Summary. The effects were examined of dietary protein concentration and quality on the response of polycythaemic hypertransfused rats to 6 units of human urinary erythropoietin. Rats were either starved or fed one of 14 different diets. Four protein sources were used, having a quality gradient from 100 to about 24. Two proteins—casein and wheat gluten—were used at five different levels of concentration (5–25%) in the diet. The response of rats maintained on the standard diet (Purina rat chow, 23.4% protein/g) was taken as the normal standard. The response to erythropoietin was 25% of normal in starved rats and 35% of normal in rats put on a protein‐free diet. When 10% protein in the diet was obtained by using high biological value proteins (egg yolk or casein) the response to erythropoietin was normal. When the same concentration was achieved by using low biological value proteins (wheat gluten or corn protein) the response to erythropoietin was undistinguishable from that of rats put on the protein‐free diet. When rats were maintained on diets with different concentrations of casein (5–25%) a normal response was observed when protein concentration was 10% with no further changes at higher concentrations. When rats were fed diets with different wheat gluten concentrations (5–25%) the response to erythropoietin was subnormal. These data suggest that the ability of rats to respond normally to erythropoietin is dependent on a continuous dietary intake of proteins at levels which are dependent on their biological values.
Objectives: The aim of the present work was to study the effect of long-term cyclosporine (CSA) administration on norepinephrine (NE) metabolism and adrenergic-evoked secretion in the rat submandibular gland (SMG). Methods: Dose-response curves to adrenergic agonists (methoxamine, isoproterenol, NE) were performed in control and CSA (10 and 30 mg/kg every 2 days for 1 month)-treated rats after SMG duct cannulation. In SMG tissue neuronal NE uptake, release, synthesis and endogenous content were determined. In addition phosphoinositide intracellular signaling was also investigated. Results: CSA administration caused an increase in salivary secretion evoked by methoxamine (α-adrenergic agonist) and NE but failed to modify salivation evoked by β-adrenergic stimulation (isoproterenol). Long-term CSA administration decreased NE release and synthesis whereas it enhanced the amine uptake and phosphoinositide hydrolysis in the SMG. Conclusions: The administration of CSA for 30 days induced salivary gland sensitization likely mediated by diminished adrenergic input. Present results suggest that the decreased sympathetic activity evoked by long-term CSA administration in the rat SMG may lead to sensitization of the gland supported by increased phosphoinositide hydrolysis and enhanced adrenergic-evoked salivation.
Radioiron uptake by erythrocytes, metabolic rate, erythropoietin formation during hypoxia and erythroid responsiveness to exogenous erythropoietin were determined in both starved and water deprived rats. The feed intake showed a marked and progressive reduction during water deprivation. The metabolic rates of rats deprived of either food of water declined progressively showing a 40% reduction 5d after water deprivation or starvation began. At this time, the 24 h red blood cells 59Fe incorporation was 85% lower in both starved and dehydrated rats than in normal rats. Plasma erythropoietin levels in response to hypoxia were approximately 50% decreased in both starved and dehydrated rats. Both polycythaemic starved and polycythaemic water deprived rats injected with human urinary erythropoietin showed a 75% decrease in 59Fe incorporation into erythrocytes when compared to control rats. It is suggested that depression of erythropoiesis during water deprivation in the rat depends on a reduced sensitivity to erythropoietin, possibly associated with decreased production of the hormone. Since water deprived rats drastically reduce feed intake it is suggested that secondary starvation is the principal cause of the decreased erythropoiesis induced in the rat by water deprivation.
Short Communicationsare reported (Herold, Hurvitz and Tadmor 1971). HGH positively influenced the chondrogenesis in 6 patients with delayed union and pseudarthroses (Mühlbach and Hirthe 1967). This investigation has been effected in co-operation with a research team concerned with HGH in the treatment of delayed union and pseudarthroses of bone (Koskinen, Lindholm, Nieminen, Puranen and Attila 1975). For reasons of species specifity optimal response was expected. Material and methoclsTwelve patients with fresh fractures of the lower leg were treated with HGH (Crescormon, Kabi Ab) 16 I.U. i.m. every second day during five weeks in addition to orthopaedic treatment Serum calcium, phosphorus, hydroxyproline, alkaline phospbatase and HGH content plus excretion rates of calcium, phosphorus and hydroxyproline were determined at 0,1,3 and 5 weeks after injury.The progress of healing was interpreted by clinical and radiological evidence. ReSlllts and conclusionsBony union ensued in eleven of twelve patients. The time required for consolidation to take place was 8-12 weeks in 7 patients, 13-16 weeks in 4 patients and more than 16 weeks in one patient.In the control group of eight patients the time required for consolidation was 8-12 weeks in one patient, 13-16 weeks in 6 patients and more than 16 weeks in one patient. In both groups one patient bad to undergo operative treatment for de-Iayed union of the fracture.
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