Secretion and reabsorption of uterine luminal fluid in rats

Treatment of ovariectomized rats with oestradiol-17beta and progesterone demonstrated that oestradiol-17beta causes secretion of sodium, potassium and water into the lumen of the uterine horn and that progesterone causes reabsorption of these substances.     

The effect of renal vasodilation and hypotonic volume expansion on water excretion in dogs after anesthesia and surgery

The possible effects of renal vasoconstriction from anesthesia and surgery on water excretion after hypotonic volume expansion (HVE) were studied in 18 well conditioned anesthetized dogs, with and without the infusion of phenoxybenzamine and acetylcholine into the renal artery of the cannulated kidney. In 6 dogs (Group 1 - Control) whose renal artery was infused with isosmotic saline, HVE resulted in a bilateral increase in GFR and UV (p < .05). ERPF, Cosm, C_H2O, U_NaV, U_KV, RBF, RVR and MAP did not change significantly. In 6 other dogs (Group 2), whose cannulated kidney was infused with phenoxybenzamine 50 μg/min before and during HVE, GFR increased on the infused side while CH₂O and UV increased bilaterally (p < .05). ERPF, Cosm, U_NaV, U_KV, RBF, RVR and MAP were not affected significantly. The addition of ADH, 2 mu/min into the phenoxybenzamine infusate, decreased ERPF, RBF and RVR bilaterally and CH₂O on the infused side (p < .05). It had no effect upon GFR, Cosm, U_NaV, U_KV and MAP. In another 6 dogs, (Group 3), whose cannulated renal artery was infused with acetylcholine (20 μg/min) before and during HVE, C_H2O, UV and RVR increased bilaterally (p < .05). ERPF and RBF decreased bilaterally (p < .05), whereas GFR, Cosm, U_NaV and MAP were unaffected. U_KV decreased on the infused side (p < .05). The addition of ADH (2 mu/min)_into the acetylcholine infusate, decreased C_H2O bilaterally and increased Cosm and U_KV on the control side (p < .05). It had no effect on ERPF, GFR, UV, U_NaV, RBF, RVR and MAP. These observations suggest that anesthesia and surgery produce renal vasoconstriction and this together with increased ADH release, interfere with water excretion by the kidney. Previous renal vasodilation prevents these influences of anesthesia and surgery.     

Isopropanol enhancement of carbon tetrachloride metabolism in vivo

We examined the effects of isopropanol (ISOP) pretreatment on the metabolism of ¹⁴CCl₄ to ¹⁴CO₂ and CHCl₃ exhaled in the breath, to ¹⁴C metabolite excreted in 24 hr urine and feces from 0 to 24 hr, and to ¹⁴C metabolite bound to liver at 24 hr. Fasted male rats were given 0.1 or 2.0 mmoles ¹⁴CCl₄/kg. ISOP pretreatment, which markedly enhanced the hepatotoxicity of CCl₄, selectively enhanced the rate and total extent of ¹⁴CO₂ and CHCl₃ metabolite exhalation. The pathways of CCl₄ metabolism leading to CO₂ and CHCl₃ metabolite formation may be more relevant to the hepatotoxicity of CCl₄ than the pathways leading to urinarym fecal or covalently bound metabolites.     

Lack of effect of toxic aluminium concentrations on nitrogen fixation by nodulatedStylosanthes species

Summary Effects of three solution aluminium concentrations (0, 25, and 100M) on nitrogen fixation by well-nodulated plants ofStylosanthes hamata, Stylosanthes humilis andStylosanthes scabra are reported. Plants were inoculated with Rhizobium CB756 and grown for 21 days in an aluminium-free nutrient solution at pH 5.3 before imposition of the aluminium treatments.Nitrogen fixation was measured both by the increase in total nitrogen content of the plants and acetylene reduction in roots of plants harvested at 10 and 20 days after imposition of the aluminium treatments. Solution aluminium concentrations as high as 100M, had no detrimental effect on nitrogen fixation in any species.     

Abscisic acid and gibberellin-like substances in roots and root nodules ofGlycine max

Summary The content of endogenous gibberellin (GA)-like substances of roots and root nodules of SOya, and GA production byRhizobium japonicum cultures, were investigated by a combined thin layer chromatographic (TLC)-dwarf pea epicotyl bioassay technique. GAs were more concentrated in root nodules than in the roots, totalling 1.34 and 0.16 nM GA₃ equivalents g⁻¹ dry wt. respectively. GA production byR. japonicum cultures was demonstrated (1.00 nM GA₃ equivalentsl ⁻¹) and comparison of the GA components of plant and bacterial culture medium extracts, suggested that rhizobial GA production may contribute to the nodule GA content. Cis-trans abscisic acid (ABA) was identified in root and nodule extracts by TLC-gas liquid chromatography (GLC), and amounted to 0.18 and 2.21 nM g⁻¹ dry wt. respectively, whereas 0.30 and 4.63 nM ABA equivalents g⁻¹ dry wt. were detected by a TLC-wheat embryo bioassay technique. ABA was not detected in extracts of bacterial cultures.     

Abnormally spliced messenger RNA in erythroid cells from patients with β+ thalassemia and monkey cells expressing a cloned β+-thalassemic gene

The reduced β-globin synthesis characterizing the β⁺ thalassemia phenotype has been shown to be caused by anomalous processing within the small Intervening sequence (IVS1) of the β-globin mRNA precursor. The β-globin gene from such patients contains a single base substitution within IVS1, located 22 bp from the 3′ junction between IVS1 and exon 2, creating an alternative splice site within IVS1 and resulting in retention of the 3′-terminal 19 bases of IVS1. We have identified this abnormally spliced mRNA in the reticulocyte RNA of two patients with β⁺ thalassemia, by S1 nuclease mapping and primer-extension analysis. Moreover, a cloned β⁺-thalassemic gene preferentially generated the anomalously spliced RNA when expressed In monkey kidney cells. The anomalously spliced RNA constituted approximately 80%–90%, and normal β RNA approximately 10%–20%, of the total β mRNA. In contrast, the small amount of β mRNA present in reticulocytes from such patients consisted predominantly of normal β mRNA. These results suggest that the reduced amount of normally functioning β mRNA present in such patients results from preferential processing at the alternative splice site, with subsequent Instability, reduced nuclear processing and/or inadequate cytoplasmic transport of the abnormal RNA species.     

The effects of organic nitrogen sources on growth of cell cultures of Douglas-fir

In order to establish rapidly growing, friable cell cultures of Douglas-fir ( Pseudotsuga menziesii [Mirb. (Franco)], the effects of organic sources of nitrogen on growth were investigated. Of the nitrogen sources studied, including allantoin, allantoic acid, glutamine and glutamic acid, all were capable of increasing growth. Glutamine (50 m M ) produced the most marked increase in growth boosting dry weight production to a level of four times that of controls. Glutamine additions also eliminated the lag phase of growth and caused cells to become densely cytoplasmic. Results are discussed in relation to the pathway for assimilation of nitrogen.     

Separation of mannosylretinylphosphate from dolichylmannosylphosphate by chromatography on columns of DEAE-sephacel

A one-step column chromatographic procedure on DEAE-Sephacel allows the separation of mannosylretinylphosphate from dolichylmannosylphosphate with minimal breakdown of the mannosylretinylphosphate. Using this procedure, subcellular fractions of rat liver were shown to be active in synthesizing both mannolipids from GDP-[¹⁴C]mannose in the absence or presence of exogenous retinylphosphate.     

Immunohistochemical evidence for a plasma membrane localization of dopamine-beta-hydroxylase in the mouse neuroblastoma

Dopamine-beta-hydroxylase (D beta H), a glycoprotein enzyme which converts dopamine into noradrenaline, was purified from C1300 mouse neuroblastoma and used to raise antibodies in rabbits. Using an indirect immunofluorescence technique the cellular localization of D beta H in C1300 mouse neuroblastoma was compared with that of the superior cervical ganglion. C1300 neuroblastoma D beta H was found to be predominantly localized in the plasma membrane, in contrast to its intracellular localization in the superior cervical ganglion of A/J mice. At least part of the enzyme was found to be associated with the external side of the plasma membrane.     

Serological detection of H-2K- and H-2D-gene products

Using the fluorescence-activated cell sorter (FACS II), we have analyzed the expression of H-2K- and H-2D-gene products on the membrane of various cellular components of the murine immune system. Using this serological technique we show a basic difference between T and B lymphocytes. Whereas all cellular components analyzed — hydrocortisone-resistant thymocytes, splenic T and B lymphocytes, macrophages and bone-marrow cells — expressed H-2K-subregion-encoded alloantigens at a high density, it seems that the high density expression of H-2D-encoded alloantigens is restricted mainly to B cells and to macrophages. Hydrocortisone-resistant thymocytes, splenic T lymphocytes and bone-marrow cells, on the other hand, showed significant expression of the H-2D alloantigens only at low membrane density. These results, then, provide evidence for the existence of an imbalance in serologically detectable expression of H-2K- and H-2D-region-gene products on the cell membrane of various cells comprising the murine immune system.Abbreviations usedin this paper DTH delayed type hypersensitivity - FCS fetal calf serum - FITC fluorescein isothiocyanate - HrT hydrocortisone-resistant thymocytes - Ig immunoglobulins P. De Baetselier is an EMBO and Euratom postdoctoral fellow