La radiothyroïdectomie et son effet sur la consommation d'oxygène chez les cichlidés Aequidens latifrons

1971 ◽  
Vol 49 (3) ◽  
pp. 423-425 ◽  
Author(s):  
M.-L. Ruhland

The thyroidectomy produced after radioiodide immersion of the cichlid fish Aequidens latifrons during 5 months was characterized by progressive alterations of the thyroid tissue from the disappearance of colloid, the degeneration of thyroid cells until an intensive proliferation of fibrous tissue, which replaced the thyroid follicles of the gland. Autoradiographic examinations revealed a few microfollicles, which presented a small activity.The consequential effects on the respiratory exchanges are significant decreases of the oxygen consumption which are progressive and more important than the decreases obtained after thiourea treatment. The decreases reach a third of the normal rate of oxygen consumption, 32% after a long treatment period (150 days). This proves the relationship between the thyroid gland and the oxygen consumption of fishes.

Author(s):  
R. C. Newell ◽  
H. R. Northcroft

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.


2001 ◽  
Vol 204 (12) ◽  
pp. 2133-2144 ◽  
Author(s):  
G. Froget ◽  
P. J. Butler ◽  
Y. Handrich ◽  
A. J. Woakes

SUMMARY The use of heart rate to estimate field metabolic rate has become a more widely used technique. However, this method also has some limitations, among which is the possible impact that several variables such as sex, body condition (i.e. body fat stores) and/or inactivity might have on the relationship between heart rate and rate of oxygen consumption. In the present study, we investigate the extent to which body condition can affect the use of heart rate as an indicator of the rate of oxygen consumption. Twenty-two breeding king penguins (Aptenodytes patagonicus) were exercised on a variable-speed treadmill. These birds were allocated to four groups according to their sex and whether or not they had been fasting. Linear regression equations were used to describe the relationship between heart rate and the rate of oxygen consumption for each group. There were significant differences between the regression equations for the four groups. Good relationships were obtained between resting and active oxygen pulses and an index of the body condition of the birds. Validation experiments on six courting king penguins showed that the use of a combination of resting oxygen pulse and active oxygen pulse gave the best estimate of the rate of oxygen consumption V̇O2. The mean percentage error between predicted and measured V̇O2 was only +0.81% for the six birds. We conclude that heart rate can be used to estimate rate of oxygen consumption in free-ranging king penguins even over a small time scale (30min). However, (i) the type of activity of the bird must be known and (ii) the body condition of the bird must be accurately determined. More investigations on the impact of fasting and/or inactivity on this relationship are required to refine these estimates further.


1973 ◽  
Vol 59 (1) ◽  
pp. 255-266
Author(s):  
H. J. ATKINSON

1. The rate of oxygen consumption of individual males of Enoplus brevis and E. communis was measured at 15 °C and at each of four oxygen tensions, 135, 75, 35, and 12 Torr, after at least 12 h experience of these conditions. 2. It was clearly demonstrated that the level of oxygen consumption of both species was reduced by each lowering of the imposed oxygen tension. 3. In all cases the oxygen consumption of each species fell with increasing body size. On a unit dry-weight basis the oxygen consumption of E. brevis is greater than that of the larger E. communis, but after allowing for the difference of body size the two species have more or less similar oxygen uptakes at all oxygen tensions. 4. In E. brevis oxygen tension influenced the relationship of body size and metabolism, the slope relating oxygen consumption and body weight becomes steeper with decreasing oxygen tension. This effect was not shown by E. communis. 5. Some general factors influencing the availability of oxygen to nematodes are considered.


2002 ◽  
Vol 205 (16) ◽  
pp. 2511-2517 ◽  
Author(s):  
G. Froget ◽  
Y. Handrich ◽  
Y. Le Maho ◽  
J.-L. Rouanet ◽  
A. J. Woakes ◽  
...  

SUMMARY This study investigated whether exposure to low ambient temperature could be used as an alternative to exercise for calibrating heart rate (fH)against rate of oxygen consumption(V̇O2) for subsequent use of fH to estimate V̇O2 in free-ranging animals. Using the relationship between the oxygen pulse (OP, the amount of oxygen used per heart beat) and an index of body condition (or nutritional index, NI), a relationship between fH and V̇O2 was established for resting king penguins exposed to a variety of environmental temperatures. Although there was a small but significant increase in the OP above and below the lower critical temperature (-4.9°C), there was no difference in the relationship obtained between the OP and body condition (NI)obtained above or below the lower critical temperature. These results were then compared with those obtained in a previous study in which the relationship between fH and V̇O2 had been established for king penguins during steady-state exercise. The relationship between OP and NI in the present study was not significantly different from the relationship between resting OP and NI in the previous study. However, the relationship was different from that between active OP and NI. We conclude that, at least for king penguins, although thermoregulation does not affect the relationship between resting OP and NI, temperature cannot be used as an alternative to exercise for calibrating fH against V̇O2 for subsequent use of fH to estimate V̇O2 in free-ranging animals.


1972 ◽  
Vol 59 (1) ◽  
pp. 60-76 ◽  
Author(s):  
F. L. Vieira ◽  
S. R. Caplan ◽  
A. Essig

Sodium transport and oxygen consumption were studied simultaneously in the short-circuited frog skin. Sodium transport was evaluated from Io/F, where Io is the short-circuit current measured with standard Ringer's solution bathing each surface and F is the Faraday constant. Oxygen tension was measured polarographically. Under a variety of circumstances the rate of oxygen consumption from the outer solution exceeded that from the inner solution, the ratio being constant (0.57 ± 0.09 SD). Both Io and the associated rate of oxygen consumption Jro declined nonlinearly with time, but the relationship between them was linear, suggesting that the basal oxygen consumption was constant. For each skin numerous experimental points were fitted by the best straight line. The intercept (Jro)Io=0 then gave the basal oxygen consumption, and the slope dNa/dO2 gave an apparent stoichiometric ratio for a given skin. The basal oxygen consumption was about one-half the total oxygen consumption in a representative untreated short-circuited skin. Values of dNa/dO2 in 10 skins varied significantly, ranging from 7.1 to 30.9 (as compared with Zerahn's and Leaf and Renshaw's values of about 18). KCN abolished both Io and Jro. 2,4-dinitrophenol (DNP) depressed Io while increasing Jro four- to fivefold. Anti-diuretic hormone stimulated and ouabain depressed both Io and Jro; in both cases apparent stoichiometric ratios were preserved.


1981 ◽  
Vol 98 (1) ◽  
pp. 43-49 ◽  
Author(s):  
T.J. Wilkin ◽  
A. Gunn ◽  
M. Al Moussa ◽  
T. E. Isles ◽  
J. Crooks ◽  
...  

Abstract. Quantitative histometric methods were used to established the relationship between the extent of thyroid lymphocytic infiltration at operation, and outcome exactly 18 months later in 50 surgically-treated Graves' disease patients prepared by carbimazole and triiodothyronine. Periods of pre-operative treatment, surgical technique, histometric analysis and diagnostic criteria were all standardised. Controls (107) were obtained from the forensic laboratory. Thirty-seven patients became euthyroid, but there was no relationship between outcome and epithelial or lymphoid content of the thyroid gland. Neither was there any correlation between the size of lymphoid infiltrate and epithelial mass of the resected thyroids, suggesting that simple lymphocyte infiltrations do not replace thyroid tissue as once thought. The variation in thyroid epithelial content was nearly 3-fold, so that a surgeon, even if able accurately to judge the anatomical mass of the remnant, would still have little or no idea of its functional mass. The scatter of epithelial content was even greater in glands from patients prepared for surgery by propranolol alone (38 glands, variation × 5.5) or propranolol and iodide (32 glands, variation × 5.9). Outcome after sub-total thyroidectomy for Graves' disease seems unrelated to the lymphocyte content of the gland and it is questionable to what extent the surgeon can either predict or control the outcome of thyroidectomy in individual Graves' disease patients.


2021 ◽  
Vol 26 (2(49)) ◽  
pp. 89-97
Author(s):  
R. V. Yanko

Introduction: Despite the well-studied effect of alimentary deprivation on the body, the literature data on its effect on functional activity and, in particular, on morphological changes in the thyroid gland are single and often contradictory, which does not allow unambiguous conclusions. All this requires a more detailed study of the role and mechanisms of the impact of restricted nutrition on the thyroid gland. Aim: To investigate the effect of alimentary deprivation on morphological changes in the thyroid gland of young rats. Methods: The study was conducted on 24 male Wistar rats aged 3 months. Rats of all groups were in uniform conditions, on a standard diet. Animals of the experimental group, for 28 days, received a diet reduced by 30 %. Work with rats was carried out in accordance with the principles of the Declaration of Helsinki. Histological preparations were made from the central areas of the thyroid tissue according to the standard method. Using a digital camera, the micropreparations were photographed under a Nikon Eclipse E 100 microscope (Japan). Morphometry was performed using a computer program "Image J". Results: Histological analysis of the rat's thyroid gland affected by alimentary deprivation revealed that it had an unchanged physiological structure. The follicles were mostly of oval shape and of various sizes. Colloid in the follicles of experimental animals is of moderate density and contains numerous resorption vacuoles. Thyroid cells are of prismatic and cubic shape. It was found that in the thyroid gland of experimental rats the area of ​​follicles, colloid, their inner diameter decreases, the height of thyrocytes increases, the stereological resorption index increases and the colloid accumulation index decreases, the number of interfollicular islands increases. Also in experimental animals there was a decrease in the width of the interlobar and interfollicular connective tissue. Conclusion: In rats fed on a reduced diet, morphological signs of increased functional activity of the thyroid gland were found.


1998 ◽  
Vol 201 (19) ◽  
pp. 2779-2789 ◽  
Author(s):  
DM Webber ◽  
RG Boutilier ◽  
SR Kerr

Adult Atlantic cod (2 kg Gadus morhua) were fitted with Doppler ultrasonic flow-probes to measure ventral aortic outflow (i.e. cardiac output). The probes remained patent for upwards of 3 months, during which time detailed relationships between cardiac output (), heart rate (fh) and rate of oxygen consumption (O2) were determined as a function of swimming speed and temperature (5 degreesC and 10 degreesC). The rate of oxygen consumption increased linearly with and exponentially with swimming speed. A very good correlation was observed between O2 and (r2=0.86) compared with the correlation between O2 and fh (r2=0.50 for all 10 degreesC data and r2=0.86 for all 5 degreesC data). However, the O2 versus fh correlation gradually improved over approximately 1 week after surgery (r2=0.86). The relationship between O2 and was independent of temperature, while the relationship between O2 and fh changed with temperature. Hence, calculating O2 from is simpler and does not require that temperature be recorded simultaneously. Variations in cardiac output were determined more by changes in stroke volume (Vs) than by fh; therefore, fh was a less reliable predictor of metabolic rate than was . Given that can be used to estimate O2 so faithfully, the advent of a cardiac output telemeter would enable robust estimates to be made of the activity metabolism of free-ranging fish in nature, thereby strengthening one of the weakest links in the bioenergetic models of fisheries biology.


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