1-Alkyl-3-amino-5-aryl-1H-[1,2,4]triazoles: novel synthesis via cyclization of N-acyl-S-methylisothioureas with alkylhydrazines and their potent corticotropin-releasing factor-1 (CRF(1)) receptor antagonist activities.

Cyclizations of alkylhydrazines with N-acyl-S-methylisothioureas, readily synthesized from acyl chlorides, sodium thioisocyanate, dialkylamines then methyl iodide in a one-pot reaction, gave 1-alkyl-3-dialkylamino-5-phenyltriazoles 7 as major products. The regioisomers were assigned through the use of NOE NMR experiments. While bearing a N-bis(cyclopropyl)methyl-N-propylamino group, this series of compounds shows very good binding affinity on the human CRF₁ receptor. Among them, 1-methyl-3-[N-bis(cyclopropyl)methyl-N-propylamino]-5-(2,4-dichlorophenyl)-1H-[1,2,4]triazole 7a had the best binding affinity for the CRF₁ receptor (K_i=9 nM).     

Effects of iron deficiency and exercise on myoglobin in rats

The effects of iron deficiency and endurance training on muscle myoglobin (Mb), body weights, and blood lactic acid concentration were studied in rats. Fifty animals were divided into four groups: anemic trained (AT), normal trained (NT), anemic sedentary (AS), and normal sedentary (NS). Following 5 weeks of dietary control, the mean hemoglobin values for the AT and AS rats were 0.013 +/- 0.002 mmol X l-1 (8.7 +/- 1.4 g X dl-1) and 0.014 +/- 0.003 mmol X l-1 (9.2 +/- 1.7 g X dl-1) respectively, and did not significantly change throughout the study. AT and NT rats were run on a motor driven treadmill 4 days/week for 6 weeks up to a pre-established time of 90 min. Following the training, body weights of the AT (157 +/- 13 g) and NT (153 +/- 13 g) rats were lower than their respective sedentary groups AS (172 +/- 9 g) and NS (176 +/- 15 g). Resting blood lactic acid concentration following training was lower in both trained groups, AT (3.3 +/- 2.0 mM) and NT (2.3 +/- 1.9 mM) compared to AS (8.2 +/- 2.6 mM) and NS (3.8 +/- 1.6 mM). Training increased Mb concentration in hearts of both the anemic and normal trained groups (AT, 0.66 +/- 0.13 mg X g-1; NT, 0.95 +/- 0.08 mg X g-1) compared to the sedentary groups (AS, 0.44 +/- 0.08 mg X g-1; NS, 0.70 +/- 0.13 mg X g-1). Only the AT rats showed an increase in skeletal muscle Mb. This study provides evidence that myoglobin may limit aerobic metabolism.     

Cell Cycle activation and ouabain-sensitive ion movements of 3T3 and C3H-10T½ fibroblasts

The introduction of either PGF_2α (10^?7 M) or TPA (10^?7 M) stimulated, ouabain-sensitive ⁸⁶Rb⁺ influx at 30 min in postconfluent 3T3-4 mouse fibroblast cultures by 117% and 124%, respectively. Both TPA and PGF_2α at these concentrations stimulated the incorporation of ³H-TdR into DNA. TPA had the greatest stimulatory effect, which was similar to that obtained with 10% fetal calf serum. In accord with the idea that modulation of membrane processes such as Na⁺/K⁺ pump activity in fibroblasts may reflect important events related to the initiation of DNA synthesis, it was observed that in both 3T3-4 and C3H-1 0T½ cells there were parallel increases in ³H-TdR incorporation and ouabain-sensitive ⁸⁶Rb⁺ influxes with 10^?7 M TPA, whereas PGF_2α stimulated a significant increase in ³H-TdR incorporation in 3T3-4 but not C3H-10T½ cells and only marginal increases in ouabain-sensitive ⁸⁶Rb⁺ influx in both. Therefore, although there appears to be a close correlation between Na⁺/K⁺ pump activation and subsequent S-phase entry following TPA stimulation, a similar correlation for PGF_2α cannot be confirmed.     

Osteogenesis imperfecta: a heterogeneous morphologic phenotype in cultured dermal fibroblasts

Summary Osteogenesis imperfecta (OI) is a phenotype with clinical and biochemical heterogeneity. We report here that expression of the OI phenotype extends to the level of dermal fibroblast morphology in vitro. Growth characteristics and morphology of control (n=6) and OI cell strains (n=10, representing the four major OI categories, Sillence classification) were compared by measuring the following: (i) days required in culture to reach confluence after plating at uniform density; (ii) cell density at confluence; (iii) width and length of cells (measured on phase contrast micrographs at 300xmagnification). Our results show that: (i) OI fibroblasts take longer (11–27 days, mean 20 days) than control cells (10–19 days, mean 16 days) to reach stationary phase; (ii) all OI phenotypes achieve a lower cell density (0.87x10⁶ cells/P60, range 0.3–1.6x10⁶) at stationary phase relative to control cells (2.2x10⁶ cells/P60, range 1.7–2.6x10⁶; F_4,77=56.1, p<0.01, indicating that OI cells are larger than normal). Cell shape (expressed as the width: length ratio) was also abnormal in OI cells. (F_4,730=37.6, p<0.01), types I and II OI cells have significantly increased ratios (p<0.01) relative to control, type III, and type IV cells. Intra-group phenotypic heterogeneity was also apparent in the OI categories and also within the control population. These findings confirm deviant morphologic phenotypes in OI dermal fibroblasts and further demonstrate interindividual heterogeneity in the expression of genes that determine size and shape of dermal fibroblasts in both OI and normal donors.Publication No. 84013 from the Montreal Children's Hospital Research Institute