Endokrinologie最新文献

Effects of three consecutive days injections of thyroxine (T4) of different doses (1, 2 and 4 micrograms/g of body weight) on different parts of the brain of Singi fish were studied. T4 enhanced the cranio-somatic index and the weight of different substructures of brain, viz., cerebrum, cerebellum midbrain and medulla oblongata, of Singi fish at 25 degrees C. Compared to the control, the protein content of cerebrum increased with all doses of T4 (1, 2 and 4 micrograms/g) and the RNA content of this region increased only with higher doses (2 and 4 micrograms/g). Cerebellum appeared to be relatively less responsive than cerebrum; T4 at the dose of 4 micrograms/g was only effective in increasing the protein content of the cerebellum, although the RNA content of this region was enhanced with both 2 and 4 micrograms of T4 per g. In midbrain and medulla oblongata, the protein content was elevated only with higher doses (2 and 4 micrograms/g) and RNA content was enhanced with all doses of T4 used. T4 injections did not cause any alteration of the DNA content of cerebrum and cerebellum, but in midbrain this cellular constituent increased in amount with all doses of T4 and in medulla oblongata it was increased with the dose of 2 or 4 micrograms of T4 per g body weight.

The postovulatory effects of pharmacological doses of LH-RH on progesterone and LH plasma concentrations have been demonstrated. LH-RH injected on the 16th and 18th day of the menstrual cycle induces the discharge of LH; the second application results in a weaker discharge, indicating that the pituitary stores are exhausted. A LH-RH injection induces a decrease of the plasma progesterone concentration which becomes evident after a delay of 26 hours. A statistically significant correlation between LH and progesterone plasma concentrations was obtained 26 h after the administration of LH-RH.

STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4,9(10)-diene-3-one) or levonorgestrel was given orally as a single dose of 0.4 mg per animal. Treatment was performed immediately after the 6 h mating period. In 30 control cycles (18 animals) 9 pregnancies (30%) and in 26 cycles (17 animals) with levonorgestrel treatment 3 pregnancies (11.5%) were observed. In 46 cycles (21 animals) with STS 557 treatment only one pregnancy (2.2%) occurred (chi 2-test: P less than 0.01 as compared to control cycles). Therefore, STS 557 showed high interceptive activities in this nonhuman primate model. In contrast with levonorgestrel, STS 557 did not decrease the postovulatory rise of plasma progesterone.

Experiments were carried out in the rabbit, with view to elucidating the role of limbic-hypothalamic system in the adrenocortical responses to repeated cold exposures. In each sham-lesioned group, in the rabbit with lesioned in bilateral stria terminalis and dorsal fornix, the formation of adrenocorticoids in adrenal was markedly increased by 1st cold exposure (cold exposure on 1st day), with the adrenocortical responses to 1st cold exposure being nearly the same in these groups. The bilateral lesions in periventricular arcuate nucleus and ventromedial hypothalamus decreased the adrenocortical responses to 1st cold exposure. In each sham-lesioned group, and in the rabbits with lesioned in bilateral periventricular arcuate nucleus, ventromedial hypothalamus and dorsal fornix, there were no effects of 7th cold exposure (cold exposure on 7th day) on the formation of adrenocorticoids. However, in the rabbits with lesioned in bilateral stria terminalis, the formation of adrenocorticoids was markedly increased by the 7th cold exposure. From these results it might be suggested that periventricular arcuate nucleus and ventromedial hypothalamus participated to adrenocortical response to 1st cold exposure, and the amygdala-stria terminalis system played some role in the establishment of adaptation to repeated cold exposures in adrenocortical responses.

The present paper deals with the activity of the sympatho-adrenal system (SAS) in the third international crew of the scientific orbital station "Salyut-6" on the basis of catecholamines (CA) as well as of some of their primary stages and metabolites. Plasma adrenaline (A), noradrenaline (NA), and dopamine (DA) were determined on the 30th day before the flight and on the first day after landing. The parameters of A, NA, DA, DOPA, metanephrine (MN), and normetanephrine (NMN) as well as their conjugates were analysed in urine on day 30 and from days 5 to 1 before launching the spaceship and from days 0 to 5 after landing. Moreover, at the same occasions the urinary excretion of vanillilmandelic acid (VMA) and homovanillic acid (HVA) was measured. For a qualitative evaluation of the responses of SAS indices were computed providing information on the activity of the single links of CA metabolism. During the last five days before launching a gradual increase of A, NA, DA, and DOPA excretion with the urine was found in both the cosmonauts. The A/NA quotient rose to 360% in the commander and to 200% in the spacecraft engineer. The inactivation processes of A (MN/A) and NA (NMN/NA) were clearly reduced in both crew members before launching. The highest excretion of A, NA, DA and their conjugates as well as of DOPA was observed on the day of landing. The total results ascertained in the post-flight period indicate psychonerval strains experienced by the cosmonauts. However, marked stress reactions were not found. This conclusion is drawn on the basis of general criteria of the indices of CA metabolism during stress (increased secretory activity of SAS and excretion of free CA, synthesis activation, relative hypometabolism of conjugation). The rapid normalisation of the investigated parameters after the flight gave evidence of the cosmonauts' quick readaptation, which again is an expression of a high state of preparatory training.

A report is given on experience gained during the electroneurographic examination of 800 diabetics of all ages and on the results of respiratory heart arrhythmia measurement on 215 diabetics. It is proposed that diabetic nervous disturbances should be divided into the following groups: 1--early diabetic and subclinical disturbances, 2--somatovisceral polyneuropathy in type I diabetics, 3--polyneuropathy in type II diabetics, 4--mononeuropathy, mononeuropathy multiplex and proximal amyotrophy. The disturbances in group 1 can be reversed by metabolic control. Only the PNP in group 2 shows a firm statistical correlation to duration of diabetes mellitus and to microangiopathy. This appears to be a dying back neuropathy, probably caused by the chronically catabolic metabolic situation.

The fish Tilapia mossambica were exposed for 30 days to continuously illuminated black or white backgrounds. When compared with the controls the black-adapted fish showed multiplication of the melanophores with a maximal dispersion of the melanosomes. The white background induced blanching of the fish because of depletion of the melanophores and aggregation of the melanosomes. The treatment evoked major changes in the pars intermedia cells. Of these, the amphiphils were stimulated in the black-adapted and regressed in the white-adapted fish indicating that these cells secrete melanophore stimulating hormone. The cyanophils showed depressed activity in the black-adapted fish, but in the white-adapted animals they were stimulated. These alterations suggest the elaboration of a melanophore concentrating hormone by the cyanophils. Regressive effects were also recorded in the gonadotrops and gonads of the experimental T. mossambica.