Observations on Body Temperature and Activity in the Toad Bufo woodhousei fowleri

Copeia ◽  
1966 ◽  
Vol 1966 (3) ◽  
pp. 581 ◽  
Author(s):  
Sydney Hadfield
Keyword(s):  
Body Temperature ◽  
Bufo Woodhousei ◽  
Toad Bufo

Antipyretic effect of arginine vasotocin in toads

2000 ◽  
Vol 278 (6) ◽  
pp. R1408-R1414 ◽  
Author(s):  
K. C. Bicego-Nahas ◽  
A. A. Steiner ◽  
E. C. Carnio ◽  
J. Antunes-Rodrigues ◽  
L. G. S. Branco
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Temperature ◽  
Thermal Gradient ◽  
Arginine Vasotocin ◽  
Antipyretic Effect ◽  
The Central Nervous System ◽  
Preferred Body Temperature ◽  
Toad Bufo

Arginine vasotocin (AVT) is a nonmammalian analog of the mammalian hormone arginine vasopressin (AVP). These peptides are known for their antidiuretic and pressor effects. More recently, AVP has been recognized as an important antipyretic molecule in mammals. However, no information exists about the role of AVT in febrile ectotherms. We tested the hypothesis that AVT is an antipyretic molecule in the toad Bufo paracnemis. Toads equipped with a temperature probe were placed in a thermal gradient, and preferred body temperature was recorded continuously. A behavioral fever was observed after lipopolysaccharide (LPS) was injected systemically (200 μg/kg). Systemically injected AVT (300 pmol/kg) alone caused no significant change in body temperature, but abolished LPS-induced fever. Moreover, a smaller dose of AVT (10 pmol/kg), which did not affect LPS-induced fever when injected peripherally, abolished fever when injected intracerebroventricularly. We therefore conclude that AVT plays an antipyretic role in the central nervous system, by means of behavior, in an ectotherm, a fact consistent with the notion that AVT/AVP elicits antipyresis by reducing the thermoregulatory set point.

Observations on the Body Temperature and Activity in the Red Spotted Toad, Bufo punctatus

Copeia ◽  
1980 ◽  
Vol 1980 (2) ◽  
pp. 362 ◽  
Author(s):  
Robert G. Moore ◽  
Beatrice Auza Moore
Keyword(s):  
Body Temperature ◽  
The Body ◽  
Toad Bufo

Effects of temperature on contractile properties of skinned muscle fibers from three toad species

1987 ◽  
Vol 252 (2) ◽  
pp. R371-R375 ◽  
Author(s):  
I. A. Johnston ◽  
T. T. Gleeson
Keyword(s):  
Cold Tolerance ◽  
Thermal Sensitivity ◽  
Force Production ◽  
Rocky Mountain ◽  
Isometric Tension ◽  
Tropical Species ◽  
Tension Development ◽  
Tension Increase ◽  
Bufo Woodhousei ◽  
Toad Bufo

Single fast fibers were isolated from the iliofibularis muscles of three species of toad with different thermal minima for active locomotion: 8 degrees C, American toad, Bufo americanus; 15 degrees C, Rocky Mountain toad, Bufo woodhousei woodhousei; 22 degrees C, Cane toad, Bufo marinus. All experiments were carried out during the summer. Fibers were chemically skinned and maximum isometric tension and unloaded contraction velocity were determined at a series of temperatures between 0 and 35 degrees C. At 25-30 degrees C, isometric tension development has a low temperature dependence (R10 = 1.1-1.3) and is in the range of 210-260 kN X m-2 for each of the three toads. However, at 0-10 degrees C, absolute values of tension increase in the series (B. americanus greater than B. woodhousei greater than B. marinus; i.e., with increasing cold tolerance), while thermal sensitivity between 0 and 10 degrees C is inversely related to cold tolerance. For example, at 0 degree C, maximum isometric tension (Po) for the most northerly distributed species is three times higher than for the subtropical to tropical species (P less than 0.001). R10 for Po (0-10 degrees C) is 1.7 for B. marinus, 1.3 for B. w. woodhousei, and 1.0 for B. americanus. In contrast, unloaded shortening speeds were similar at any given temperature for the three species. It is concluded that adaptations in Bufo myosin for activity at low temperatures largely involves changes in force production.

Lymphatic regulation of hematocrit during hypoxia in the toad Bufo woodhousei

1995 ◽  
Vol 269 (4) ◽  
pp. R814-R821 ◽  
Author(s):  
G. M. Malvin ◽  
S. Macias ◽  
M. Sanchez ◽  
R. Dasalla ◽  
A. Park ◽  
...  
Keyword(s):  
Plasma Volume ◽  
Lymph Flow ◽  
Cholinergic Nerves ◽  
Arterial Blood ◽  
Rate Of Increase ◽  
Lymph Heart ◽  
Flow Through ◽  
Bufo Woodhousei ◽  
Induced Changes ◽  
Toad Bufo

Hypoxia rapidly increases hematocrit (Hct) in anuran amphibians by reducing plasma volume, but the mechanism(s) mediating this response is unknown. We tested the hypothesis that, during hypoxia, plasma volume is reduced by impaired lymph heart (LH) function, decreasing lymph flow into the circulation. In Bufo woodhousei, we measured the effects of hypoxia on Hct, lymph heart rate (LHR), LH pressure, the movement of dye from the dorsal lymph sac to the arterial blood, and flow through an open LH cannula. We also tested whether splenic contraction or cholinergic nerves contribute to the hypoxia-induced changes. Graded hypoxia between 21 and 4% O2 produced graded increases in Hct (P < 0.0001) and decreases in LHR (P = 0.01). Hypoxia reduced the rate of increase in arterial Evans blue concentration after injection into the dorsal lymph sac (P = 0.041) and decreased flow through an open LH cannula (P < 0.012). Hypoxia increased Hct and reduced LHR similarly in control, splenectomized, and sham-splenectomized toads. Atropine had no significant effect on Hct and LHR. These results indicate that the LHs play a regulatory role in hypoxia-induced hemoconcentration.

Postmetamorphic growth rates in a natural population of Fowler's toad, Bufo woodhousei fowleri

1974 ◽  
Vol 52 (12) ◽  
pp. 1489-1498 ◽  
Author(s):  
Raymond D. Clarke
Keyword(s):  
Growth Rates ◽  
The Body ◽  
Individual Growth ◽  
Length Increase ◽  
Sexual Characteristics ◽  
Size Growth ◽  
Body Sizes ◽  
Bufo Woodhousei ◽  
Fowler's Toad ◽  
Toad Bufo

A population of Fowler's toad (Bufo woodhousei fowleri) living on a golf course in New Haven, Connecticut, was studied for 3 years by the capture–mark–recapture method. Individual growth rates were determined using tibia length, which is isometric with body length, as the measure of size. Growth was rapid, with an average 6.58-fold length increase during the 1st year after metamorphosis. Males began to show secondary sexual characteristics about 1 year after metamorphosis; at this age the cohort began to overlap in body size with the older males. Females grew faster than males, but also reached a larger size, and the body sizes of the maturing female cohort began to overlap with the older females 1 month later than the males. The growth curve for length was inflected, which is predicted by von Bertalanffy's growth model.

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