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A number of experiments have shown that only few among the follicles which start growing, are ovulable while the rest become atretic. In the regulation of atresia process primarily gonadotropins and steroids participate as well as many other growth factors. Recent studies have demonstrated that apoptosis of granulosa cells is one of the main factors responsible for follicular atresia. It is believed that in programmed granulosa cell death a decisive role is played by secondary messenger signal cells. It was also shown, that apoptosis of granulosa cells can be initiated by disturbances of metabolism cAMP. In the process this will reach to the expression of genes responsible for degenerative changes of a cell leading to its death. The course of apoptosis of granulosa cells is characterized by similar morphological and biochemical changes which accompany apoptosis of other types of cells. These changes constitute one of the processes initiating changes of structural ovarian follicles. Programmed death of granulosa cells is therefore another piece of evidence, that apoptosis is a physiological process regulating tissue regression and reconstruction.
The research objective was to demonstrate the course of Vitamin C synthesis process in geese from the 1st to the 56th day of life as compared to the growth of organ and body mass. The level of Vitamin C was determined according to Roe-Kuethers method in the glandular stomach, jejunum, kidneys and spleen. It was proved that in geese in their embrional stage, the greatest amount of Vitamin C was synthesized by the kidneys - 214.5 mg/kg tissue, then the spleen - 212.6 mg/kg, a slighty lesser amount by the glandular stomach - 154.0 mg/kg and by the jejunum - 148.5 mg/kg tissue. In the first 56 days of life, the glandular stomach synthesized about 220 mg/kg tissue Vitamin C. The body mass growth was higher than glandular stomach mass (51.64 times and 15.91 times). It should be stated that the glandular stomach in this time period provides less and less Vitamin C. Intensive renal, spleen and jejunum mass growth (175.4 times, 380 times and 59.94 times respectively) caused a considerable increase of the Vitamin synthesis by the whole organs.
The development of the yellow body and ovarial vesicles was evaluated in 20 cows during an entire oestrus cycle (group II, n = 9) and an oestrus ended by pregnancy (group I, n = 11) using a linear ultrasonograph (5 MHz). The investigations were performed on the first day of oestrus and then on the 5, 12 and 18 day after oestrus. The maximum diameter of the yellow body was noted on the 12th day of the oestrus cycle. At the same time (depending on the phase of oestrus) 25 (40%) of the yellow bodies possessed a vesicle situated internally. This phenomenon did not affect either the length of oestrus or the effects of insemination. At the same time in the group of pregnant cows the size of the yellow body with a vesicle was on the 12th day significantly larger than in group II (p < 0,05). A large vesicle was observed with a similar frequency in both groups of cows in 30, 50 and 75% of the animals on the 5, 12 and 18 day of the cycle, respectively. The large size of the vesicle observed on the 5th day of oestrus suggests that it is a vesicle which dominates the first period of growth of the ovarial vesicles.
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