There some evidences that endocrine glands have marked influences on mast cells count The study was conducted to determine whether or not difference in mast cell count occurs in thymus gland of pincalectomized rats and to examine also sex difference in mast cell count under these condition adult Wistar rats were used. Pinealectomy was performed under light ether anesthesia. All animals were sacrificed by decapitation at 4 weeks after treatment. Samples were stained in Alcian-blue-PAS and, using Weibls multipurpose test system, the volume density (Vv), numerical density (Nv) and average volume of mastocytes were calculated. Analysis of morphometry has confirmed statistically significant increase in numerical density of mastocytes of pinealectomized female rats. The average volume of mastocytes has been also increased in both sex of animals after pinealectomy. The data from present studies show that there is marked sexual difference in reaction of mast cells after pinealectomy.

We have investigated the intramural blood vessels of the A-V segment in the conductive system of 20 human hearts using the method of light microscopy. The results of our study have shown that the A-V segment of the conductive heart muscles in human hearts has an abundant vascularisation. We have found the greatest density of the intramural net in the dorsal part of the A-V node; this density of blood vessels decreased toward the Hiss' bundle. After comparing these results with the earlier findings in the study of the intramural net in the S-A system we have found that A-V segment of the conductive heart system has a poorer blood supply in regard to S-A system. We have also found that the intramural net of blood vessels is weaker in the adjacent ventricular parts and in the interventricular septum. It cannot be said that there exists any surface vascular zone subepicardial, middle and deep sub-endocardiac--in the A-V segment of the conductive system of human heart.

Stereological characteristics of ductular parenchyma epithelial cells are analysed ultrastructurally on 8 cases of normal breast tissue. Different physiological states have been compared and tahat pre- and postovulatory. Volume density (VV), surface density (SV) and specific surface density (SV/VV) of nuclei and epithelial cells cytoplasm have been stereologically examined and compared. Postovulatory, the volume density (VV) and surface density (SV) of nuclei as well as specific surface density (SV/VV) of epithelial cells cytoplasm are much less, while a volume density (VV) of epithelial cells cytoplasm is greater.

The late effect of surgical ablation of the pineal gland on the morphometric changes of epithelial cells of rat thymus were investigated. The aim of this study was to determine a possible existence of sex related changes in the thymus epithelial cell after pinealectomy and to possibly clarify the correlation between the pineal gland and the thymus. Stereological ultrastructural parameters of the thymus cortical and medullar epithelial cells of male and female rats two months after pinealectomy are reported. A group of animals was submitted to surgery for ablation of pineal gland. The control group (shame-pinealectomized animals) underwent to the same surgical procedure but without removal of pineal gland. Animals were sacrificed 60th days after surgery. Para-sagittal thymus specimens were fixed by immersion in glutaraldehyde and processed for transmission electron microscopy. The volume and surface density (Vv, Sv) of nucleus and cytoplasm of cortical and medullar thymus epithelial cells were calculated using the Weibel's multipurpose test system and multilevel sampling technique on electron micrographs. Volume and surface density of mitochondria (Vvm, Svm), endoplasmic reticulum (Vvr, Svr), vacuole (Vvv) as well as numerical density of mitochondria (Nvm) were evaluated at different magnification levels. Our analysis confirmed a statistically significant increase in Vv of endoplasmic reticulum and vacuoles in both sex of pinealectomized rats. Sv of plasmalema, endoplasmic reticulum and mitochondrial membrane were markedly increased in thymus medullar epithelial cells of pinealectomized rats. Vv of mitochondria was significantly increased in cortical epithelial cells of pinealectomized animals. These results confirm that a correlation between pineal gland and thymus exists. However the present findings seem to support the concept of sex independent inhibitory action of pineal gland on thymus cortical and medullar epithelial cells.

The late effect of surgical ablation of pineal gland on the morphometric changes in epithelial cells of rat thymus were investigated. The aim of this study is to determine a possible existence of sex-different changes in composition of the epithelial cell component unit long after pinealecotmy what could be important for the subtle understanding of mutual correlation between pincal body and thymus. This article presents results of stereological ultrastructure parameters of thymuscortical and medullar epithelial cells of male and female rats two month after pinealectomy. The experimental animals were divide into two groups: an experimental one (pinealectomized) and the control group (shampinealectomized). Pinealectomized animals were submitted to surgical ablation of pineal gland while the control were undertaken the same surgical treatment but without removal of the pineal gland. Animals were sacrificed 60 th days following the surgery treatment. Parasagital pieces of thymus tissue were fixed by means of immersion in glutaraldehyde and prepared for transmission electron microscopy. Using Weibls multipurpose test system and multilevel sampling technique on electron micrographs the volume and surface density of nucleus (Vu, Sv) and cytoplasm of cortical and medullar thymus epithelial cells were calculated. At the different magnification level were established the volume and surface density of mitochondria (Vvm, Svm) endoplasmic reticulum (Vvr, Svr), vacoule(Vuv) as well as numerical density of mitochondria (Nvm). Our analysis has conformed statistically significant increase in Vv of reticulum and vacuole in both sex of pinealectomized rats. Sv of plasmalema, reticulum and mitochondrial membrane are markedly increased in thymus medullar epithelial cells of pienalectomized rats. Vv of mitochondria is significantly increased in cortical epithelial cells of pienalectomized animals. Results allow us to confirm that mutual correlation between pineal gland and thymus exists but present findings seem to support the concept of sex independent inhibitory action of pineal gland on thymus cortical and medullar epithelial cells.

The mammary glands of primigravid Wistar rats were investigated by stereological analysis in conditions of lead acetate administration via drinking water. The experiment was made in early summer period when absorbing ability of rat intestinum for lead is highest. Morphological state of glands was observed on 7th, 14th and 21st day of pregnancy. Groups of control animals were drinking deionized water but groups of experimental animals were drinking deionized water with added lead acetate. On paraffin sections coloured by HE method, volume density (VV) of glands structural elements were determined by multipurpose test system M42. Stereological analysis shows that lead diminishes the proliferative capacity of the mammary parenchyma and changes the morphofunctional differentiation of the overall structure in mammary gland during pregnancy. At the same time lead modifies quantitative trait of the mammary gland, i.e. the composition of the volume units in organ, without changing intramammary syncornization between the epithelium and lipocytes.

The aim of the study was to determine the effects of exogenous melatonin on Leydig cells in irradiation stress. Nuclear and cytoplasm surface of Leydig cells in sham pinealectomized and pinealectomized adult Wistar rats was determined after their total irradiation with 8 Gy of gama rays produced by 60 Co and with previously performed 14 days treatment by injecting of melatonin solution in a daily dose of 0.2 mg. Rats testes were histologically prepared 17 days after irradiation. Total melatonin administration significantly decreased surface of Leydig cells including both decrease of their nuclear and cytoplasm surface in irradiated sham pinealectomized and pinealectomized rats. The results suggested about direct effects of exogenous melatonin on Leydig cells in irradiation stress.

The effects of pinealectomy on the dynamics of morphometric changes in interdigitating cells(IDC) of rat thymus were investigated. The experimental animals were divided into two groups: an experimental one and the control group. Animals from the first group were subjected to pinealectomy while the second group were treated in the same manner, but without the removal of the pineal gland. All the animals were sacrificed 60. days following the surgery. The thymus tissue were fixed by means of immersion and prepared for transmission electron microscopy. Using Weibl's multipurpose test system and multilavel sampling technique on electron micrographs, the nuclear volume density(Vvn) and cytoplasmic volume density(Vvc) were calculated. At the different magnification level established the surface density(Sv) of nucleoid and cell membranes as wel as surface density of rough endoplasmic reticulum and mitochondrial membranes (Svm) and their volume density. Our analysis has confirmed statistically significant increase in Vv of the nucleus of pinealectomized rats. The average volumen of IDC has been also increased after pinealectomy as well as Vv, Nv and Sv of the mitochondria. The present findings seem to support the concept of inhibitory action of pineal gland on thymus IDC.