötC as well as evaluated the activity of expiratory neurons in this region while recorded the activity of phrenic (PN), central vagus (cVN) and abdominal nerves (AbN). The in situ preparations of SH rats (n=8) exhibited augmented baseline abdominal activity, with the emergence of additional bursts during late phase of expiration, which were not seen in controls (n=8, P<0.05). Disinhibition of the BötC, with bilateral microinjections of strychnine (glycine receptor antagonist, 10 μM, 30–40 nl/side), eliminated the active expiratory bursts in the AbN activity and restored the eupneic‐like respiratory pattern in SH rat preparations (n=8, P<0.05). Bilateral microinjections of strychnine in the BötC of control preparations (n=7) caused small reductions in all nerve amplitudes (P<0.05), without disrupting the 3‐phase respiratory pattern. We also found that the BötC post‐inspiratory (post‐I) neurons in SH preparations (n=2) exhibited an earlier shut down during the expiratory phase compared control group (n=3, P<0.05), which was coincident with the emergence of AbN expiratory bursts. In contrast, the BötC augmenting‐expiratory neurons (aug‐E) of SH preparations (n=3) exhibited an anticipated onset in comparison to the aug‐E activity of control preparations (n=2, P<0.05). Altogether, our data indicate that the neurons of the BötC exert an inhibitory control on the mechanisms underpinning the pattern of active expiration in SH rats. Based on our neuronal recordings, we speculate that this inhibitory control of the BötC might be driven by the post‐I population.

Support or Funding Information

FAPESP (2013/17.251‐6; 2015/23568‐8)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Ventilatory CO2/H+ Chemoreflex During Chronic Hypercapnia in Healthy Goats
Authors: Burgraff Nicholas , Buchholz Kirstyn , Neumueller Suzanne , Hodges Matthew , Pan Lawrence , Langer Thomas , Forster Hubert
Published: June 2021

Respiratory disease patients that hypoventilate and develop chronic hypercapnia often show poorer prognoses, decreased quality of life, and higher mortality rates compared to similar disease patients that maintain pulmonary ventilation and arterial CO2. Herein, we sought to determine the effect of chronic hypercapnia on the temporal pattern of the acute ventilatory and diaphragmatic EMG responses to increasing PaCO2 by exposing goats to either room air or an elevated inspired CO2 (InCO2) to 6% for up to 15 days. On several days, InCO2 was further increased to 7 and then 8% to assess ventilatory and diaphragmatic EMG responses. CO‐2 sensitivity (ΔVI‐/ΔPaCO2) progressively declined during the first 5 days of hypercapnia, reaching a nadir of 31% below control on day 5 of hypercapnia. Similar declines during the first 5 days of chronic hypercapnia were observed in the tidal volume (VT), breathing frequency (f), integrated diaphragmatic EMG (Dia EMG), ventilatory drive (VT/TI), and peak inspiratory flow responses as a function of PaCO2 during acute elevations to 7 and 8% InCO2 ranging from 39–62% below control by day 5. Following the initial decline in responses, there was a recovery of the VI, VT, f, Dia EMG, VT/TI, and peak inspiratory flow responses to control levels between days 8–15. The V‐I−/H+ relationship during acute increases to 8% InCO2 remained unchanged over the 15 days. However, VI/H+ at 6% InCO2 was ~200% above control from 2–15 days of chronic hypercapnia, suggesting a disconnect between the chronic VI/H+ relationship at 6% InCO2 and the VI−/H+ relationship during acute elevations to 8% InCO−2. The relationship between inspiratory flow and diaphragm EMG activity decreased to 69% of control by day 2 of hypercapnia, followed by a sustained increase to 149–248% above control thereafter, indicative of further respiratory muscle recruitment or increased dilatory effects on the airways. In summary, we have established a model to determine the effects of chronic hypercapnia on the temporal pattern of ventilatory CO−2/H+ sensitivity. Results from this study may provide insight into the role of hypercapnia in the progression of respiratory disease adaptation.

Support or Funding Information

‐Department of Veteran Affairs; NIH HL007852

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Acute and Chronic Respiratory Effects from Repeated Audiogenic Seizures in SSKcnj16−/− Rats
Authors: Manis Anna D. , Mouradian Gary C. , Alvarez‐Argote Santiago , Staruschenko Alexander , Palygin Oleg , Hodges Matthew R.
Published: June 2021

Kir5.1 is a member of an inwardly rectifying potassium (Kir) channel family highly expressed in the kidney and brain. Mutations in ion channel genes can alter neuronal excitability, and mutations in related Kir genes have been linked to seizure disorders in humans. We previously established that a knockout rat model of Kcnj16 (gene encoding Kir5.1) on a Dahl salt‐sensitive background (SSKcnj16−/−) exhibits a severe cardiovascular phenotype (Palygin et al., JCI Insight, 2017) as well as an audiogenic reflex epilepsy phenotype. SSKcnj16−/− rats, but not control SS rats, experience tonic‐clonic seizures when exposed to a 10 kHz tone (86 dB for 2 min). Although seizures are typically considered benign events, patients with uncontrolled epilepsy are 27 times more likely die of Sudden Unexplained Death in Epilepsy (SUDEP) compared to those without epilepsy, presumably due to cardiorespiratory failure associated with repeated seizures. Here, we tested the hypothesis that repeated audiogenic seizures would acutely and chronically alter breathing in SSKcnj16−/− but not control SS rats. SSKcnj16−/− and control rats were exposed to the acoustic stimulus once/day for 10 days while using plethysmography to measure breathing before, during, and after exposure. SSKcnj16−/− rats show a marked increase in tidal volume (1.4 ± 0.1 to 3.2 ± 1.2 mL/100g) after acoustic stimulation which becomes more pronounced after exposure to 10 acoustic stimuli (1.7 ± 0.1 to 4.2 ± 1.1 mL/100g). Minute ventilation and drive to breathe show similar increases with successive acoustic exposures. SS control rats do not show changes in tidal volume or minute ventilation over the 10 days. In addition, we see a substantial increase in resting VO2 between day 1 (7.4 ± 0.4 mL/min/100g) and day 10 (11.8 ± 0.6 mL/min/100g) of acoustic stimulation in SSKcnj16−/−/− rats but not controls. During the 10 days of stimulation, we observed spontaneous mortality in 33% of SSKcnj16−/− rats (N = 7 of 21 total) within hours of a seizure, while 100% (N=12) of control SS rats survived. We found no difference among male and female SSKcnj16−/− rats, where both sexes had a similar audiogenic seizure response and reduced survival. Further studies into the mechanisms behind seizure‐induced death in SSKcnj16−/− rats could have central relevance to the pathophysiology of SUDEP, which remains poorly understood.

Support or Funding Information

NIH HL122358

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Central and Peripheral Respiratory Disturbances in a Mice Model of Parkinson's Disease
Authors: Oliveira Luiz M. , Oliveira Maria A. , Moriya Henrique T. , Moreira Thiago S. , Takakura Ana C.
Published: June 2021

Parkinson's disease (PD) is a neurodegenerative motor disorder characterized by dopaminergic deficits in the brain. PD patients may experience shortness of breath, dyspnea and breathing difficulty. Breathing abnormalities have been recognized as a cause of morbidity and mortality of PD patients. It is well known that PD patients have a predisposition to develop pneumonia, embolism and allergic reactions compared to general population. However, it's not clear if an animal model of PD could develop lung properties changes. The aim of the present study is to confirm the role of neurodegenerative processes in brainstem regions involved in breathing control and to investigate lung properties in a mouse model of PD. Experiments were performed in adult male C57BL/6 mice (20–25 g, N = 14). The animals received bilateral injection of 6‐hydroxydopamine hydrochloride (6‐OHDA; 10 μg/μL; 0.5 μL) or vehicle into the striatum. The ventilatory parameters were assessed by whole body plethysmograph and measurements of respiratory mechanics by a mouse ventilator (flexiVent) 40 days after PD induction. 6‐OHDA reduced the number of tyrosine hydroxilase (TH+) neurons in the SNpc 40 days after the toxin injection. No changes in TH+ were observed in C1 and Locus coeruleus regions in PD mice. We also noticed a reduction in the immunoreactivity of neurokinin‐1 receptors (NK1R) in the pre‐Bötzinger complex (preBötC) and in the number of Phox2b neurons in the retrotrapezoid nucleus (RTN). Physiological experiments were conducted in the same animals. Resting respiratory frequency (fR) in PD animals was reduced (156.3 ± 3.4 vs. control: 176.1 ± 3.5 breaths/min) leading to an increase of expiratory time (TE) (0.36 ± 0.02 vs. control: 0.28 ± 0.03 ms). In respect to mechanical properties, PD animals with preserved thorax elicited an increase in airway resistance (0.33 ± 0.02 vs. control: 0.27 ± 0.01 cmH2O.s/ml) and elastance (31.3 ± 2.1 vs. control: 25.3 ± 0.6 cmH2O/ml, p<0.019). However, after open the thorax, PD animals did not show changes in airway resistance, but still have an increase in elastance (30.8 ± 2.1 vs. control: 24.0 ± 1.4 cmH2O/ml, p<0.017), indicating that the ribcage could be stiffened in PD. PD animals presented collagen deposition in alveolar septa (18.3 ± 1.5 vs. control: 12.5 ± 1.4 %). Our data showed that PD animals presented neurodegeneration in respiratory brainstem areas and a disruption of lung properties, suggesting that central and peripheral deficiencies can contribute to the respiratory changes observed in this model.

Support or Funding Information

FAPESP, CNPq, CAPES/PROEX

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cystic Fibrosis Transmembrane Conductance Regulator Regulates Pannexin 1 Channel Opening for Acidosis‐induced ATP Release from Cardiomyocytes
Authors: wang yongshun , Ballard Heather Janet
Published: June 2021

ATP is released in the heart under a variety of conditions, including hypoxia, ischaemia and catecholamine stimulation. Under physiological conditions, extracellular ATP, and its breakdown product, adenosine, contribute to local vasodilation and regulation of coronary blood flow. We investigated the mechanism of ATP release in cardiomyocytes isolated from adult rat heart.

Treatment with lactic acid produced pH depression and enhanced ATP release from cardiomyocytes. On the other hand, simulated ischaemia (metabolic inhibition plus anoxia) lowered ATP release. The acidosis‐induced ATP release was abolished by the specific CFTR inhibitor, CFTRinh‐172, CFTR pore blocker, GlyH‐101, or CFTR siRNA, suggesting that CFTR was involved. Forskolin and IBMX, agents that activate CFTR by elevating the intracellular cAMP, also increased ATP release, confirming the role of CFTR. However, blockade of Pannexin1 channels by Fast Green FCF, Brilliant Blue FCF, or pannexin1 siRNA, attenuated the ATP release during acidosis or forskolin treatment, and further lowered the ATP release during simulated ischaemia, suggesting that Pannexin1 functions as the ATP release channel. Immunofluorescence imaging suggested that CFTR and Pannexin1 were not co‐localized. Inhibition of either the Na+/H+ exchanger (NHE) with amiloride or the Na+/Ca2+ exchanger (NCX) with SN6 or KB‐R7943 abolished acidosis‐induced ATP release. FAK inhibitor 14, FAK autophosphorylation inhibitor, can attenuate the forskolin or lactic‐acid‐stimulated ATP release. Furthermore, forskolin or lactic‐acid‐stimulated ATP release was abolished by bicarbonate free medium or caspase inhibitor. Thus, we have demonstrated that the acidosis‐induced ATP release was involved in calcium induced CFTR open. The cyclic AMP, which activates mitochondrial PKA, is generated within mitochondria by the bicarbonate‐regulated soluble adenylyl cyclase (sAC). Hence, we propose that the CFTR Cl channel opens during acidosis, allowing the movement of bicarbonate into the cell, which activate the HCO3‐sAC‐cAMP‐PKA (mito‐sAC) signaling cascade and indirectly modulates Pannexin1 gating by activation of caspase.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Glypican‐1 Mediates Endothelial Hyper‐permeability in a Model of Acute Heart Failure
Authors: Chignalia Andreia , Isbatan Ayman , Patel Milan , Borlaug Barry , Dull Randal
Published: June 2021

Accumulating evidence indicates that the lungs are active participants in the pathogenesis of heart failure (HF). Increases in left ventricular end diastolic pressure (LVEDP) leads to elevated pulmonary capillary pressure (PCP) that causes fluid filtration resulting in dyspnea and, ultimately, frank pulmonary edema (PE). However, the severity of dyspnea does not directly relate to the increase in PCP indicating that the clinical manifestation of HF cannot be solely explained by changes in Starling forces. Acute increases in PCP activate glycocalyx‐dependent signaling (endothelial mechanotransduction) that result in oxidative stress, eNOS activation and endothelial hyper‐permeability. Herein we sought to investigate if glypican‐1, a component of the glycocalyx, contributes to pressure‐dependent hyper‐permeability and PE in a model of acute HF. The isolated perfused lung preparation was used to simulate acute HF in male CD‐1 (wild type, WT) and glypican‐1 knockout (Gpc‐1 KO) mice (6 weeks old). Briefly, mice were anesthetized with isoflurane, tracheostomized and mechanically ventilated. Pulmonary artery and left atria were cannulated and in‐line pressure transducers recorded arterial and left atrial pressure; lungs were perfused at 2 mL/min with a Krebs‐Ringer 3% BSA buffer. Control experiments were done setting left atria pressure (PLA) at 3 cm H2O for 10 minutes; acute heart failure was simulated by setting PLA at 10 cm H2O for 10 minutes. Lung edema was assessed by lung wet‐to‐dry ratio; reactive oxygen species (ROS) production and eNOS activation were assessed as indices of mechanotransduction activation by lucigenin enhanced chemiluminescence and immunoblotting, respectively. NADPH oxidase activity was measured by dihydroethidium fluorescence in isolated membrane‐fracions. WT and Gpc‐1 KO mice had similar increase in pulmonary artery pressure (from 8 to 10 mmHg). Deletion of glypican‐1 protected mice from pressure‐induced PE (wet‐to dry ratio [high and low pressure, respectfully] in WT: 7.3±0.3 vs 4.9±0.3 and in Gpc‐1 KO: 4.8±0.3 vs 4.8±0.2), prevented pressure‐dependen increase in NADPH oxidase activity (15% increase in WT) and in ROS production (80% increase in WT). Moreover, while WT mice showed increased eNOS activation (2‐fold) during acute HF, Gpc‐1 KO mice showed reduced eNOS activation (0.5 fold) indicating that Gpc‐1 is a determinant for mechanotransduction signaling. Taken together, these results suggest that Gpc‐1 activation by pressure leads to endothelial hyper‐permeability due to ROS and NO‐dependent pathways and contributes to PE in an in situ model of acute HF.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Acute Inotropic Effect of the Uremic Metabolite, Trimethylamine‐N‐Oxide (TMAO), on Human Cardiac Muscle
Authors: Oakley Carlee I. , Sanborn David , Rafie Nikita , Hendrix Matt , Stubbs Jason R. , Shawgo Tilitha , Daon Emmanuel , Zorn George , Wacker Michael J.
Published: June 2021

Background

Cardiovascular disease is endemic among patients with chronic kidney disease (CKD). Growing evidence suggests the gut microbiome plays an obligatory role in cardiovascular pathogenesis. TMAO is a downstream byproduct of intestinal microbe metabolism of phosphatidylcholine and L‐carnitine that may directly promote atherosclerosis formation. Since clearance of this uremic metabolite is dependent on urinary excretion, plasma levels of TMAO increase with decrements in kidney function. Association studies have linked plasma levels of TMAO to adverse cardiovascular outcomes in patients with renal dysfunction; however, to our knowledge, we are the first to investigate whether TMAO alone has any direct effect on cardiac contractility. In prior studies, we found TMAO to acutely increase contractile force in mouse hearts ex vivo. The objective of the current investigation was to determine if our findings translated to human heart tissue.

Methods

Human right atrial appendage biopsy tissue was retrieved during cardiopulmonary bypass procedures, prior to cannula placement. The cardiac muscle samples were attached to a force transducer and bubbled with oxygen inside an organ bath. Changes in contractility were measured after treatment with TMAO or vehicle (Ringer's solution).

Results

In our previous studies using mouse hearts, we found acute treatment with TMAO in the organ bath increased average contraction amplitude 20% and 41% at 300 μM and 3000 μM, respectively (P < 0.05, n = 6–7 animals). Langendorff reverse perfusion of hearts with 300 μM TMAO generated an even greater response than incubation and increased isometric force 32% (P < 0.05, n = 2–3). Consistent with what we observed in the animal model, incubation of human atrial muscle tissue with TMAO at 3,000 μM increased isometric tension 31% compared to vehicle (P < 0.05, n = 4–5).

Conclusions

TMAO, at pathological concentrations, directly increases cardiac contractility in both animal and human hearts. Initially, this inotropic effect may be beneficial or adaptive during CKD; however, chronic increases in cardiac contractility can promote cardiac remodeling and left ventricular hypertrophy. Further in vivo studies are needed to determine how chronic exposure to TMAO may contribute to cardiac pathology in CKD and to examine if TMAO represents a therapeutic target for reducing cardiovascular mortality in CKD patients.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Role Of P62 On Chronic Oxidative Stress‐Induced Myocytes Ca handling
Authors: Koh Yeojung , Jung Yooyeon , Lee Kwangjun , Salazar Gloria , Hwang Hyun Seok
Published: June 2021

Introduction

Recent studies have shown that the activity of autophagy impairs, and the accumulation of p62 protein, autophagy substrate, in the heart observes in heart failure patients and mouse models of cardiomyopathy. Accumulations of p62 protein are known to activate the intrinsic cellular stress. Abnormal Ca release is partly responsible for oxidative stress‐induced contractile dysfunction of myocytes in ischemic heart disease. Myocytes Ca release is controlled by a function of sarcoplasmic reticulum (SR) Ca store. However, the role of p62 protein on myocytes Ca regulation in the ischemic heart is not clear.

Purpose

To investigate the role of p62 on SR Ca regulation in myocytes isolated from mice with the Isoproterenol‐induced myocardial injury.

Methods

To test our hypothesis, both wild‐type (WT) and p62 knockout (KO) mice were used at 10–12 weeks of age. Myocytes isolated from WT and p62 KO mice (n=3 per group) injected with 200 mg/kg Isoproterenol (ISO; beta agonist, twice per day) for 0 (Base), 5 days, and 10 days. SR Ca handling and contractility measured in field‐stimulated single myocytes loaded with fluorescent Ca indicators (Fura‐2AM; cytosolic Ca loading). Amplitudes of caffeine (10 mM, 5 sec)‐induced Ca transients used as estimates of SR Ca store. Sets of heart from WT and p62 mice were processed for western blot (n=3 per group).

Results

The p62‐deficient myocytes had no difference of myocytes contractility, and SR Ca handling at the baseline compared to WT myocytes (n=35–45 cells per group). After acute ISO exposure (1μM for 1 min), WT myocytes increased systolic Ca release whereas p62‐deficient myocytes did not. An exposure of a submaximal oxidative stress (1μM; H2O2) in p62‐deficient myocytes, however, increased myocytes contractility and the fraction of Ca released from the SR during each beat (fractional Ca release; systolic Ca release over SR Ca store) after acute ISO stimulation (p<0.05). In WT mice injected with ISO for 5 days and 10 days, myocytes had a biphasic effect on myocytes contractility and fractional Ca release (n=15–45 cells per group, p<0.05). Interestingly, in p62‐deficient myocytes further increased myocytes contractility and fractional Ca release (Figure) on chronic ISO injections from 5 days to 10 days. WT mice hearts with chronic exposure to ISO for 10 days increased p62 protein expressions and suppressed the conversion of LC3 I to LC3 II.

Conclusion

Taken together, our results suggest that accumulations of p62 protein may directly cause SR Ca defects via beta‐adrenergic signaling in myocytes under chronic myocardial injury.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Antiarrhythmic Activity of NMDA Receptor Antagonists in Humans Versus Animal Models
Authors: Elnakish Mohammad T. , Repas Steven J. , Whitson Bryan A. , Mohler Peter J. , Janssen Paul M.L.
Published: June 2021

Understanding of cardiac ion channels as well as inventive ways to intend compound screening will allow a novel expectation for imminent discovery of antiarrhythmic remedies. In this regard, N‐methyl D‐aspartate receptor (NMDAR) antagonists, such as memantine, which are clinically approved for the treatment of Alzheimer's disease (AD), Huntington's disease, and dementia have displayed promising protective effects against cardiac arrhythmia in several animal models. However, our current data revealed that maximal ex‐vivo β‐adrenergic stimulation of the right ventricular (RV) papillary muscles, but not in‐vivo ECG analysis of thyroxine‐treated mice, exhibited arrhythmia in undoubtedly higher number (~ 62 %) compared to the control, and this even reached a greater level (~ 73 %) following memantine treatment. Transformation of outcomes acquired in animal models to human pathophysiology is frequently hampered by species‐dependent dissimilarities. Thus, it is critical to keep investigating the ex‐vivo effects of prospective attractive drugs on initiated arrhythmia and contractility in the ventricular human myocardium to confirm data that was exclusively acquired from animal models. Interestingly, our preliminary data illustrate that arrhythmia elicited by 100 nmol/L isoproterenol and 0.5 mmol/L caffeine in isolated RV muscles of non‐failing human hearts is inhibited by memantine in a concentration‐dependent manner with a full reserve at 50 μM. However, the exact IC50, mechanism, possibility of pro‐arrhythmia at a higher concentration as well as its impact on the contractile profile of cardiac muscle, which represents an important complementary safety measure to therapeutic efficacy is currently unknown. We have previously reported that zacopride; a moderate IK1 channel activator shows promising antiarrhythmic effects against generated arrhythmia in human ventricular myocardium using the same protocol. This opens the door for further investigation of the possible correlation between NMDAR‐IK1 channel‐Ca2+ signaling pathways in ventricular tachycardia, which is the leading cause of sudden arrhythmic death in the U.S.

Support or Funding Information

This study was supported by American Heart Association Great Rivers Affiliate Post‐doctoral Fellowship 16POST27760155 to M.T. Elnakish and National Heart, Lung, and Blood Institute Grant R01 HL‐113084 to P. M. L. Janssen.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.