ISSN:1663-2818    

DOI:10.1159/000178655

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Cholesterol and cholesterol esters were measured on day 90 in the plasma and aortas of rats treated on day 4 as follows: control, gonadectomy, testosterone propionate (TP), estradiol-17β (E). Sex differences were observed in sterol concentrations of control animals but were abolished by castration. TP and E significantly altered sex gland weights, aorta cholesterol and plasma cholesterol esters of both sexes. Little effect on plasma cholesterol or esterified cholesterol of the aorta was noted in any treatment group. A dose effect of E was observed in organ weights and sterols of male rats

ISSN:1663-2818    

DOI:10.1159/000178656

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Insulin is released into the circulation early during fetal life, but the physiological significance of the hormone in the fetus is still unclear. The present study was undertaken to evaluate the possible effects of insulin on the protein metabolism of skeletal and heart muscle during the perinatal period in the rat. When incubating hemidiaphragms in a bicarbonate buffer, 0.1 U/ml ox insulin failed to enhance the incorporation of leucine-4,5–3 H into muscle protein before birth and during the immediate neonatal period. From 3 days of age onwards a stimulatory effect of insulin on protein synthesis was constantly observed. While insulin thus was ineffective in promoting protein synthesis in hemidiaphragms before the third postnatal day, it significantly enhanced the synthesis in heart muscle at an earlier stage of development. Insulin stimulated the uptake of α-aminoisobutyric acid-1-14C into the diaphragm muscle during late fetal life as well as through the early neonatal period. The role of insulin in protein metabolism during fetal life may thus be limited to the augmentation of amino acid transport in skeletal and heart muscle and to a stimulatory effect on protein synthesis only in certain tissue(s), e.g. heart musc

ISSN:1663-2818    

DOI:10.1159/000178657

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The effects of cyclic AMP and cyclic GMP on the incorporation of 3H-uridine into glomerulosal cells of hypophysectomized rats were investigated by high resolution autoradiography. The quantitative analysis of autoradiographs shows that cyclic nucleotides, like ACTH, enhance the tracer incorporation into both nuclear and mitochondrial compartments. These findings are discussed in relation to previous results indicating that both cyclic nucleotides function as intracellular mediators of the trophic action of ACTH on the rat adrenal zona glomerulosa. The hypothesis that the mechanism of the glomerulotrophic action of ACTH and cyclic nucleotides involves the stimulation of nuclear and mitochondrial RNA synthesis is discussed.

ISSN:1663-2818    

DOI:10.1159/000178658

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A well-documented case of partial thyroidal iodide transport deficiency in a patient with E18p- is described. It is suggested that several genes regulating various steps of intrathyroidal iodide utilization are localized in this area of chromosome E18.

ISSN:1663-2818    

DOI:10.1159/000178659

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Electrochemical stimulation of the neocortex, VMH-arcuate hypothalamus, medial preoptic area, corticomedial amygdala, and dorsal hippocampus was performed under pentobarbital anesthesia to determine the brain regions involved in prolactin release as evidenced by pseudopregnancy. Stimulation occurred on the day of vaginal estrus, followed 4 days later by uterine traumatization. All animals were sacrificed 8 days after brain stimulation. Medial preoptic stimulation resulted in an 83 % incidence of pseudopregnancy while VMH-arcuate stimulation resulted in 43 % incidence. Amygdaloid and hippocampal stimulation resulted in a lower incidence of pseudopregnancy (20 and 24 %, respectively). Stimulation of the neocortex or sham stimulation of the five brain regions did not induce pseudopregnancy. These data indicate that the MPOA and VMH-arcuate hypothalamus are areas which may facilitate the release of prolactin necessary for the development of pseudopregnancy. The lower incidence of deciduomata formation resulting from electrochemical stimulation of the amygdala and hippocampus suggest that these areas have a minor effect on stimulating the induction of pseudopregnancy.

ISSN:1663-2818    

DOI:10.1159/000178660

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Pseudopregnancy induced by cervical stimulation was inhibited by acute electrochemical stimulation of the corticomedial amygdala or dorsal hippocampus under sodium pentobarbital anesthesia (40 mg/kg) in adult, cyclic female Sprague-Dawley rats. The degree to which pseudopregnancy was blocked depended on temporal conditions of brain stimulation and sodium pentobarbital administration. Pentobarbital alone had a suppressing effect on the incidence of pseudopregnancy, especially when it preceded cervical stimulation. Limbic stimulation before cervical stimulation had a tendency to potentiate the suppression of pseudopregnancy by pentobarbital. After cervical stimulation, hippocampal stimulation tended to inhibit the development of pseudopregnancy, potentiating the pentobarbital suppression, while amygdala stimulation tended to override the pentobarbital blockage of pseudopregnancy. These findings suggest a negative influence of these two limbic structures and pentobarbital on the secretion of prolactin.

ISSN:1663-2818    

DOI:10.1159/000178661

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The effect of both testosterone-estradiol-binding globulin (TeBG) and albumin on enzymic oxidoreduction of four 17-oxygenated C19 steroids by bacterial 17β-hydroxysteroid:NAD oxidoreductase from Pseudomonas testosteroni was investigated. The decreased yields of products under presence of TeBG were found in both directions of reversible enzymic reaction. This finding was unexpected in the case of enzymic reduction in which the opposite effect could be assumed with respect of high affinity of the product but not the substrate to TeBG. Kinetically, the competition between enzyme and binding protein for the substrate occurs at enzymic oxidation, whereas the mechanism resembling non-competitive inhibition operates in the enzymic reduction

ISSN:1663-2818    

DOI:10.1159/000178662

出版商:S. Karger AG    

年代:1975

数据来源: Karger