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Virgin female Microtus ochrogaster were exposed to paired and unpaired unfamiliar adult males in semi-natural arenas. Although females were reproductively activated by both types of males, more than twice as many were activated by unpaired (51.6%) as by paired (18.2%) males. Our results suggest that, in natural populations of prairie voles, the proportion of philopatric females becoming reproductive is related to the abundance of unpaired males within the population.

1. 1. The acidic and neutral glycoproteins secreted by cultured tracheal explants from pigs, sheep, rats, mice, monkeys, guinea pigs, dogs and chickens were purified and fractionated by column chromatography on DEAE-cellulose and by electrophoresis on cellulose acetate. 2. 2. The ratios of acidic to neutral mucus glycoproteins were compared for the above animais with that of mucus glycoproteins secreted by cultured human bronchi. 3. 3. The observed ratios of acidic to neutral glycoproteins ranged from 4.0 (mouse) to 7.2 (chicken and pig) from cultured tracheae; secreted human bronchial mucus had a ratio of 2.7. 4. 4. The ratio of acidic to neutral glycoproteins secreted by tracheal explants varied with duration of incubation of the trachea in culture.

The concentrations of glycolate (hydroxyacetate) and lactate are significantly elevated above control values in urines from streptozotocin-diabetic rats, regardless of whether data are expressed in terms of μg/ml urine or μg/day. The same levels of oxalate and glyoxylate are excreted in 24 h in the urines from normal and diabetic rats. Lactate levels are elevated above control values in serum from streptozotocin-diabetic rats. The elevation of glycolate levels in diabetic rat urine compared to control values occurs regardless of diet and regardless of whether rats were fed or fasted during the 24 h urine collection period. Rat liver glycolate oxidase may be used to assay glycolate concentrations in the presence of up to 500 μg/ml l -lactate when pH 8.6 Tris-Cl is used as buffer. Results obtained with this assay compare qualitatively with the standard colorimetric assay using 2,7-dihydroxynaphthlene for glycolate determination. Beef liver glycolate oxidase is not effective for use in glycolate assays. The identity of urinary glycolate was confirmed by gas-liquid and by paper chromatography.

1. 1. The sorbitol dehydrogenases [ l -iditol: NAD oxidoreductase] from livers of cow, man, rat and sheep each possess molecular weights of about 140,000. The beef, rat and sheep liver enzymes are composed of subunits of molecular weight 40,000. 2. 2. The sorbitol dehydrogenases from livers of these four species each possess an isoelectric point of 7.3. 3. 3. The four enzyme preparations show identical mobilities upon disc-gel electrophoresis and yield a single band of enzymic activity. 4. 4. Sorbitol dehydrogenase activity is activitated by the presence of ampholines or by increasing ionic strengths, with maximal activation at about 0.5 M salt concentration. These factors may cause the Km for NAD to be lowered.

SummaryThe 24-hr urine collected from streptozotocin-diabetic rats contained activities of acid phosphatase, alkaline phosphatase, N-acetyl-β-D-glucosaminidase, α-L-fu-cosidase, β-D-galactosidase, glutamate-oxal-oacetate transaminase, and α-D-mannosi-dase that were significantly greater than control values. Lactate dehydrogenase activity was similar in urines from diabetic and from control animals. Results were similar with rats injected with streptozotocin from 3 to 30 days prior to use. The levels of urinary acid hydrolase activities present in diabetic rats returned to control values upon treatment with insulin and became elevated above control values once again upon cessation of insulin treatment. The levels of enzymatic activity measured in diabetic rat urine, except for LDH, were directly proportional to the volume of urine produced. However, normal animals with induced polyuria did not produce urines with enzymatic activities above control values.This study was supported by USPHS Grant 5685-12, the...