Comparative biochemistry and physiology. A, Comparative physiology最新文献

1. Sugar best single chorda tympani nerve fiber of rat and hamster were tested with six sugars. 2. Fibers were selected for this experiment, only if they responded to 1.0 M sucrose or 1.0 M maltose and they responded poorly to 0.1 M NaCl. 3. In rat, some single fibers gave larger responses to maltose than to sucrose, while in hamster nearly all nerve fibers responded best to sucrose. 4. The order of effectiveness of sugars was maltose greater than fructose greater than or equal to lactose greater than sucrose greater than glucose greater than galactose in rat and sucrose greater than fructose greater than or equal to glucose greater than or equal to galactose greater than maltose greater than lactose in hamster.

1. The receptor potential of the mouse taste cell was recorded with an intracellular microelectrode while taste stimuli were applied to the tongue surface of the anesthetized mouse. 2. A membrane depolarization accompanied by an increase in membrane resistance was observed after a sucrose stimulus. 3. A sodium-chloride stimulus initiated a membrane depolarization accompanied by a decrease in membrane resistance. 4. Amiloride elicits a depolarization of the membrane and is accompanied by an increase in membrane resistance. 5. Pre-adapting the tongue to amiloride, which is known as a potent sodium channel blocker, did not alter the responses to sodium-chloride and other taste stimuli.

1. Hedgehog plasma was separated by gel filtration on Sephacryl S-200, the fractions resolved by electrophoresis and the electrophoregrams characterized for trypsin, chymotrypsin and elastase inhibiting activities with both low and high molecular weight substrates. Approximate molecular weights were also determined. 2. At least ten protease inhibitors were characterized in hedgehog plasma including three macroglobulins. 3. The hedgehog protease inhibitors were identified by immunoelectrophoresis. Four protease inhibitors showed homologies with specific human, rat or swine antisera. These were alpha 2-and beta-macroglobulins, alpha 1-protease inhibitor, and alpha 2-antithrombin.

Hedgehog plasma was separated by gel filtration on Sephacryl S-200, the fractions resolved by electrophoresis and the electrophoregrams characterized for trypsin, chymotrypsin and elastase inhibiting activities with both low and high molecular weight substrates. Approximate molecular weights were also determined. At least ten protease inhibitors were characterized in hedgehog plasma including three macroglobulins. The hedgehog protease inhibitors were identified by immunoelectrophoresis. Four protease inhibitors showed homologies with specific human, rat or swine antisera. These were alpha 2- and beta-macroglobulins, alpha 1-protease inhibitor and alpha 2-antithrombin.

The lipid content and composition of marmoset saliva was investigated. Extraction of the dialyzed and lyophilized saliva with chloroform/methanol yielded 15.6 +/- 3.1 mg of lipids/100 ml of saliva. Of the total lipids, 41.7% were represented by neutral lipids, 50.7% by glycolipids and 7.6% by phospholipids. Neutral lipids had a high content of free fatty acids (67.0%), cholesterol and its esters (20.0%) and triglycerides (11.8%). The glycolipid fraction was comprised of simple glycosphingolipids (13.2%), and of neutral and sulfated glyceroglucolipids (86.8%), whereas sphingomyelin, phosphatidylcholine and phosphatidylethanolamine accounted for 63.6% of the total phospholipids. The results indicate that marmoset saliva, in comparison to that of human, contains twice as much of total lipids and exhibits an elevated level of phospholipids, and glycolipids.