ПОШИРЕННЯ, ЕТІОЛОГІЯ ТА ДІАГНОСТИКА ГІПОТИРЕОЗУ У КОРІВ ЖИТОМИРСЬКОГО ПОЛІССЯ

Zhytomyr Polissya of Ukraine is part of the biogeochemical zones, which is characterized by insufficient content of biotic trace elements, including iodine, lack of which in the environment is a common biological and medical problem. Animals, which being in a single food chain with a man, have geochemical and environmental impacts in a greater degree. The main reason for the decrease in the functional activity of the thyroid gland in cows is low iodine content in soils and, as a consequence, in animal feed and their contamination with radionuclides – 137Cs and 90Sr. Low total contents in the soil of the territory of the synergists of iodine – cobalt – 1.7 – 2.5 mg/kg (optimal 7 – 30), copper –1.1 – 2.7 (15 – 60), zinc – 13.2 – 31.0 mg/kg (30 – 70), and in some places, and manganese contribute to the development of this disease.The symptoms of iodine deficiency, which is typical for hypothyroidism: dryness and hyperkeratosis of the skin, the long hair site the withers, anemone conjunctiva, enophthalm, bradycardia, myxedema, thyroid enlargement were installed by clinical studies. So, 90% of the cows revealed hypofunction of the thyroid gland : content thyroxine the blood serum was in the range 28.3 to 54.7 nmol/l and averaged a 43.8 ± 2.7 nmol/l (3.4 ± 0.21 mg/100 ml).Micronutrient deficiency causes a disruption of haematopoiesis and the development of anemia in 85% of cows that expressed agociting (75 – 80%) and olgahoney (of 41.7 – 66.7 percent). Anemia, mainly macrocytic and hyperchromic, rarely normochromic.Erythrogramma of cows notes longer left part, compared with animals a safe zone, that indicates on a significant number of «old» age of red blood cells, and stretched the right part that is due to the increased number of more resistant to hemolysis immature «young»erythrocytes.

The Role of Secreting Structures Position on the Leaf Volatile Organic Compounds of Hypericum androsaemum

Hypericum androsaemum L. presents typical translucent, essential oil producing glands, which are distributed on the leaf along both margins (margin glands) and on the lamina (lamina glands). The gland secretion was studied by histochemical and chemical analysis; the gland content was sampled directly from the secretory glands, and the volatile organic compounds (VOC) of the margin and lamina glands were separately analyzed. The lipophilic fraction of the lamina glands had as main components: (E)-2-hexenal (15.5%), hexadecanoic acid (14.7%), β-caryophyllene (11.2%), germacrene B (11.0%) and γ-himachalene (9.8%). The lipophilic fraction of the margin glands had as its main components: β-pinene (22.0%), limonene (17.6%), (E)-β-ocimene (6.1%), methyl linoleate (5.7%), terpinolene (5.4 %), (E)-2-hexenal (4.9%) and α-pinene (4.1%).

Effects of chronic thyroid hormone administration on pregnancy, lactogenesis and lactation in the rat

We studied the effects of daily administration of 1 mg/kg thyroxine (T4) starting 10–15 days before mating, on parturition, maternal behavior and lactation in rats. Treated rats had elevated serum titers of T3 and T4, a greater number of fetuses and parturition was advanced approximately 12 h and lasted longer than in controls. None of the treated rats were able to lactate because of defects in maternal behavior and milk ejection; the litters died usually within 48 h postpartum. In rats sacrificed at 10.00 on day 21 of pregnancy, mammary gland content of total protein, phospholipids, casein and lactose were significantly increased, but total lipid was markedly reduced. Lipogenesis was also significantly increased, as well as the activity of the lipogenic enzymes glucose-6-phosphate dehydrogenase, fatty acid synthetase and isocytrate dehydrogenase. These results are indicative of normal albeit premature lactogenesis. The T4-treated rats also had advances in the prepartum fall in serum progesterone and the increase in prolactin as well as in the increase in mammary casein and lactose concentrations of approximately 12 h with respect to control pregnant rats. These results show that chronic T4 treatment induces an advance of approximately 12 h in luteolysis, which in turn advances lactogenesis and parturition in rats. Although the mammary gland was able to produce milk, lactation failed due to abnormal maternal behavior and milk ejection, the causes of which are still unknown. Other effects of hyperthyroidism were also present, such as a severe reduction in lipid content of the gland. The observed increases in lipogenesis and lipogenic enzyme activities could be due to a combination of the effects of hyperthyroidism per se as well as to the increase in lipogenesis that occurs during lactogenesis.

Dopamine may be a neurohormone in rat adrenal cortex

In the periphery, dopamine (DA) is a precursor for norepinephrine (NE) and epinephrine (EPI) biosynthesis and is itself a neurotransmitter in sympathetic ganglia. In addition, DA may function as a neurohormone in providing maximum tonic inhibition of aldosterone secretion from the adrenal cortex. We have quantified the catecholamine content of the adrenal gland and have examined factors that regulate DA content of the adrenal cortex. Adult male Sprague-Dawley rats were assigned to one of four groups: adrenal demedullated (ADM); adrenal denervated via splanchnic nerve section (ADN); adrenal demedullated-denervated (DMN); and sham-operated controls (Sham). Ten days after surgery, rats were killed by decapitation, and the adrenals were removed and later assayed for catecholamine content. Compared with Sham, ADM and DMN decreased NE and EPI levels by 92–99% but DA levels by only 57–58%. ADN decreased levels of each catecholamine by 18–26%. These findings indicate that the adrenal cortex contains approximately 40% of the total gland content of DA and less than 8% of the total gland content of NE and EPI. Furthermore, DA in the adrenal cortex does not appear to require an intact splanchnic nerve supply to the adrenal. In a second experiment, we examined the effects of inhibition of catecholamine biosynthesis with alpha-methyl-p-tyrosine (alpha-MPT) on DA content in Sham and ADM rats. In Sham rats, alpha-MPT decreased adrenal DA by 44% and heart NE by 37%. In contrast, treatment of ADM rats with alpha-MPT increased adrenal DA by 49% but decreased heart NE by 36%.(ABSTRACT TRUNCATED AT 250 WORDS)

INTERACTION BETWEEN OESTROGEN AND GONADOTROPHIN-RELEASING HORMONE ON THE RELEASE AND SYNTHESIS OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE FROM INCUBATED PITUITARIES

SUMMARY The release and synthesis of LH and FSH were studied in adenohypophyses from ovariectomized rats incubated for a period of 4 h in flasks containing 1 ml Eagle's medium. One hemipituitary was used as the experimental gland and the other half served as a control. Glands from ovariectomized untreated animals showed a spontaneous release of LH and FSH and the amount of hormones released (per mg gland) by both the hemipituitaries was not significantly different. Also the content of the hormones at the end of the incubation period was similar in both halves. Gonadotrophin-releasing hormone (Gn-RH) added to the incubation medium stimulated the release of LH and FSH. A dose–response relationship was obtained between doses of 0·51 and 8·00 ng/ml medium. Although lower doses were required to increase the release of LH, the amount of FSH released was higher when expressed as a percentage of gland content. Pituitary glands from ovariectomized rats treated with 5 μg oestradiol benzoate 24 h before being killed showed an increase in sensitivity to Gn-RH, but the response decreased when oestrogen was injected 2 h before death. Also the addition of oestradiol-17β to the incubation medium inhibited LH and FSH release induced by Gn-RH. Gonadotrophin-releasing hormone increased the spontaneous synthesis of LH and FSH observed in the incubated pituitaries. This effect of Gn-RH was stimulated by the injection of oestrogen into the donor animals whereas administration of oestrogen into the medium enhanced the synthesis of LH and partially inhibited that of FSH. These results provide evidence for a dual effect of oestrogen on the release of LH and FSH induced by Gn-RH. They also show that synthesis of gonadotrophic hormones was favoured by oestrogen or by increased gonadotrophin release.

Influence of the Adrenal Glands on the Sialic Acid Content of Submaxillary and Retrolingual Glands in the Rat

Adrenalectomy decreased sialic acid content in the submaxillary and retrolingual glands of normal male rats. The administration of cortisol acetate to adrenalectomized rats increased submaxillary and retrolingual sialic acid content; administration of desoxycorticosterone acetate decreased the submaxillary gland content but not the retrolingual gland content.