Ventilatory and metabolic responses to hypoxia in the smallest simian primate, the pygmy marmoset

2002 ◽  
Vol 92 (1) ◽  
pp. 202-210 ◽  
Author(s):  
Glenn J. Tattersall ◽  
James L. Blank ◽  
Stephen C. Wood

The pygmy marmoset ( Cebuella pygmaea) is the smallest New World Monkey (average body mass of 120–130 g). As such, it faces possible challenges to thermoregulation. Small mammals (e.g., rats) are well known to lower body temperature and metabolism in response to hypoxia; however, small primates have not been studied in this respect nor have, in general, the interactions between metabolism and ventilation. Because little is known about these responses in small primates, it seemed of great interest to assess the hypoxia-induced metabolic depression and drop in body temperature and the associated ventilatory requirements in this species under hypoxic conditions. Exposure to graded hypoxia (30 min at each of 18, 16, 14, 12, and 10% O2) caused body temperature to drop from the normoxic value of 39 to 37°C. This was accompanied by a marked metabolic depression (O2 consumption was ∼68% of the normoxic value, implying a suppression of metabolism greater than that predicted from a typical value of the effect of 10°C change on metabolism of 2–3 times). Minute ventilation declined in parallel to metabolism, maintaining a constant air-convection requirement during hypoxia; thus this species did not show the typical mammalian hyperventilation. Acute exposure to 10% O2 led to a similar overall decline in metabolism and body temperature and qualitative differences in the timing of these changes. The pygmy marmoset shares some similarities in its hypoxic metabolic response with other mammals of similar size yet appears to be unique in its much diminished ventilatory response to hypoxia.

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5600 ◽  
Author(s):  
Rebecca Naomi Cliffe ◽  
David Michael Scantlebury ◽  
Sarah Jane Kennedy ◽  
Judy Avey-Arroyo ◽  
Daniel Mindich ◽  
...  

Poikilotherms and homeotherms have different, well-defined metabolic responses to ambient temperature (Ta), but both groups have high power costs at high temperatures. Sloths (Bradypus) are critically limited by rates of energy acquisition and it has previously been suggested that their unusual departure from homeothermy mitigates the associated costs. No studies, however, have examined how sloth body temperature and metabolic rate vary with Ta. Here we measured the oxygen consumption (VO2) of eight brown-throated sloths (B. variegatus) at variable Ta’s and found that VO2 indeed varied in an unusual manner with what appeared to be a reversal of the standard homeotherm pattern. Sloth VO2 increased with Ta, peaking in a metabolic plateau (nominal ‘thermally-active zone’ (TAZ)) before decreasing again at higher Ta values. We suggest that this pattern enables sloths to minimise energy expenditure over a wide range of conditions, which is likely to be crucial for survival in an animal that operates under severe energetic constraints. To our knowledge, this is the first evidence of a mammal provisionally invoking metabolic depression in response to increasing Ta’s, without entering into a state of torpor, aestivation or hibernation.


Author(s):  
Taehee Jo ◽  
Dong Nyeok Jeon ◽  
Hyun Ho Han

Abstract Background The posterior thigh-based profunda artery perforator (PAP) flap has been an emerging option as a secondary choice in breast reconstructions. However, whether a PAP flap could consistently serve as the secondary option in slim patients has not been investigated. Methods Records of immediate unilateral breast reconstructions performed from May 2017 to June 2019 were reviewed. PAP flap breast reconstructions were compared with standard deep inferior epigastric perforator (DIEP) flap breast reconstructions, and were grouped into single or stacked PAP flaps for further analysis. Results Overall, 43 PAP flaps were performed to reconstruct 32 breasts. Eleven patients underwent stacked PAP flap reconstruction, while 17 patients underwent 21 single PAP flap reconstruction. The average body mass index (BMI) of the patients was 22.2 ± 0.5 kg/m2. The results were as follows: no total loss, one case of venous congestion (2.3%), two donor site wound dehiscence cases (4.7%), and one case of fat necrosis from partial flap loss (2.3%). When compared with 192 DIEP flap reconstructions, the final DIEP flap supplied 98.1 ± 1.7% of mastectomy weight, while the final PAP flap supplied 114.1 ± 6.2% of mastectomy weight (p < 0.005), demonstrating that PAP flaps can successfully supply final reconstruction volume. In a separate analysis, single PAP flaps successfully supplied 104.2% (84.2-144.4%) of mastectomy weights, while stacked PAP flaps supplied 103.7% (98.8-115.2%) of mastectomy weights. Conclusion In our series of PAP flap reconstructions performed in low-to-normal BMI patients, we found that PAP flaps, as single or stacked flaps, provide sufficient volume to reconstruct mastectomy defects.


1988 ◽  
Vol 64 (6) ◽  
pp. 2544-2551 ◽  
Author(s):  
H. Rigatto ◽  
C. Wiebe ◽  
C. Rigatto ◽  
D. S. Lee ◽  
D. Cates

We studied the ventilatory response to hypoxia in 11 unanesthetized newborn kittens (n = 54) between 2 and 36 days of age by use of a flow-through system. During quiet sleep, with a decrease in inspired O2 fraction from 21 to 10%, minute ventilation increased from 0.828 +/- 0.029 to 1.166 +/- 0.047 l.min-1.kg-1 (P less than 0.001) and then decreased to 0.929 +/- 0.043 by 10 min of hypoxia. The late decrease in ventilation during hypoxia was related to a decrease in tidal volume (P less than 0.001). Respiratory frequency increased from 47 +/- 1 to 56 +/- 2 breaths/min, and integrated diaphragmatic activity increased from 14.9 +/- 0.9 to 20.2 +/- 1.4 arbitrary units; both remained elevated during hypoxia (P less than 0.001). Younger kittens (less than 10 days) had a greater decrease in ventilation than older kittens. These results suggest that the late decrease in ventilation during hypoxia in the newborn kitten is not central but is due to a peripheral mechanism located in the lungs or respiratory pump and affecting tidal volume primarily. We speculate that either pulmonary bronchoconstriction or mechanical uncoupling of diaphragm and chest wall may be involved.


1987 ◽  
Vol 253 (2) ◽  
pp. R222-R227 ◽  
Author(s):  
J. N. Stinner

The cardiovascular adjustments associated with elevated metabolic demand caused by rising body temperature were investigated in Coluber constrictor. From 16 to 35 degrees C, O2 consumption increased roughly ninefold. Systemic blood flow, determined by the Fick method, increased approximately 4.5-fold and arteriovenous O2 difference increased approximately 2-fold. Heart rate steadily increased over the temperature range examined. At the cooler temperatures stroke volume also increased but, above approximately 25 degrees C, stroke volume declined with rising temperature. The changes in stroke volume may result from the direct effect of temperature on myocardial contractility. The thermal dependence of blood convection requirement in C. constrictor is similar to changes in air convection requirement determined in a previous study. Consequently the minute ventilation-to-perfusion ratio appears to be independent of temperature, at least from 20 to 35 degrees C. Systemic arterial blood pressure increases with rising body temperature due to the rise in cardiac output, whereas vascular resistance declines. Blood pressure in snakes disturbed by the investigator is roughly two times higher than in resting animals at all temperatures studied. This marked change in blood pressure suggests an "alarm reaction" mediated by the sympathetic nervous system.


1987 ◽  
Vol 62 (6) ◽  
pp. 2477-2484 ◽  
Author(s):  
H. Gautier ◽  
M. Bonora ◽  
S. A. Schultz ◽  
J. E. Remmers

Experiments were carried out on conscious cats to evaluate the general characteristics and modes of action of hypoxia on thermoregulation during cold stress. Intact and carotid-denervated (CD) conscious cats were exposed to ambient hypoxia (low inspired O2 fraction) or CO hypoxia in prevailing laboratory (23–25 degrees C) or cold (5–8 degrees C) environments. In the cold, both groups promptly decreased shivering and body temperature when exposed to either type of hypoxia. Small increases in CO2 concentration reinstituted shivering in both groups. At the same inspired concentration of O2, CD animals decreased shivering and body temperature more than intact cats. While this difference resulted, in part, from a lower alveolar PO2 in CD cats, a difference between intact and CD cats was apparent when the two groups were compared at the same alveolar PO2. During more prolonged hypoxia (45 min), shivering returned but did not reach normoxic levels, and body temperature tended to stabilize at a hypothermic value. Exposure to various levels of hypoxia produced graded suppression of shivering, with the result that the change in body temperature varied directly with inspired O2 concentration. Hypoxia appears to act on the central nervous system to suppress shivering and sinus nerve afferents appear to counteract this direct effect of hypoxia. In intact cats, this counteraction appears to be sufficient to maintain body temperature under hypoxic conditions at room temperature but not in the cold.


1998 ◽  
Vol 88 (9) ◽  
pp. 429-436 ◽  
Author(s):  
JR Montague ◽  
M Bovarnick ◽  
SC Effren ◽  
CC Southerland

To test the null hypothesis that limb dominance (laterality) and side of complaint are not associated in a diverse population, nearly 400 patients (40% male, 60% female) of varying age and body size from three South Florida podiatric medical teaching facilities were surveyed in 1995-1996. Radiographs of feet were available for 15% of the patients, and the metatarsus adductus angle was measured on each x-ray. The typical patient was a women (median age, 49 years) of average body weight and average body-mass index. No statistical association was found between laterality and side of complaint in the broader sample, although a significant association did appear in the subsample of patients with bilateral x-rays. The prevalence of metatarsus adductus deformity (metatarsus adductus angle &gt; 15 degrees) among patients with x-rays was 62%. No sex-specific, age-specific, or body size-specific associations were found between handedness and metatarsus adductus deformity.


2015 ◽  
Vol 22 (3) ◽  
pp. 143-147
Author(s):  
Arletta Hawrylak ◽  
Dorota Wojna ◽  
Krystyna Chromik

Abstract Introduction. Doing asymmetric sports when one suffers from body asymmetry may cause body posture disorders. The aim of the study was to assess the spinal and shoulder complex mobility of professionally trained volleyball athletes compared to that of their peers who do not practise any sports. Material and methods. The study involved 60 participants divided into two groups. Group 1 consisted of 30 girls aged 14 years. The average height in the group was 176.37 ± 6.29 cm, and the average body mass was 64.53 ± 7.12 kg. Group 2 consisted of 30 girls aged 15.6 ± 1.12 years who did not practise any sports. The average body height in this group was 159.37 ± 3.33 cm, and the average body mass was 51.83 ± 4.03 kg. The dominant limb was defined on the basis of lateralization. The spinal range of motion was measured by means of a Saunders digital inclinometer, and the shoulder complex range of motion was examined using the goniometric method. Means and standard deviations were calculated, and Student’s t-test was applied in order to determine the differences between the two groups. Results. The differences in the values obtained in the two groups for the spinal range of motion in the sagittal plane were statistically significant only for the range of lumbar spine bending and extension. It was found that group 1 had a higher range of spine mobility in the frontal and transverse planes, and the differences were statistically significant in all the assessed ranges towards the dominant limb. An analysis of the shoulder girdle range of motion in the groups revealed that the differences were also statistically significant in all of the examined ranges. Conclusion. Professional volleyball practice can cause an increase in spine flexibility in most of its ranges, and the shoulder girdle range of motion in female volleyball players can exceed population norms, especially for the upper dominant limb.


Obesities ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 167-177
Author(s):  
Hyunshik Kim ◽  
Jiameng Ma ◽  
Junghoon Kim ◽  
Daolin Xu ◽  
Sunkyoung Lee

There are few studies comparing adherence to Canadian 24-hour Movement Guidelines (24-h MG) before and during the COVID-19 pandemic and exploring the pandemic’s effect on childhood obesity. This survey-based 2-year study investigated changes in obesity and adherence to the 24-h MG in children before and during the COVID-19 pandemic. Data were collected at two points in time: pre-COVID-19 (May 2019; T1; n = 247) and during-COVID-19 (May 2021; T2; n = 171). Participants were healthy elementary school children aged between 6–12 years in northeastern Japan. The questionnaire comprised items on physical activity, screen time, sleep duration, adherence to the 24-h MG, and anthropometric and demographic characteristics. Among all participants, a statistically significant difference (p < 0.001) between the average body mass index at T1 (M = 16.06 kg/m2, SD = 2.08 kg/m2) and T2 (M = 18.01 kg/m2, SD = 3.21 kg/m2) was observed, where 17.8% were overweight and obese at T1 and 24% at T2, and 10.9% adhered to all 24 h MG at T1 and 4.1% at T2. To prevent obesity in children during the COVID-19 pandemic, environmental changes should be evaluated and appropriate preventive measures taken, including pro-community health programs that encourage parent-children outdoor activities.


2019 ◽  
Vol 96 (9) ◽  
pp. 896-899
Author(s):  
S. M. Rasinkin ◽  
Viktoriya V. Petrova ◽  
M. M. Bogomolova ◽  
E. P. Gorbaneva ◽  
A. G. Kamchatnikov ◽  
...  

The article presents results of a study of the thermal stability in athletes during specific activities in hot climate. This happened on a training camp at the sports center, located in the district Sredneakhtubinsky of the Volgograd region with the registration of climate indices. The study was conducted in July at an effective temperature +44,6° - +45,4°C. The study involved 6 athletes, representatives of athletics, sports category on the following candidate for master of sports. During the endurance, training (cross) in athletes showed a significant increase in the rectal temperature (RT), average skin temperature (AST), average body temperature (ABT) against the background of the gain in the heart rate. During the training as "repeated cuts", the increase in indices of the thermal state in athletes also persisted, but their values were significantly lower than on the cross. The comparison of the dynamics of indices of the thermal state with the level of sports skills of each athlete showed the following features: the smallest gain in the rectal temperature, average skin temperature and average body temperature observed in cross-country race was observed in sportsman, whose level of training coach the evaluated as a minimal in the group. The highest gain in indices of the thermal state at the cross happened in the athlete with an average fitness level. Optimal gain in such indices as RT, AST and ABT was observed in the most prepared athlete. There was revealed a high level of adaptationness of athletes to the exposure to high temperatures. This is confirmed by the data of the evaluation of dynamics of subjective evaluation of warmth sense modality in athletes during the study period.


Sign in / Sign up

Export Citation Format

Share Document