Fixed patterns of bradycardia during late embryonic development in domestic fowl with C locus mutations

1995 ◽  
Vol 268 (1) ◽  
pp. H56-H60 ◽  
Author(s):  
R. S. Howe ◽  
W. W. Burggren ◽  
S. J. Warburton
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Embryonic Development ◽  
Structural Gene ◽  
Domestic Fowl ◽  
Embryonic Mortality ◽  
White Leghorn ◽  
Equivalent Rate ◽  
Mutant Strains ◽  
White Leghorns

A predictable late embryonic bradycardia (relative to normal White Leghorn chickens) has been documented in chicken strains with C locus mutations. The basis of the bradycardia remains unknown but clearly is related to a mutation at the C locus, which contains the structural gene for tyrosinase. When compared with the heart rate of normal White Leghorns (approximately 295–305 beats/min from day 8 to day 20 of incubation), ca/ca and other C locus mutants showed a 10–12% reduction in heart rate during the last 4 days of incubation. Embryonic mortality occurred in both mutant and normal strains at an equivalent rate (approximately 23%); a significant bradycardia (when compared with surviving embryos of the same strain) developed on the day before death in White Leghorn but not mutant strains. The bradycardia did not affect embryonic oxygen consumption (approximately 0.2 ml O2.egg-1.min-1 at day 14 and 0.4 ml O2.egg-1.min-1 at day 20), which showed only minor differences between strains that can be attributed to differences in embryonic mass on days 16–20.

Metabolic adaptation of the chick embryo to chronic hypoxia

1975 ◽  
Vol 228 (5) ◽  
pp. 1346-1350 ◽  
Author(s):  
J Beattie ◽  
AH Smith
Keyword(s):  
Oxygen Consumption ◽  
High Altitude ◽  
Sea Level ◽  
Domestic Fowl ◽  
Chronic Hypoxia ◽  
Metabolic Adaptation ◽  
White Leghorn ◽  
Consumption Rates ◽  
Successive Generations ◽  
Late Embryo

In a colony of white leghorn chickens maintained at 3,800 m successive generations exhibited an increasing hatchability of fertile eggs incubated at elevation of 3,100m. Embryonated eggs produced by the high-altitude-adapted line (WM) and by genetically similar but unselected stocks at sea level (D) were incubated at 3,100 m and at sea level, and the oxygen consumption was measured on individual eggs after the 17th day of incubation. At sea level, oxygen consumption rates of WM strain were less than that of SL stocks during late embryonic development. At 3,100 m, embryonic respriation of all strains was reduced, but to a much lesser degree in the high-altitude strain. It appears that a decreased metabolic activity of the late embryo coupled with a slower rate of embryonic developement is an important factor in the adaptation of the domestic fowl to high altitude.

Tissue Interactions in Scale and Feather Development as Studied in Dermal-Epidermal Recombinations

Development ◽  
1963 ◽  
Vol 11 (4) ◽  
pp. 765-789
Author(s):  
Mary E. Rawles
Keyword(s):  
Domestic Fowl ◽  
White Leghorn ◽  
Tissue Interactions ◽  
White Leghorns ◽  
Unusual Phenomenon ◽  
The Common ◽  
Feather Development

The foot of developing embryos of scalefooted varieties of the common domestic fowl (Silver Campine, White Leghorn and others) frequently exhibits feather primordia emerging from the scales of various regions. Many of the feather germs are rudimentary and disappear by the time of hatching, but some persist and differentiate into normal feathers. Such feathers are often inconspicuous and easily overlooked (Plate 1, figs. I–M). Scales bearing feathers by no means represent an unusual phenomenon. Indeed, they were clearly identified by many of the earlier workers, particularly those interested in homologizing these two specialized epidermal derivatives (Jefferies, 1883; Davies, 1889; Bornstein, 1911; Blaszyk, 1935). More recently, the frequent association of feathers with the scales of those pedal components (digits) which arise from the wing ectoderm, after implantation of mesoderm from the prospective foot region, has been noted by Saunders, Cairns & Gasseling (1957) working with White Leghorns.

scholarly journals Variance and covariance component analysis of incubational mortality in chickens

1999 ◽  
Vol 42 (3) ◽  
pp. 295-302
Author(s):  
G. S. Brah ◽  
J. S. Sandhu ◽  
M. L. Chaudhary
Keyword(s):  
Embryonic Development ◽  
Genetic Correlations ◽  
Component Analysis ◽  
Embryonic Mortality ◽  
White Leghorn ◽  
Late Mortality ◽  
Covariance Component ◽  
Three Components

Abstract. A total of 1,33,507 eggs obtained from 7864 pullets of two selected White Leghorn strains over four generations representing 304 sires and 1669 dams were incubated. The unhatched eggs were broken-open for examination of embryonic development and classified as early-dead (0-11d), late-dead (12-22d) and pips. The sire component heritabilities (%) pooled over years in the two strains, respectively were 10.5±3.4 and 11.0±3.2 for total incubation mortality; 2.2 ± 2.2 and 5.1 ± 2.4 for early-dead; 6.8 ± 3.0 and 8.0 ± 3.0 for late-dead and 8.7 ± 3.1 and 4.8 ± 2.4 for pips. Total embryonic mortality as well as its three components had high genetic correlations amongst each other. However, the genetic correlations of pipping mortality with early and late mortality were weaker as compared with those of early and late mortality.

CARDIORESPIRATORY SYSTEM UNDER BICYCLE ERGOMETER TEST IN SKIERS WITH DIFFERENT TRAINING STATUS (KOMI REPUBLIC)

2019 ◽  
pp. 76-84
Author(s):  
Yu.G. Solonin ◽  
T.P. Loginova ◽  
I.O. Garnov ◽  
A.L. Markov ◽  
A.A. Chernykh ◽  
...  
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Komi Republic ◽  
Rate Pressure Product ◽  
Training Status ◽  
Maximum Oxygen Consumption ◽  
Bicycle Ergometry ◽  
Cardiorespiratory System ◽  
Unit Pulse ◽  
Ski Racers

The aim of the study is to examine the impact of training status on ski racers (Komi Republic) at rest and under bicycle ergometry evaluating their cardiorespiratory system parameters. Materials and Methods. The authors examined male ski racers with different training status: 22 first-rank sportsmen, 22 candidates for Master of Sports and 22 Masters of Sports. Athletes underwent bicycle ergometry loads up to refusal. Oxycon Pro system (Germany) was used. Then authors studied the complex of cardiorespiratory parameters, calculating maximum oxygen consumption and unit physiological cost. Results. At rest and under standard physical load (200 W) Masters of Sports demonstrate significantly increased training status among ski racers in such cardiorespiratory system parameters as heart rate, rate pressure product and oxygen pulse. Under standard physical load (200 W) statistically significant differences between first-rank sportsmen and candidates for Master of Sports are detected by heart rate, rate pressure product, respiration rate, respiratory minute volume and oxygen utilization coefficient. Such deviations indicate differences in training status. Under maximum load, the highest training status is found in Masters of Sports: bicycle ergometry load power and duration; unit pulse, pressor and cardiac cost, bulk and unit values of maximum oxygen consumption. Heart rate values, unit pulse and heart-vent cost indicate a high training status in candidates for Master of Sports under load up to refusal, if compared with first-rank sportsmen. Athletes’ organism under load up to refusal works more efficiently than under moderate load (200 W). The training status in ski racers (Komi Republic) is manifested in the saving cardiorespiratory system functions, both at rest and under standard bicycle ergometry, as well as in parameters of unit physiological cost under loads up to refusal and increased values of maximum oxygen consumption. Keywords: ski racers, Komi Republic, training status, bicycle ergometry loads, cardiorespiratory system, maximum oxygen consumption.

Accuracy of the Heart Rate Index Equation to Assess Oxygen Consumption in Obese Patients

2014 ◽  
Vol 46 ◽  
pp. 169-170
Author(s):  
Roger L. Sacks ◽  
Barry Franklin ◽  
Judy Boura ◽  
James Van Loon
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Obese Patients

alpha-Adrenergic control of oxygen delivery to myocardium during exercise in conscious dogs

1982 ◽  
Vol 242 (5) ◽  
pp. H805-H809 ◽  
Author(s):  
G. R. Heyndrickx ◽  
P. Muylaert ◽  
J. L. Pannier
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Coronary Blood Flow ◽  
Coronary Sinus ◽  
Oxygen Delivery ◽  
Left Ventricular ◽  
Conscious Dogs ◽  
Adrenergic Blockade ◽  
Adrenergic Control

alpha-Adrenergic control of the oxygen delivery to the myocardium during exercise was investigated in eight conscious dogs instrumented for chronic measurements of coronary blood flow, left ventricular (LV) pressure, aortic blood pressure, and heart rate and sampling of arterial and coronary sinus blood. After alpha-adrenergic receptor blockade a standard exercise load elicited a significantly greater increase in heart rate, rate of change of LV pressure (LV dP/dt), LV dP/dt/P, and coronary blood flow than was elicited in the unblocked state. In contrast to the response pattern during control exercise, there was no significant change in coronary sinus oxygen tension (PO2), myocardial arteriovenous oxygen difference, and myocardial oxygen delivery-to-oxygen consumption ratio. It is concluded that the normal relationship between myocardial oxygen supply and oxygen demand is modified during exercise after alpha-adrenergic blockade, whereby oxygen delivery is better matched to oxygen consumption. These results indicate that the increase in coronary blood flow and oxygen delivery to the myocardium during normal exercise is limited by alpha-adrenergic vasoconstriction.

Respiratory Metabolism During Pregnancy in the Guinea Pig

1957 ◽  
Vol 190 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Richard M. Hoar ◽  
William C. Young
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Guinea Pig ◽  
Metabolic Rate ◽  
Adrenal Cortex ◽  
Guinea Pigs ◽  
Sharp Decrease ◽  
Zona Fasciculata ◽  
Respiratory Metabolism ◽  
Morphological Differences

Oxygen consumption and heart rate during pregnancy were measured in untreated, thyroxin-injected and thyroidectomized guinea pigs given I131. From impregnation until parturition, oxygen consumption increased 7.9% in untreated females. The increase continued until 5 days postpartum when a sharp decrease occurred. The increase is not accounted for by growth of the fetal mass. Comparable increases occurred in thyroxin-injected (16.2%) and thyroidectomized (11.9%) females, although the levels throughout were higher and lower, respectively, than in intact females. Heart rate did not increase. On the contrary, statistically significant decreases occurred in the untreated and thyroxin-injected females. Although the mechanism associated with the increased metabolic rate is not known, the possibility of thyroid participation would seem to be excluded. Involvement of the adrenal cortex is suggested by morphological differences in the cells of the zona fasciculata in pregnant and nonpregnant females and by evidence cited from other studies.

The validity of the use of heart rate in estimating oxygen consumption in static and in combined static/dynamic exercise

Ergonomics ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 141-148 ◽  
Author(s):  
S. MAAS ◽  
M. L. J. KOK ◽  
H. G. WESTRA ◽  
H. C G. KEMPER
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Dynamic Exercise
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