Central respiratory activity of the tadpole in vitro brain stem is modulated diversely by nitric oxide

2002 ◽  
Vol 283 (2) ◽  
pp. R417-R428 ◽  
Author(s):  
Michael B. Harris ◽  
Richard J. A. Wilson ◽  
Konstantinon Vasilakos ◽  
Barbara E. Taylor ◽  
John E. Remmers
Keyword(s):  
Nitric Oxide ◽  
Rana Catesbeiana ◽  
Lung Ventilation ◽  
Central Chemosensitivity ◽  
Respiratory Rhythmogenesis ◽  
Specific Frequency ◽  
Central Respiratory Activity ◽  
Ph Conditions ◽  
Respiratory Rhythms

Nitric oxide (NO) is a potent central neuromodulator of respiration, yet its scope and site of action are unclear. We used 7-nitroindazole (7-NI), a selective inhibitor of endogenous neuronal NO synthesis, to investigate the neurogenesis of respiration in larval bullfrog ( Rana catesbeiana) isolated brain stems. 7-NI treatment (0.0625–0.75 mM) increased the specific frequency of buccal ventilation (BV) events, indicating influence on BV central rhythm generators (CRGs). The drug reduced occurrence, altered burst shape, and disrupted clustering of lung ventilation (LV) events, without altering their specific frequency. LV burst occurrence and clustering also differed between pH conditions. We conclude that NO has diverse effects on respiratory rhythmogenesis, being necessary for the expression of respiratory rhythms, inhibiting the frequency of BV CRG, and affecting both shape and clustering of LV bursts through conditional modulation of LV CRG. We confirm central chemosensitivity in these preparations and demonstrate chemomodulation of LV burst clustering and occurrence but not specific frequency. Results support distinct oscillators underlying LV and BV CRGs.

Sites of respiratory rhythmogenesis during development in the tadpole

2001 ◽  
Vol 280 (4) ◽  
pp. R913-R920 ◽  
Author(s):  
C. S. Torgerson ◽  
M. J. Gdovin ◽  
J. E. Remmers
Keyword(s):  
Brain Stem ◽  
Rana Catesbeiana ◽  
Lung Ventilation ◽  
Respiratory Rhythmogenesis ◽  
Amphibian Larvae ◽  
Before And After ◽  
Lung Ventilator ◽  
Necessary And Sufficient ◽  
Stem Segments

During ontogeny, amphibian larvae experience a dramatic alteration in the motor act of breathing as the premetamorphic gill breather develops into the postmetamorphic lung ventilator. We tested the hypothesis that the site of lung rhythmogenesis relocates during metamorphosis by recording fictive lung ventilation before and after transecting the in vitro brain stem of pre- and postmetamorphic Rana catesbeiana into four segments. In premetamorphic tadpoles, the two caudalmost brain stem segments combined proved to be the minimum brain stem configuration necessary and sufficient for lung burst generation. In the postmetamorphic counterpart, this function was supplied by the combination of the two rostralmost brain stem segments. In the postmetamorphic brain stem, a 500-μm segment lying just rostral to cranial nerve IX conveys rhythmogenic capability to neighboring rostral or caudal segments. We conclude that lung rhythmogenic capability translocates rostrally during development as the tadpole shifts from gill to lung ventilation.

Cyclic AMP induces a relaxation response in the bullfrog Rana catesbeiana, but nitric oxide does not.

1997 ◽  
Vol 200 (20) ◽  
pp. 2669-2674
Author(s):  
L W Kline ◽  
M L Zhang ◽  
P K Pang
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cyclic Amp ◽  
Rana Catesbeiana ◽  
Nerve Fibers ◽  
In Vitro Studies ◽  
Gallbladder Motility ◽  
Cyclic Monophosphate ◽  
Oxide Synthase

Cholecystokinin octapeptide (CCK), acetylcholine (ACh) and ceruletide have been shown to produce contraction in bullfrog (Rana catesbeiana) gallbladder strips. Agents capable of relaxing the bullfrog gallbladder are less numerous. Calcitonin gene-related peptide reduced the amount of both CCK- and ACh-induced tension in bullfrog gallbladder strips. The purpose of this study was to determine whether vasoactive intestinal peptide (VIP), nitric oxide (NO) and the second messengers cyclic GMP or cyclic AMP had any effect on gallbladder motility in the bullfrog. In vitro tension studies using l-NG-nitro-arginine methyl ester, Methylene Blue, sodium nitroprusside and N2,2'-O-dibutyryl guanosine 3',5'-cyclic monophosphate suggested that nitric oxide did not modulate gallbladder motility in the bullfrog gallbladder. Histochemical staining for NADPH diaphorase (nitric oxide synthase) failed to demonstrate nerve fibers containing nitric oxide synthase in the bullfrog gallbladder. In vitro studies demonstrated that VIP had no effect on CCK-induced tension. However, in vitro studies using either 8-bromoadenosine 3',5'-cyclic monophosphate or forskolin demonstrated that both agents relaxed strips precontracted with CCK. The results of this study suggested that, while neither NO nor VIP had a role in modulating bullfrog gallbladder motility, cyclic AMP was capable of modulating bullfrog gallbladder motility.

Ontogeny of central chemoreception during fictive gill and lung ventilation in an in vitro brainstem preparation of Rana catesbeiana

1997 ◽  
Vol 200 (15) ◽  
pp. 2063-2072 ◽  
Author(s):  
C Torgerson ◽  
M Gdovin ◽  
J Remmers
Keyword(s):  
Rana Catesbeiana ◽  
Cranial Nerves ◽  
Lung Ventilation ◽  
Artificial Cerebrospinal Fluid ◽  
Gill Ventilation ◽  
Central Chemoreception ◽  
Bullfrog Tadpole ◽  
Spontaneously Breathing ◽  
Hypercapnic Response

An isolated brainstem preparation of the bullfrog tadpole, Rana catesbeiana, displays coordinated rhythmic bursting activities in cranial nerves V, VII and X in vitro. In decerebrate, spontaneously breathing tadpoles, we have previously shown that these bursts correspond to fluctuations in buccal and lung pressures and to bursts of activity in the buccal levator muscle H3a. This demonstrates that the rhythmic bursting activities recorded in vitro represent fictive gill and lung ventilation. To investigate the ontogeny of central respiratory chemoreception during the transition from gill to lung ventilation, we superfused the isolated brainstems of four larval stage groups with oxygenated artificial cerebrospinal fluid at various levels of PCO2. We measured shifts in the pattern of fictive respiratory output and the response to central hypercapnic stimulation throughout development. At normal PCO2 (2.3 kPa), stage 3­9 tadpoles displayed rhythmic neural bursts associated with gill ventilation, while stages 10­14 and 15­19 tadpoles produced oscillating bursting activity associated with both gill and lung respiration, and tadpoles at stages 20­25 displayed neural activity predominantly associated with lung ventilation. In stage 3­9 tadpoles, variations in PCO2 of the superfusate (0.5­6.0 kPa) caused almost no change in fictive gill or lung ventilation. By contrast, stage 10­14 tadpoles showed a significant hypercapnic response (P<0.05) in the amplitude and frequency of fictive gill ventilation, which was accompanied by a significant increase (P<0.05) in the burst amplitude and respiratory output of cranial nerve X over that occurring at all other stages. The amplitude and frequency of fictive gill ventilation in stages 15­19 increased significantly (P<0.05) in response to pH reduction, but became insensitive to hypercapnia at stages 20­25. The frequency of fictive lung ventilation was unresponsive to hypercapnia in stage 10­14, increased significantly by stage 15­19 (P<0.05) and became maximal (P<0.05) in stages 20­25. Overall, we describe the ontological development of central respiratory chemoreceptors driving respiratory output in the larval amphibian, demonstrating transfer in central chemoreceptive influence from gill to lung regulation during metamorphic stages. In addition, we provide novel evidence for the stimulatory influence of central chemoreceptors on fictive gill ventilation in response to CO2.

Fictive Gill and Lung Ventilation in the Pre- and Postmetamorphic Tadpole Brain Stem

1998 ◽  
Vol 80 (4) ◽  
pp. 2015-2022 ◽  
Author(s):  
C. S. Torgerson ◽  
M. J. Gdovin ◽  
J. E. Remmers
Keyword(s):  
Brain Stem ◽  
Rana Catesbeiana ◽  
Low Frequency ◽  
Lung Ventilation ◽  
High Amplitude ◽  
Spinal Nerve ◽  
Gill Ventilation ◽  
Respiratory Behavior ◽  
Spontaneously Breathing

Torgerson, C. S., M. J. Gdovin, and J. E. Remmers. Fictive gill and lung ventilation in the pre- and postmetamorphic tadpole brain stem. J. Neurophysiol. 80: 2015–2022, 1998. The pattern of efferent neural activity recorded from the isolated brain stem preparation of the tadpole Rana catesbeiana was examined to characterize fictive gill and lung ventilations during ontogeny. In vitro recordings from cranial nerve (CN) roots V, VII, and X and spinal nerve (SN) root II of premetamorphic tadpoles showed a coordinated sequence of rhythmic bursts occurring in one of two patterns, pattern1, high-frequency, low-amplitude bursts lacking corresponding activity in SN II and pattern 2, low-frequency, high-amplitude bursts with coincident bursts in SN II. These two patterns corresponded to gill and lung ventilatory burst patterns, respectively, recorded from nerve roots of decerebrate, spontaneously breathing tadpoles. Similar patterns were observed in brain stem preparations from postmetamorphic tadpoles except that they showed a greater frequency of lung bursts and they expressed fictive gill ventilation in SN II. The laryngeal branch of the vagus (Xl) displayed efferent bursts in phase with gill and lung activity, suggesting fictive glottal constriction during gill ventilation and glottal dilation during lung ventilation. The fictive gill ventilatory cycle of pre- and postmetamorphic tadpoles was characterized by a rostral to caudal sequence of CN bursts. The fictive lung ventilatory pattern in the premetamorphic animal was initiated by augmenting CN VII discharge followed by synchronous bursts in CN V, X, SN II, and Xl. By contrast, postmetamorphic patterns of fictive lung ventilation were characterized by lung burst activity in SN II that preceded burst onset in CN V and followed the lead burst in CN VII. We conclude that recruitment and timing of pattern 1 and pattern 2 rhythmic bursts recorded in vitro closely resemble that recorded during spontaneous respiratory behavior, indicating that the two patterns are the neural equivalent of gill and lung ventilation, respectively. Further, fictive gill and lung ventilatory patterns in postmetamorphic tadpoles differ in burst onset latency from premetamorphic tadpole patterns and resemble fictive oropharyngeal and pulmonary burst cycles in adult frogs.

Location of central respiratory chemoreceptors in the developing tadpole

2001 ◽  
Vol 280 (4) ◽  
pp. R921-R928 ◽  
Author(s):  
C. S. Torgerson ◽  
M. J. Gdovin ◽  
R. Brandt ◽  
J. E. Remmers
Keyword(s):  
Cerebrospinal Fluid ◽  
Brain Stem ◽  
Rana Catesbeiana ◽  
Lung Ventilation ◽  
Maximum Reduction ◽  
Amphibian Larvae ◽  
Artificial Cerebrospinal Fluid ◽  
Premetamorphic Tadpole

The location of central respiratory chemoreceptors in amphibian larvae may change as the central chemoreceptive function shifts from driving gill to driving lung ventilation during metamorphosis. We examined this possibility in the in vitro brain stem of the pre- and postmetamorphic Rana catesbeiana tadpole by microinjecting hypercapnic artificial cerebrospinal fluid (aCSF) while recording fictive lung ventilation. The rostral and caudal brain stem were separately explored systematically using injections of 11 nl of aCSF equilibrated with 100% CO2 that transiently acidified a 500-μm region, producing a maximum reduction in pH of 0.23 ± 0.06 at the site of injection. In postmetamorphic tadpoles, chemoreceptive sites were concentrated in the rostral compared with the caudal brain stem. No such segregation was observed in the premetamorphic tadpole. We conclude that, as in lung rhythmogenic function, respiratory chemosensitivity emerges rostrally in the amphibian brain stem during development.

502: Pressure Induces Nitric Oxide Production by Human Ureteral Cells in Vitro

2005 ◽  
Vol 173 (4S) ◽  
pp. 137-137
Author(s):  
Michael M. Ohebshalom ◽  
Stella K. Maeng ◽  
Jie Chen ◽  
Dix P. Poppas ◽  
Diane Felsen
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Production ◽  
Oxide Production

Effects of sodium nitroprusside(a donor of nitric oxide) on development of porcine preantral follicle cultured in vitro

2011 ◽  
Vol 37 (1) ◽  
pp. 55-59
Author(s):  
Qing QUAN ◽  
Yong TAO ◽  
Xiao-rong ZHANG ◽  
Gui-dong YAO ◽  
Jin-ju WANG
Keyword(s):  
Nitric Oxide ◽  
Sodium Nitroprusside ◽  
Preantral Follicle

Appraisal of Immunological Impacts of Melaleuca leucadendra Extract over Macrophage Performance in Vitro

2020 ◽  
Keyword(s):  
Nitric Oxide ◽  
Interleukin 2 ◽  
Dependent Manner ◽  
Reduced Pressure ◽  
Medical Plant ◽  
Dose Dependent ◽  
Level Production ◽  
Melaleuca Leucadendra ◽  
Phagocytic Killing

This trial research was performed to discuss the immune-influence of Melaleuca leucadendra ‘paper-bark tree’ dried leaves which is an important medical plant known in many regions in the world. The leaves were dissolved in a mixture of (ethanol + water) (3:1) mixture, then filtered, evaporated and dried under reduced pressure to obtain leaves extract. The macrophages of blood derived origin were provided from rats and mixed with three different leaves extracts doses in tissue culture plates and incubated then stained with fluorescent acridine orange and examined under fluorescent microscope to assess the phagocytic and killing potency. The wells contents were aspirated and assayed for nitric oxide and interleukin-2 levels. The results displayed an obvious increase in phagocytic, killing performance as well as nitric oxide and IL-2 level production than control in a dose dependent manner. The obtained results suggested the immune-stimulant impact of the paper-bark tree leaves.

Investigation of Oral Subacute Toxicity and In-Vitro Antioxidant Activity of Standardized Methanolic Extract of Quercus serrata Leaves

2020 ◽  
Vol 16 ◽  
Author(s):  
Maibam Beebina Chanu ◽  
Biseshwori Thongam ◽  
Khumukcham Nongalleima ◽  
Hans Raj Bhat ◽  
Surajit Kumar Ghosh ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Antioxidant Activity ◽  
Biochemical Parameters ◽  
Methanolic Extract ◽  
Reducing Power ◽  
Quercus Serrata ◽  
Control Group ◽  
Blood Cell Count ◽  
Toxicological Profile

Background: Quercus serrata Murray leaves have been used traditionally in the treatment of diabetes, dysmenorrhoea, inflammation and urinary tract infection. So, far no study had been reported on the toxicological profile and antioxidant properties of the plant. Objective: The present study was aimed to investigate the in-vivo toxicological profile and in-vitro antioxidant activities of the methanolic extract of standardized Quercus serrata leaves. Methods: Per-oral sub-acute toxicity study was performed in rats using three dose levels (200, 400 and 800 mg/kg b.w.) of the extract for 28-days. Control group received gum acacia suspended in water. Bodyweight was measured weekly. Biochemical parameters were analysed using the serum, the blood-cell count was done using whole blood. Pathological changes were also checked in highly perfused tissues. Further, in-vitro reducing power assay, nitric oxide scavenging assay, DPPH free-radical scavenging assay were performed to check the antioxidant activity of the extract. Results: There were no significant alterations in the blood-cell count and biochemical parameters analysed in the treatment group when compared with the normal control. Histopathology study of liver, kidney, pancreas, heart and brain revealed normal cellular architecture in the treatment groups alike the control group animals. Quercus serrata also showed a significant reduction of DPPH with IC50 4.48±0.254 µg/mL, in-vitro reducing power activity with IC50121.65±0.320 µg/mL and nitric oxide scavenging activity IC50 106.43±0.338 µg/mL. Conclusion: The above study showed that standardized methanolic extract of Quercus serrata leaves was safe after subacute oral administration in rats and has good antioxidant potential.

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