Morphology of the nutrient artery and its foramen in relation to femoral bone perfusion rates of laying and non‐laying hens

Author(s):  
Qiaohui Hu ◽  
Thomas J. Nelson ◽  
Roger S. Seymour
Author(s):  
Qiaohui Hu ◽  
Thomas J. Nelson ◽  
Roger S. Seymour

The metabolic rate of vertebrate bone tissue is related to bone growth, repair and homeostasis, which are all dependent on life stage. Bone metabolic rate is difficult to measure directly, but absolute blood flow rate (Q̇) should reflect local tissue oxygen requirements. A recent ‘foramen technique’ has derived an index of blood flow rate (Qi) by measuring nutrient foramen sizes of long bones. Qi is assumed to be proportional to Q̇, however, the assumption has never been tested. This study used fluorescent microsphere infusion to measure femoral bone Q̇ in anaesthetised non-laying hens, laying hens and roosters. Mean cardiac output was 338±38 ml min−1 kg−1, and the two femora received 0.63±0.10 % of this. Laying hens had higher wet bone mass-specific Q̇ to femora (0.23±0.09 ml min−1 g−1) than the non-laying hens (0.12±0.06 ml min−1 g−1) and roosters (0.14±0.04 ml min−1 g−1), presumably associated with higher bone calcium mobilization during eggshell production. Estimated metabolic rate of femoral bone was 0.019 ml O2 min−1 g−1. Femoral Q̇ increased significantly with body mass, but was not correlated with nutrient foramen radius (r), probably due to a narrow range in foramen radius. Over all 18 chickens, femoral shaft Q̇/r was 1.07±0.30 ml min−1 mm−1. Mean Qi in chickens was significantly higher than predicted by an allometric relationship for adult cursorial bird species, possibly because the birds were still growing.


2015 ◽  
Vol 118 (8) ◽  
pp. 980-988 ◽  
Author(s):  
Rhonda D. Prisby ◽  
Bradley J. Behnke ◽  
Matthew R. Allen ◽  
Michael D. Delp

Spaceflight and prolonged bed rest induce deconditioning of the cardiovascular system and bone loss. Previous research has shown declines in femoral bone and marrow perfusion during unloading and with subsequent reloading in hindlimb-unloaded (HU) rats, an animal model of chronic disuse. We hypothesized that the attenuated bone and marrow perfusion may result from altered vasomotor properties of the bone resistance vasculature. Therefore, the purpose of this study was to determine the effects of unloading on the vasoconstrictor and vasodilator properties of the femoral principal nutrient artery (PNA), the main conduit for blood flow to the femur, in 2 wk HU and control (CON) rats. Vasoconstriction of the femoral PNA was assessed in vitro using norepinephrine, phenylephrine, clonidine, KCl, endothelin-1, arginine vasopressin, and myogenic responsiveness. Vasodilation through endothelium-dependent [acetylcholine, bradykinin, and flow-mediated dilation (FMD)] and endothelium-independent mechanisms [sodium nitroprusside (SNP) and adenosine] were also determined. Vasoconstrictor responsiveness of the PNA from HU rats was not enhanced through any of the mechanisms tested. Endothelium-dependent vasodilation to acetylcholine (CON, 86 ± 3%; HU, 48 ± 7% vasodilation) and FMD (CON, 61 ± 9%; HU, 11 ± 11% vasodilation) were attenuated in PNAs from HU rats, while responses to bradykinin were not different between groups. Endothelium-independent vasodilation to SNP and adenosine were not different between groups. These data indicate that unloading-induced decrements in bone and marrow perfusion and increases in vascular resistance are not the result of enhanced vasoconstrictor responsiveness of the bone resistance arteries but are associated with reductions in endothelium-dependent vasodilation.


2002 ◽  
Vol 52 (2) ◽  
pp. 81-84
Author(s):  
B. Koréneková ◽  
A. Jacková ◽  
J. Kottferová ◽  
P. Siklenka ◽  
M. Skalická ◽  
...  
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2013 ◽  
Vol 22 (01) ◽  
pp. 46-51
Author(s):  
M. Rahnama ◽  
I. Jastrzêbska-Jamrogiewicz ◽  
R. Jamrogiewicz

Summary Objective: The aim of this study was to observe the variability of the level of copper, zinc and manganese in saliva amongst women with hypoestrogenia, treated and untreated with hormone replacement therapy (HRT). Methods: The study was conducted on a group of 60 women treated and untreated with HRT. Half of the patients were after natural menopause and other half was after surgical removal of ovaries. Research on micronutrients in non-stimulated saliva and blood serum was carried out in 2005. Tests on saliva were repeated in 2010. Investigation of bone mineral density (BMD) of femoral bone was performed in year 2010. Results: Statistical analysis of concentration of copper and zinc revealed a linear correlation between the levels of these microelements in blood serum and saliva. The study revealed that HRT has a beneficial effect on BMD and the concentration of copper and manganese in saliva and blood serum of patients after the menopause. Patients treated with HRT showed higher BMD values than groups not treated with hormones. Conclusions: Saliva appears to be a promising diagnostic material which can be used to analyze the content of trace elements, but further research should be carried out on a broader research group.


Intermittent Lighting Improves the Efficiency of Artificial Insemination in Cage Housed Laying Hens Kavtarashvili A.Sh., Kolokolnikova T.N. Federal Scientific Center “All-Russian Research and Technological Poultry Institute” of Russian Academy of Sciences Omsk Agrarian Scientific Center Summary: The effects of different lighting regimes on the oviposition schedule, productive performance, and reproductive efficiency in cage housed laying hens of layer parental flock (Hisex White-R) were studied; the reasonable regime of artificial insemination (AI) under intermittent lighting is proposed. It was found that intermittent lighting regime 1L:4D:4L:1D:4L:10D compared to the constant lighting significantly alters oviposition schedule: under this regime 82.3% of all daily eggs were laid until 9 am (vs. 66.6% in control). This regime and AI at 10 am improved the productive and reproductive performance compared to control (constant lighting 16L:8D and AI at 12 am): mortality by 1.9%, egg production per initial hen by 3.8%, egg weight by 1.1%, percentage of eggs suitable for incubation by 1.9%, egg fertility by 0.9%, hatchability by 2.3%, hatch of chicks by 2.9%, feed conversion ratio (kg of feed per 10 eggs) by 5.3%, the expenses of electric energy for lighting (per 1000 eggs suitable for incubation) by 54.5%. Key words: INTERMITTENT LIGHTING, CAGE HOUSED LAYERS, ARTIFICIAL INSEMINATION (AI), OVIPOSITION SCHEDULE, AI TIMING, PRODUCTIVE PERFORMANCE, REPRODUCTIVE PERFORMANCE


1974 ◽  
Vol 75 (1) ◽  
pp. 133-140 ◽  
Author(s):  
B. E. Senior

ABSTRACT A radioimmunoassay was developed to measure the levels of oestrone and oestradiol in 0.5–1.0 ml of domestic fowl peripheral plasma. The oestrogens were extracted with diethyl ether, chromatographed on columns of Sephadex LH-20 and assayed with an antiserum prepared against oestradiol-17β-succinyl-bovine serum albumin using a 17 h incubation at 4°C. The specificity, sensitivity, precision and accuracy of the assays were satisfactory. Oestrogen concentrations were determined in the plasma of birds in various reproductive states. In laying hens the ranges of oestrone and oestradiol were 12–190 pg/ml and 29–327 pg/ml respectively. Levels in immature birds, in adult cockerels and in an ovariectomized hen were barely detectable. The mean concentrations of oestrone and oestradiol in the plasma of four non-laying hens (55 pg/ml and 72 pg/ml respectively) and one partially ovariectomized hen (71 pg/ml and 134 pg/ml respectively) were well within the range for laying hens. It is evident that the large, yolk-filled follicles are not the only source of oestrogens in the chicken ovary.


Author(s):  
Benjamin C. Taylor ◽  
Jacob J. Triplet ◽  
David Bird Johnson ◽  
Barry Dale Sharpe ◽  
Brian Sullivan ◽  
...  
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