[Prolactin and somatotropin binding by granulosa cells of cows at different reproductive states]

Specific binding of bovine prolactin and somatotropin by granulosa cells from the antral follicles of various diameters was studied in cows at different reproductive states, prepubertal, pubertal, and early gestation. The ability of granulosa cells to bind prolactin did not depend on the reproductive state of an animal. At the same time, the dynamics of somatotropin specific binding by granulosa cells during maturation of the antral follicles differed at dissimilar reproductive states of the cows. When the diameter of follicles increased from 3-5 to 6-10 mm, specific binding of 125I-somatotropin decreased in pubertal animals, but remained unchanged in the prepubertal and pregnant animals. The results of Scatchard analysis of the binding data suggest that sexual maturation of cows did not affect the binding of prolactin and somatotropin by granulosa cells from follicles of 1-2 mm in diameter. The data obtained suggest that the decreased sensitivity of granulosa cells to somatotropin at the terminal stages of maturation of the antral follicles is essential for their development and acquisition of the ability for ovulation.

[Prolactin-binding activity of bovine granulosa cells on luteinization and exposure to somatotropin in vitro]

The influence of luteinization and bovine somatotropin (ST, 5-50 ng/ml) during cultivation of bovine granulosa cells on their ability to bind [125I]-labeled bovine prolactin (PRL) was studied. On the second day of cultivation in serumfree medium, granulosa cells from immature antral follicles underwent spontaneous luteinization, in both the absence and presence of ST. The level of [125I]-PRL specific binding to cells increased after two days of cultivation, with a negative correlation being revealed between estradiol production by the cells and their PRL-binding activity. At the same time, the addition of ST to the culture medium had no effect on the level of [125I]-PRL specific binding to native and luteinizing granulosa cells. The findings suggest a stimulatory influence of the luteal differentiation process on the PRL-binding activity of bovine granulosa cells, this influence is independent of the action of ST.

Characterization of somatotropin- and prolactin-binding sites on bovine granulosa cells using homologous hormones

Specific binding of bovine somatotropin (BST) and bovine prolactin (BPRL) to cow granulosa cells from antrum-containing follicles of different diameter was studied. Scatchard analysis of the data revealed a single type of low affinity BST-binding sites on the granulosa cells with dissociation constants similar to those for the BPRL-binding sites. The number of BST-binding sites on the cells decreased with increasing follicle diameter from 3-5 to 6-10 mm. However, the binding capacity to BPRL decreased only in the case of cells from follicles 11-20 mm in diameter. The findings are discussed in relation to the "homologous binding" phenomenon.

[Surgical, radiation and combined treatment of multiple primary malignancies of the respiratory system]

Surgery for primary multiple malignant tumors of the respiratory system was carried out in 141 patients. Reconstruction, plastic operations and sparing resections were performed in 79 cases (68.5%). Five-year survival after radical surgery was 43.8%.

[Reciprocal modulation of regulatory action of prolactin and somatotropin on DNA synthesis in granulosa cells of cows]

A comparative analysis of the individual and joint influence of bovine prolactin (BPRL) and bovine somatotropin (BST) on DNA synthesis in cultured bovine granulosa cells from follicles of 3-5 mm in diameter was conducted, and a possibility for regulation of BPRL binding to receptors on the cells by BST was examined. Despite a unidirectional growth-promoting action of BPRL and BST on granulosa cells, their joint mitogenic effect on the cells was not additive at low concentrations of BPRL. The addition of BST to the culture medium did not alter the biphasic character of dependence of DNA synthesis in the cells on BPRL concentration, but increased the maximum effective concentration of the latter. When culturing granulosa cells with BST, the absence of its influence on the level of BPRL specific binding to the cells was shown. This fact suggests that BST modulating action on the mitogenic effect of BPRL is not a result of a change in the number of free receptors for PRL on granulosa cells. The results obtained are discussed in relation to the notion of similarity of receptor functional properties and intracellular signal ways for PRL and ST.

[Neurochemical organization of the brain reinforcing systems]

Modern concepts of neurophysiological mechanisms of the brain reinforcing systems are reviewed from A.A. Ukhtomsky's concept of dominanta. The brain mesocorticolimbic system was shown to play a key role in functioning of the brain reinforcing systems. Morphological and neurochemical organisation of this system determining the emotional sphere, was studied. The dopamine system was found to be the main neurochemical tool of the mesocorticolimbic system. Other transmitters, neuromodulators, and hormones play a regulatory role in the latter. The data obtained corroborate the authors' concept of fluctuating emotional gradient.

[Malignant lymphoproliferative lesions of the trachea]

Detailed review of literature and analysis of 4 authors's cases of the trachea non-Hodgkin lymphoma and lymphogranulomatosis are presented.

[Primary melanoma of the respiratory tract]

4 cases of melanoma of the respiratory tract (trachea and bronchi) are analysed clinico-morphologically. A case of melanoma with a primary multiple location (trachea and the main bronchus), rapid recurrence after surgery and radiation therapy is described in detail. Melanocytic nature of the tumor is proved immunohistochemically.

Prolactin in follicular fluid and intracellular store calcium in follicular cells are related to morphological signs of ovarian follicle atresia in cows: work in progress

It is known that prolactin (PRL) is the third pituitary hormone serving gonadotropic function in mammals. However, its role in the regulation of ovarian folliculogenesis and, in particular, its relationship to follicular atresia as well as the mechanism of its influence on follicular cells are poorly understood. We investigated PRL levels in follicular fluids (FFs) and intracellular store calcium ([Ca2+]is) in cell walls of bovine ovarian follicles with diameters of 10 to 20 mm and their relationship to follicular atresia. Ovarian follicles were categorized on the basis of macroscopic criteria and of microscopic examination of granulosa cell (GC) smears. Prolactin concentrations in FFs were measured by RIA and levels of [Ca2+]is in follicular cells were determined by using the fluorophore chlortetracycline. Compared to atretic follicles, morphologically normal follicles were characterized by higher concentrations of PRL in FFs (P < 0.001) and lower contents of [Ca2+]is in follicular cells (P < 0.01). Furthermore, follicles containing no more than 20% of pycnotic GCs had higher levels of PRL in their fluids than those containing over 40% of pycnotic GCs (P < 0.05). Finally, the direct effect of PRL on [Ca2+]is content in follicular cells was studied in vitro. Compared to control, PRL decreased (P < 0.001) the levels of [Ca2+]is in the cells after 24 h culture of follicular walls from morphologically normal follicles in TCM 199 supplemented by 10% fetal calf serum. Our findings suggest that the decline of PRL concentrations in FFs and the rise of [Ca2+]is contents in follicular cells are related to atresia of large bovine follicles and that there appears to be a relationship between the two biochemical parameters.

[Changes in the content of prolactin and somatotropin and the level of their binding with cells in the growing antral follicles of cows]

The hormone concentrations in the follicular fluid rise along with an increase in follicular diameter whereas the level of their binding to cells declines. The findings suggest that two basic parameters characterizing the degree of prolactin and somatotropin actions on granulosa cells develop in different directions in the course of antral follicle maturation.

[The dynamics of the somatotropin content in the follicular fluid during maturation and atresia of the antral follicles in bovine ovaries]

Somatotropin level was shown to rise in follicular fluid from bovine ovaries during the follicular growth stage with increasing of the follicular diameter from 3-5 to 6-10 mm. Follicles with the diameter of 10-20 mm containing over 40% of pycnotic granulosa cells revealed lower levels of somatotropin in their fluid as compared with those containing 20% or lesser amount of pycnotic cells. The data obtained suggest a direct involvement of somatotropin in regulation of the growth and atretic processes in antral bovine ovarian follicles.