Method for Determining Microcirculatory Hemodynamics by Laser Speckle Interferometry in Small Animals.

We performed experimental evaluation of various positions (ear, paw, and tail) of the of dynamic light scattering sensor of near-infrared laser radiation (840 nm) using speckle interferometry in rats. Dynamic monitoring of the reactions to prolonged ultrasound exposure (7 days) showed that the base of the tail is most suitable for this purpose. Additionally, analysis of microcirculation parameters on the surface of skin autograft was performed. The method of analysis of hemodynamics in humans was adapted for animals.

Effect of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the morphology of the thymus in hypophysectomized young and old birds.

Investigations were carried out on chicks of different age. It was found that the most pronounced changes in the morphology of the thymus occurred after neonatal hypophysectomy. These changes are least pronounced in old chicks. Peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly synthesized on the basis of amino acid composition of peptide complexes of the anterior and posterior pituitary lobes administered to hypophysectomized birds regardless of age promoted recovery of the morphological structures of the thymus. The anterior pituitary peptide (Lys-Glu-Asp-Gly) had more pronounced effect on the recovery of thymic structure than posterior pituitary peptide (Ala-Glu-Asp-Gly).

[Effects of Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly peptides on hormonal activity and thyroid morphology in hypophysectomized mature and old birds].

The aim of the paper was to investigate effects of Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly peptides which were designed and synthesized on the basis of amino acid study of the hypophyseal anterior and posterior lobe peptides on the thyroid morphology and hormonal activity in mature chicken and old birds. Hypophysectomy was established to produce atrophic changes in the thyroid gland and development of secondary hypothyrosis. Administration of Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly tetrapeptides significantly prevented these impairments by increasing the levels of the thyroid-stimulating hormone (TSH) as well as T3 and T4. Restoration of the thyroid functions and morphology was registered to be greater in one-year-old chicken as compared to five-year-old ones.

Effects of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on hormonal activity and structure of the thyroid gland in hypophysectomized young chickens and old hens.

Hypophysectomy in 5-days chickens and old hens was followed by hormonal disturbances and structural changes in the thyroid gland. Administration of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly synthesized on the basis the amino acid composition of extracts from the anterior and posterior lobes of the pituitary gland, respectively, to hypophysectomized birds for 40 days significantly reduced the degree of these changes. The normalizing effect of synthetic peptides on the concentration of thyrotrophic hormone and thyroid hormones in old hens was less pronounced than in chickens.

[Effects of hypophyseal Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly synthetic peptides on immunity, hemostasis, morphology and functions of the thyroid gland in neonatally hypophysectomized chicken and one-year-old birds].

Neonatal hypophysectomy in chicken produces enlarged follicles of the thyroid gland, accumulation of colloids, impressed follicular epithelium, increased nucleus-cytoplasm ratio in thyrocytes, atrophied inter-follicular epithelium, depressed immunity, development of hypercoagulation and depressed fibrinolysis. When hypophysectomy is performed in one-year-old birds the impairments developing in thyroid morphology, immunity and hemostasis are less pronounced. Peptides of the anterior (Lys-Glu-Asp-Gly) and posterior (Ala-Glu-Asp-Gly) thyroid lobes injected to hypophysectomized birds prevent atrophic changes of the thyroid gland, normalize immune and hemostatic parameters.

[Effects of epithalon and cortagene on immunity and hemostasis in neonatally hypophysectomized chicken and old birds].

It has been found that chicken hypophysectomized early in the neonatal period develop anemia, cellular and humoral immune deficiency, hypercoagulation and inhibited fibrinolysis by their 45th postnatal day. An analogous operation performed on old birds produces less significant changes in erythrocytes, immunity and hemostasis. Injections of epithalon tetrapeptide (Ala-Glu-Asp-Gly) administered to either hypophysectomized chicken or old birds during a period of 40 days completely eliminate the shifts registered in erythrocytes, immunity and hemostasis, while injections of cortagene (Ala-Glu-Asp-Pro) which is distinguished from epithalon by a different terminal aminoacid (with Gly being replaced by Pro) do not affect the parameters studied.

[Ontogenetic aspects of morphological and functional characteristics of the thyroid gland in birds].

One can distinguish two most important periods in postnatal ontogenesis of the thyroid gland in birds. On the 5th postnatal day dramatic enhancement of adenohypophyseal endocrine functioning causes thyrocitic activation, which results in elevated levels of the thyroid hormones. The morphological and functional peak of the thyroid gland is within 3-12 months. Old birds manifest reduced production of the thyroid-stimulating hormone and show morphological changes in the parenchyma and stroma of the thyroid gland which eventually result in diminished production of the thyroid hormones.