F A Opmeer

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We have studied the possible influence of steroid hormones and a beta-agonist (clembuterol) on hepatic insulin-like growth factor 1 (IGF1) production in young calves. For this purpose nine 20- to 40-day-old Holstein X Friesian male calves were fitted with chronically indwelling catheters in hepatic and portal veins and hepatic artery. Estradiol induced a(More)
In a 5-year-old boy presenting with clumsiness and excessive growth, a large craniopharyngioma was diagnosed. Biochemically, there was a deficiency of growth hormone, a hypothalamic hypothyroidism and hypocorticalism, a thyroxine binding globulin elevation, an abnormal gonadotropin secretion and a mild hyperprolactinaemia. After removal of the tumour growth(More)
Cyclic GMP levels were dose-dependently increased by excitatory drugs such as picrotoxin, pentetrazol, oxotremorine and harmaline in mouse cerebellum and medial forebrain (parts of the cortex, hippocampus, hypothalamus, thalamus, striatum and midbrain) in vivo. Cyclic AMP levels remained unchanged under these conditions. Pretreatment with diazepam(More)
The present study was aimed at determining the influence of nutrients supplied by a milk diet (glucose, amino acids, triglycerides) on hepatic somatomedin C (IGFi) production in vivo in four 30-d-old milk-fed calves fitted with chronically indwelling catheters in hepatic (HV), portal (PV) and mesenteric veins and in the hepatic artery (HA), and with(More)
Plasma GH and IGF1 concentrations were measured during the last 2 months of gestation in 9 chronically catheterized fetal calves under basal conditions or following growth-hormone-releasing factor (GRF), thyrotropin-releasing hormone (TRH) or SRIF intravenous cotyledonnary injections. Plasma GH concentrations were higher in fetuses (1.40 +/- 0.10 nmol/l)(More)
Groups of rats were pretreated with 4-week diets containing 12.5% corn oil or linseed oil. At the end of this period peritoneal macrophages were elicited and isolated. These cells were used for binding experiments with 3H-PGE2 and for estimation of prostaglandin-stimulated cAMP production. Specific binding of 3H-PGE2 was saturable, reversible,(More)
A method is presented which provides for a simple and rapid determination of PGE2 receptors on viable peritoneal macrophages. Incubation of the harvested cells with (3H)PGE2 revealed specific binding of (3H)PGE2 by use of the Millipore filter assay system. Maximum binding was attained in the presence of 1 mM EDTA. Specific binding was saturable at 65(More)