Identifications of radioactive steroid estrogen conjugates in blood plasma of laying hens after intramuscular injection of [4-14C]-es tr one

Steroids ◽  
1975 ◽  
Vol 25 (5) ◽  
pp. 677-695 ◽  
Author(s):  
A.H-H. Chan ◽  
A.R. Robinson ◽  
R.H. Common
Reproduction ◽  
2003 ◽  
pp. 739-751 ◽  
Author(s):  
HE Paczoska-Eliasiewicz ◽  
A Gertler ◽  
M Proszkowiec ◽  
J Proudman ◽  
A Hrabia ◽  
...  

Thirty-four-week-old laying hens received injections of recombinant chicken leptin to assess the role of leptin in avian ovarian function. In the first experiment, the hens (n=60) were divided into three groups: (i). fed ad libitum; (ii). fasted; and (iii). fasted + leptin. Hens were fasted for 5 days and those treated with leptin received 250 microg leptin kg-1 body weight twice a day, i.p. In the second experiment, the hens (n=72) were divided into four groups: (i). fed ad libitum; (ii). fasted; (iii). fasted + leptin given only during fasting (5 days); or (iv). fasted and leptin given during both fasting and 5 days of re-feeding (10 days). LH was measured in blood plasma, and progesterone and oestradiol were measured in blood plasma and the ovary by radioimmunoassay. Apoptosis was examined in the walls of the three largest yellow hierarchical follicles (F3-F1; F3 25-35 mm) by the TdT-mediated dUTP nick-end labelling method. Results showed that the injections of leptin during fasting: (i). delayed cessation of egg laying; (ii). attenuated regression of yellow hierarchical follicles; (iii). altered ovarian steroidogenesis; and (iv). abolished the fasting-induced apoptosis in the wall of F3-F1 follicles during the first 2 days of fasting and partially attenuated apoptosis after 5 days of fasting. Prolongation of leptin injections into the re-feeding period considerably delayed the restoration of the ovary. Expression of leptin receptor in laying hens was determined by RT-PCR. The highest expression of leptin receptor was observed in the hypothalamus. Lower receptor mRNA expression was found in the hypophysis, whereas the lowest expression was observed in the ovary. Within the ovary, a relatively high expression of leptin receptor was found in the stroma with cortical follicles <1 mm, the wall of white (1-8 mm) and small yellow follicles (>8-12 mm), and the granulosa layer of F3 follicles. The expression of leptin receptor in the granulosa layer of F2 and F1 follicles was barely detectable. This was in contrast to a much higher expression of leptin receptor maintained in the theca layer of F3-F1 follicles. The present results indicate that in chickens leptin might be involved in the adaptation to starvation due to attenuation of follicular apoptosis. The presence of leptin receptors in the ovary indicates the possibility of a peripheral effect of the hormone.


2011 ◽  
Vol 11 (4) ◽  
pp. 507-520 ◽  
Author(s):  
Andrzej Sechman ◽  
Mirosława Staruszczak ◽  
Janusz Rząsa

Comparison of Sex Steroid Concentration in Blood Plasma and Ovarian Follicles of White Leghorn and Greenleg Partridge Laying HensThe study was performed to compare plasma and ovarian levels of progesterone (P4) and estradiol (E2) with laying rate in two different breeds of egg-type chickens, i.e. White Leghorn (WL) and Greenleg Partridge (GP). Thirty-five-week-old WL (line H22; n = 8) and GP (line Z11; n = 8) hens were used in the experiment. Blood samples were collected from hens at the time of C1 oviposition (i.e. 0.5 h before C2 ovulation), then at 20, 16, 12, 8, 4, 2 h before C3 ovulation, and at the time of predicted C3 ovulation (i.e. just after C2 oviposition). On the following day, six birds of each breed were decapitated 2 h before ovulation on the next day after the last blood collection. A stroma, small (SWF; 1-4 mm), medium (MWF; 4-6 mm) and large (LWF; 6-8 mm) white prehierarchical follicles, and yellow hierarchical (F6-F1; 8-36 mm) ovarian follicles were isolated. P4 and E2 levels in blood plasma and ovarian follicles were determined radioimmunologically. The average rate of lay in WL hens was significantly higher than in GP hens (P<0.05). The highest concentrations of P4 and E2 were found 4 h before ovulation in both WL and GP hens. In WL hens the levels of P4 at the time of oviposition and at 4 and 2 h before ovulation were significantly higher in comparison with GP hens (P<0.05). On the other hand, higher E2 concentrations were found in GP hens at the time of oviposition and 12, 8 and 4 h before ovulation (P<0.05). In LWF and hierarchical follicles of WL hens the level of P4 was significantly lower than in GP hens (P<0.05). With respect to E2, a reverse relationship was observed in LWF and F6-F4 follicles. In conclusion, the results obtained indicate that in egg-type layers the profiles of plasma and ovarian sex steroids depend on their genotype. The significant differences in sex steroid levels in blood and ovarian follicles of the WL and GP breeds may contribute to explain the endocrinological factors that determined their laying performance and productivity.


2016 ◽  
Vol 05 (Special issue 1) ◽  
pp. 17-19
Author(s):  
Aleš Pavlík ◽  
Petr Sláma ◽  
Lenka Mazalová ◽  
Eliška Kabourková

Author(s):  
A. V. Lizarev ◽  
V. A. Pankov

When exposed to noise and vibration in experimental animals there was a decrease in the content of threeiodinethyronine, thyroxin and adrenocorticotropic hormone in blood plasma after 15 and 30 days of experience. An increase in loads led to an increase in the level of threeiodinethyronine and thyroxin under vibration exposure and was normalized with noise. The content of adrenocorticotropic hormone leveled in both cases.


1950 ◽  
Vol 162 (1) ◽  
pp. 182-188 ◽  
Author(s):  
J. H. Meyer ◽  
R. R. Grunert ◽  
Marie T. Zepplin ◽  
R. H. Grummer ◽  
G. Bohstedt ◽  
...  

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