Effect of prolactin on the enzymatic activity of thyroid follicular cells during stress due to surgery and subsequent subcutaneous inflammation

In order to reveal prolactin (Prl) effect on the enzymatic activity of the thyroid follicular cells at a subcutaneous inflammation, 2 series of experiments have been performed on 100 non-inbred male rats with body mass of 150-170 g. In order to produce the inflammation, under ether narcosis celloidin globules are introduced subcutaneously in the abdominal wall. The test animals are given 0.125 mg of "Lactin" (the Soviet preparation of bovine Prl) in 0.5 ml of isotonic solution once every day, beginning immediately after the operation. At the same time the control animals are given 0.5 ml of isotonic solution. The time of observations are--2, 12 h, 1, 2, 3, 5, 10, 15 days after the operation. As a result of quantitative cytochemical investigation of the enzymatic activity in the thyroid follicular cell, multiphasic dynamics of SDG, LDG, G-6-PhDG, NADH-DG, NADPhH-DG, MAO activity and changes in carbohydrate metabolism type at various time of the subcutaneous inflammation are revealed. Daily injections of Prl against the background of the inflammation reduce amplitude of fluctuations of the enzymatic activity in thyrocytes. At late stages of inflammation (up to 2 days) Prl slows down the decrease of SDG, G-6-PhDG, NADH-DG, NADPhH-DG activity and accelerates decrease of LDH activity. At early stages of inflammation (3-15) Prl slows down decrease of NADPhH-DG, NADH-DG activity and decreases LDH and NADH-DG activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of cortisol administration on development of the thyroid and adrenal axes in rats

Intraperitoneal (IP) injections of cortisol were administered to neonatal male rats on postnatal days 1 to 4. Plasma triiodothyronine (T₃), thyroxine (T₄) and corticosteroids were determined on days 5, 10, 13, 16, 20, 30 and 60 of age, and all animals were weighed weekly. Neonatal cortisol treatment resulted in depressed body weight gain and transient depression in plasma T₄. These results indicate that while body weight is significantly affected by cortisol treatment ontogenic patterns of plasma T₃, T₄ and corticosteroids develop normally.     

Histochemistry of connective tissue cells in subcutaneous adipose tissue of normal and decapitated pig fetuses

Connective tissue cells that are histochemically and morphologically distinct from 'fibroblasts' are localized around developing hair follicles in the pig and rat. Immature adipose tissue is limited to small areas immediately around fully descended hair follicles in the rat hypodermis. In the present study, connective tissue around large nerves and blood vessels in fetal pig subcutaneous tissue was examined for the presence of enzymes typical of adipocytes. Samples from decapitated pig fetuses were studied so that the effects of an altered hormonal profile could be examined. Samples of dorsal subcutaneous adipose tissue were obtained from fetuses at 65, 70, 85, 90, 110, and 112 days of gestation. Fetuses were decapitated in utero at 45 days of gestation, and adipose tissue samples were obtained from these fetuses at 110 days of gestation. A close spatial relationship was observed between the growth of large blood vessels and nerves and fat cell cluster development in the older (greater than 70 days) fetuses. Connective tissue cells that were contiguous with fat cell clusters were histochemically identical to adipocytes. The lipid histochemistry of the reactive connective tissue cells (histochemically identical to adipocytes) was variable in young fetuses. In all 110-and 112-day-old fetuses, the reactive cells contained lipid, whereas the reactive cells in decapitated fetuses were devoid of lipid. The reactive connective tissue cells were not associated with capillaries and did not contain basement membranes. The histochemistry of these cells suggests that they respond to a particular hormonal or metabolic profile as do adipocytes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of substance P on behavior in the rabbit and the activity of cortical neurons during training

Subcutaneous injection of substance P to rabbits in a dose of 250 mcg/kg elicited a transitory disappearance of motor reactions to painful reinforcing stimuli and a reduction of their probability to reinforced and inhibitory light flashes, as well as a protracted heart rate increase and decrease of respiration rate. One third of the neurones recorded decreased their background firing level and or excitatory components of the reactions to reinforcement and conditioned light flashes. The decrease was most distinctly seen in the sensorimotor cortex and less pronounced in the visual cortical area and hippocampus. The influence of the substance P on different types of cortical inhibition was not the same. Tonic inhibition of neuronal activity in response to reinforcement was enhanced. Bioelectrical parameters which reflect an enhancement of inhibitory hyperpolarization during elaboration of internal inhibition (i.e. inhibitory firing delays and corresponding background and evoked slow potentials oscillations) were not changed.     

Porcine adrenal prolactin receptors: characterization, changes during neonatal development and effects of hypoprolactinemia

1. Adrenal prolactin (PRL) receptors were identified within the adrenal cortex of pigs (Sus domesticus), and found to be located specifically on isolated zona fasciculata/reticularis cells (6437 sites per cell). 2. These PRL receptors were associated with binding to [125I]-oPRL which was characterized as being time and temperature dependent, specific for PRL, saturable, of high affinity (Ka = 10(10)/M) with a single class of binding sites, and irreversible except under extreme conditions. 3. The concentrations (fmol/mg protein) of PRL receptors decreased by 35% (P less than 0.05) between 3 and 10 days of age, and subsequently remained constant until 30 days of age. Total content (fmol/paired adrenals) increased progressively (2-fold, P less than 0.05) between 3 and 30 days of age. 4. Short-term (less than 16 hr) and prolonged (7 weeks) hypoprolactinemia (46-64% of control levels, P less than 0.05) were not associated with changes in numbers of porcine adrenal unoccupied PRL receptors.     

Changes of redox activity during the development of rape

Redox activity was measured in vegetative and generative apical parts (5 mm of the stem) and youngest leaves of winter (cv. "G6rczański") and spring (cv. "M?ochowski") rape. Both genotypes were cultured under the same growth conditions (17/15 degrees C day/night, 16 h photo-period), but winter rape was additionally vernalized (5/2 degrees C day/night, 56 days) in order to induce the generative development. The cyclic voltammetric method was used to measure the redox potential of samples in the presence of Fe3+ ions. Changes in the redox activity were compared with changes in riboflavin content and activities of antioxidative enzymes: superoxide dismutase (SOD) and catalase (CAT). The higher level of Fe3+ ions and riboflavin detected in generative apices and leaves of winter and spring varieties indicated that electrons (and their donors) were present at a lower level in these organs in comparison with the vegetative ones. On the contrary, SOD and CAT activity were lower in generative than in vegetative organs. This confirms changes in the redox balance and involvement of oxygen radicals in the generative development of rape plants. The similarity of the measured parameters between winter and spring varieties indicates that the observed changes are independent of the way of generative induction (vernalization). Riboflavin can serve as one of the electron carriers between other oxidation-reduction substances.     

Changes in hepatocytes and the functional activity of the adrenal cortex in rats following administration of the pigment anthraquinone violet

The response of hepatocytes and cells of adrenal cortex of males of white rats to a single introduction per os of sunflower oil or anthraquinone violet pigment (AVP), routinely used for the painting of plastics, was evaluated. 5 ml of sunflower oil or of AVP, prepared as oil suspension, were fed. After 1 or 24 hour introductions of oil, an increase in dividing ability of hepatocytes was observed, whereas after 6 or 72 hour introductions no difference from the control was registered. The introduction of oil caused a decrease of the functional activity of cells in fasciculata zone of adrenal cortex after 1, 6, 24 and 72 hours, as judged from changes in the nuclear volume. AVP in doses of 5.0 and 1.2 g/kg intensified hepatic polyploidy after 1 and 24 hours as compared with rats administered only the oil. After 6 and 72 hours, no difference from the control was registered. In the fasciculata zone of adrenal cortex, AVP in both the doses employed increased the functional activity of cells after 1, 6 and 24 hours. The nature of the response of hepatic cells on the introduction of the above substances presumably depends on the degree of adrenal cortex functional activity.