Content of retinol and retinyl esters in blood plasma, liver, kidney and reproductive organs of Japanese quails

2002 ◽  
Vol 50 (4) ◽  
pp. 435-443 ◽  
Author(s):  
Annamária Kerti ◽  
Ingeborg Buchholz ◽  
F. J. Schweigert

Due to its importance in many physiological processes such as cell proliferation and differentiation, vitamin A plays a key role in reproduction. The present study examines the content and distribution of retinol and retinyl esters in the blood plasma, liver, kidney, ovary and oviduct (infundibulum, magnum, isthmus and uterus) of the laying Japanese quail. (1) The results show that the stage of egg laying had no influence on the level of vitamin A (retinol or retinyl esters) in plasma, kidney and liver. (2) The results further indicate that in the oviduct there are quantitative and qualitative differences in the concentration of retinol and retinyl esters, but that these differences are not altered by the stage of egg formation. (3) The highest levels of vitamin A in the isthmus and uterus were associated with a predominance of retinyl esters (palmitate and stearate); sections with lower total levels of vitamin A (infundibulum, magnum) had retinol as the more dominant form of vitamin A. (4) Changes in the ratio of retinol to retinyl esters in the various sections of the avian oviduct might point to metabolic differences. The storage of vitamin A might therefore be the predominant function of the uterus and isthmus; in the infundibulum and magnum, where vitamin A is predominantly present as retinol, vitamin A serves rather as a precursor for the modulation of the cellular metabolism of these structures.

Author(s):  
A. A. Kretov

The primary cause of injuries and inflammation of the reproductive system in female quails in industrial quail farming is the process of egg formation and its passage through the oviduct. With technological injuries females aged from 42 to 55 days are involved into the risk zone, whose weight of laid eggs ranges from 11,6 to 13,7 g. In previous morphological and histological studies, the following patterns of development of the organs of the reproductive system of quails under conditions of intensive technology have been established. The development of the reproductive organs of female quails of Japanese breed proceeds sequentially in seven periods: the first (1–21 days) is the period of relative rest of the growth of organs, the second (21–35 days) is the period of intensive morphogenesis of the ovaries and oviduct departments, the third (35–45 days) is the period of preparation and the beginning of egg laying, the fourth (45–75 days) is the period of egg laying growth or functional formation of the oviduct departments, the fifth (75–185 days) is the period of intensive folliculogenesis and high secretory activity of the departments of the oviduct or the peak of egg production, the sixth (185–200 days) is the beginning of the involution of the reproductive organs and a decrease in the rate of egg production, the seventh (200 days and older) is the involution of the reproductive organs and the termination of egg laying. Taking into account these patterns of development of the reproductive organs of quails, the feeding scheme of female egg quails has been adjusted, which provides for the division of the productive period into 4 phases: phase 1 is the beginning of egg production (36–45 days), phase 2 is the growth of egg production (46–75 days), phase 3 is the peak of egg production (76–185 days) and phase 4 is the decline of egg production (185–200 days). The proposed scheme of phase feeding of female quails of Japanese breed during the productive period is the advantageous technological technique, since it allows to reduce the injuries of the poultry oviduct and improve the quality indicators of the quail egg, as a result of reducing the weight and size of eggs in the initial phase of egg production and the number of large eggs during the entire productive period. The use of the new scheme of phase feeding of female quails of Japanese breed allows us to get more egg mass by 67,5 kg, due to the increase in the gross harvest of commercial quail eggs by 4,5 % and the livability of the quails by 5,6 %.


2000 ◽  
Vol 70 (3) ◽  
pp. 84-91 ◽  
Author(s):  
Florian Schweigert ◽  
Volker Bok

Dogs differ from other species with respect to the occurrence of a high percentage of retinyl esters in blood plasma and the excretion of substantial amounts of vitamin A in the urine. Our investigation focussed on the effects of different concentrations of vitamin A in the diet, ranging from concentrations below NRC requirements of 25 IU/kg body weight (BW) to 2400 IU/kg BW, on the levels of retinol and retinyl esters (palmitate/oleate and stearate) in canine blood plasma and urine. The plasma levels of retinyl esters paralleled the levels of vitamin A in the feed (r = 0.91; p < 0.001). The highest plasma level (12.1 ± 0.4 mg/l) was observed at the highest level in the diet. This observation may be explained by the fact that in dogs retinyl esters are associated with lipoproteins. Even under prolonged feeding on vitamin A levels below NRC requirements, retinyl esters were still present in the plasma (2.8 ± 0.1 mg/l). Levels of retinol were not affected (1.2 ± 0.03 vs. 1.0 ± 0.03 mg/l, respectively). In the urine, the concentration of retinol and retinyl palmitate/oleate increased with the first increase of vitamin A in the diet to 1.2 ± 0.4 mg/l of total vitamin A. Urinary levels were elevated and fluctuated with up to four peaks while dietary vitamin A levels were above NRC requirements. But the amount of retinol and retinyl esters excreted did not show any dependence on the amount of vitamin A in the diet. When the amount of vitamin A in the diet was at or below requirements, only traces of retinol and retinyl esters were detected in urine. Thus, contrary to current knowledge for most other mammals, retinyl ester levels in plasma and retinol and retinyl esters in the urine of dogs proved to be clearly but differently affected by the amount of vitamin A supplied with the diet. Contrary to retinol, plasma levels of retinyl esters closely reflect the actual supply of vitamin A with the feed. The occurrence of retinol and retinyl esters in urine may, however, be due to dietary supply of vitamin A in excess of standard requirements, thereby providing a useful indicator of a dietary supply of vitamin A above requirement. The mechanism involved in the possible regulation of urinary excretion of retinol and retinyl esters remains to be elucidated.


2017 ◽  
Vol 6 (7) ◽  
pp. R121-R130 ◽  
Author(s):  
J Brossaud ◽  
V Pallet ◽  
J-B Corcuff

Vitamin A (retinol) is a micronutrient critical for cell proliferation and differentiation. In adults, vitamin A and metabolites such as retinoic acid (RA) play major roles in vision, immune and brain functions and tissue remodelling and metabolism. This review presents the physiological interactions of retinoids and endocrine tissues and hormonal systems. Two endocrine systems have been particularly studied. In the pituitary, retinoids target the corticotrophs with a possible therapeutic use in corticotropinomas. In the thyroid, retinoids interfere with iodine metabolism and vitamin A deficiency aggravates thyroid dysfunction caused by iodine-deficient diets. Retinoids use in thyroid cancer appears less promising than expected. Recent and still controversial studies investigated the relations between retinoids and metabolic syndrome. Indeed, retinoids contribute to pancreatic development and modify fat and glucose metabolism. However, more detailed studies are needed before planning any therapeutic use. Finally, retinoids probably play more minor roles in adrenal and gonads development and function apart from their major effects on spermatogenesis.


2020 ◽  
Vol 3 (2) ◽  
pp. 216-242 ◽  
Author(s):  
Mayuri Shukla ◽  
Areechun Sotthibundhu ◽  
Piyarat Govitrapong

The revelation of adult brain exhibiting neurogenesis has established that the brain possesses great plasticity and that neurons could be spawned in the neurogenic zones where hippocampal adult neurogenesis attributes to learning and memory processes. With strong implications in brain functional homeostasis, aging and cognition, various aspects of adult neurogenesis reveal exuberant mechanistic associations thereby further aiding in facilitating the therapeutic approaches regarding the development of neurodegenerative processes in Alzheimer’s Disease (AD). Impaired neurogenesis has been significantly evident in AD with compromised hippocampal function and cognitive deficits. Melatonin the pineal indolamine augments neurogenesis and has been linked to AD development as its levels are compromised with disease progression. Here, in this review, we discuss and appraise the mechanisms via which melatonin regulates neurogenesis in pathophysiological conditions which would unravel the molecular basis in such conditions and its role in endogenous brain repair. Also, its components as key regulators of neural stem and progenitor cell proliferation and differentiation in the embryonic and adult brain would aid in accentuating the therapeutic implications of this indoleamine in line of prevention and treatment of AD.   


1956 ◽  
Vol 15 (2) ◽  
pp. 400-406
Author(s):  
I. R. Sibbald ◽  
J. P. Bowland ◽  
R. T. Berg

2020 ◽  
Vol 22 (1) ◽  
pp. 168-175 ◽  
Author(s):  
Lin-Jun Sun ◽  
Chong Li ◽  
Xiang-hao Wen ◽  
Lu Guo ◽  
Zi-Fen Guo ◽  
...  

Background:: Icariin (ICA), one of the main effective components isolated from the traditional Chinese herb Epimedium brevicornu Maxim., has been reported to possess extensive pharmacological actions, including enhanced sexual function, immune regulation, anti-inflammation, and antiosteoporosis. Methods:: Our study was designed to investigate the effect of ICA on cell proliferation and differentiation and the molecular mechanism of OPG/RANKL mediated by the Estrogen Receptor (ER) in hFOB1.19 human osteoblast cells. Results:: The experimental results show that ICA can stimulate cell proliferation and increase the activity of Alkaline Phosphatase (ALP), Osteocalcin (BGP) and I Collagen (Col I) and a number of calcified nodules. Furthermore, the mRNA and protein expression of OPG and RANKL and the OPG/ RANKL mRNA and protein expression ratios were upregulated by ICA. The above-mentioned results indicated that the optimal concentration of ICA for stimulating osteogenesis was 50ng/mL. Subsequent mechanistic studies comparing 50ng/mL ICA with an estrogen receptor antagonist demonstrated that the effect of the upregulated expression is connected with the estrogen receptor. In conclusion, ICA can regulate bone formation by promoting cell proliferation and differentiation and upregulating the OPG/RANKL expression ratio by the ER in hFOB1.19 human osteoblast cells.


Sign in / Sign up

Export Citation Format

Share Document