Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Ventilatory responses to hypoxia in the toad Bufo paracnemis before and after a decrease in haemoglobin

T Wang1, L G Branco, M L Glass

  • 1Department of Physiology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Brazil.

The Journal of Experimental Biology
|January 1, 1994
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Serotonin in the dorsal periaqueductal gray inhibits panic-like defensive behaviors in rats exposed to acute hypoxia.

Neuroscience·2015
Same author

Central hydrogen sulphide mediates ventilatory responses to hypercapnia in adult conscious rats.

Acta physiologica (Oxford, England)·2014
Same author

Dependence on body size of respiratory function in Hoplias malabaricus (Teleostei, Erythrinidae) during graded hypoxia.

Fish physiology and biochemistry·2013
Same author

Endogenous preoptic hydrogen sulphide attenuates hypoxia-induced hyperventilation.

Acta physiologica (Oxford, England)·2013
Same author

Interaction between the carbon monoxide and nitric oxide pathways in the locus coeruleus during fever.

Neuroscience·2012
Same author

The enigma of aestivation in the African lungfish Protopterus dolloi--commentary on the paper by Perry et al.

Respiratory physiology & neurobiology·2007
Same journal

Interaction between dynamic reinforcement learning and working memory of pigeon: A comparative modeling study.

The Journal of experimental biology·2026
Same journal

Differential responses to photoperiod in juveniles of two migratory songbird species.

The Journal of experimental biology·2026
Same journal

A Drosophila overgrowth model reveals extracellular matrix crosslinking limits cardiovascular scaling.

The Journal of experimental biology·2026
Same journal

Control of High-speed Jumps: Removing rotation from the jumps of locusts (Schistocerca gregaria).

The Journal of experimental biology·2026
Same journal

Limits and mechanisms of honey bee colonial thermoregulation in the heat.

The Journal of experimental biology·2026
Same journal

Correction: Sprinting performance is linked to surface activity in scorpions.

The Journal of experimental biology·2026
See all related articles

Reduced blood oxygen-carrying capacity in toads did not alter breathing, suggesting oxygen partial pressure regulates ventilation. However, it did increase heart rate in normal conditions and reversed the typical response to low oxygen.

Area of Science:

  • Physiology
  • Comparative Physiology
  • Cardiovascular Physiology

Background:

  • The oxygen-carrying capacity of blood is crucial for cellular respiration.
  • Understanding how animals adapt to reduced oxygen levels is vital in physiology.
  • The toad Bufo paracnemis serves as a model organism for studying respiratory and cardiovascular adaptations.

Purpose of the Study:

  • To investigate the ventilatory and cardiovascular responses to decreased oxygen-carrying capacity in Bufo paracnemis.
  • To determine if oxygen partial pressure or oxygen content is the primary regulated variable in toad respiration.
  • To examine the effects of reduced oxygen transport on heart rate and blood pressure.

Main Methods:

  • Pulmonary ventilation was measured using a pneumotachographic technique.

Related Experiment Videos

  • Chronic arterial catheters were implanted for continuous monitoring of cardiac frequency and blood pressure.
  • Blood samples were analyzed for pH and partial pressure of oxygen (PO2) using established methods.
  • Hemoglobin concentrations were determined via the cyanmethemoglobin method.

    • Main Results:

    • The ventilatory response to hypoxia remained unaffected by the experimentally reduced blood oxygen-carrying capacity.
    • This suggests that the partial pressure of oxygen (PO2), not the total oxygen content, is the regulated variable for ventilation.
    • A reduction in oxygen-carrying capacity led to an increased heart rate under normoxic conditions.
    • Furthermore, a reversal of the typically observed hypoxic tachycardia was noted.

    Conclusions:

    • Oxygen partial pressure, rather than oxygen content, appears to be the key regulated variable for ventilation in Bufo paracnemis.
    • Reduced blood oxygen-carrying capacity significantly impacts cardiovascular function, altering heart rate responses to both normoxic and hypoxic conditions.
    • These findings contribute to our understanding of respiratory and cardiovascular regulation in amphibians facing altered oxygen transport.