Light-Type respirator

In 1942, to meet the need for a lighter respirator more suited to a war of movement, the Light-Type respirator was introduced. This had a canister, filled with activated, impregnated charcoal and a wool-resin mixture, directly attached to the left cheek of the facepiece, and, for the first time, a speech transmitter was incorporated. 

Figure 2. Some typical faceseals (a) single-skin seal, Light Type respirator (b) airbag seal, S6 respirator (c) reflex seal, S10 respirator...

It is obvious that the main physiological function of the A-type ATP-synthase is ATP formation rather than hydrolysis, since it should be responsible for the light- and respiration-dependent ATP supply. As to the ATPase activity, it is strongly suppressed in the membrane-linked enzyme because of the inhibition by bound ADP, a feature resembling the F -ATPase [30,68b]. Nevertheless, at least under certain in vivo conditions, the enzyme can operate as ATPase, for the discharge of A/Ih+ by an uncoupler results in an ATP decrease in cells growing on arginine anaerobically in the dark [30]. 

In rabbits under light amytal anesthesia, chlordan has no direcr effect on the blood pressure, but produces a type of respiration having many characteristics in common with Cheyne-Stokes type. The generalized tremors, opisthotonus, tonic and clonic convulsions, produced by chlordan were decreased or abolished and respiration restored to normal by suitable injections of the sodium salts of amytal, phenobarbital, and pentothal. The LD60 of chlordan, which was about 20 mg. per kg. on intravenous administration to intact rabbits, was increased to about 60 mg. per kg. through the antidotal action of the barbiturates. An unidentified chlorine-containing degradation product with acidic properties was recovered from the urine of rabbits treated with chlordan. Approximately one third of its chlorine content was set free on hydrolysis at 100° C. with sodium hydroxide in either absolute alcohol or in water. 

From the bioenergetic point of view, Halobacterium halobium has been studied much more extensively than other extremely halophilic archaea it is in this species that bacteriorhodopsin was first found. (Later it has also been observed in closely related species H. cutirubrum and H. salinarium [2].) In H. halobium, three types of energy-supplying processes have been identified, namely, (i) respiration, (ii) light-dependent ion pumping and (hi) arginine fermentation (Fig. 1). 

In conclusion we should remark that it is not possible to give a general answer to the question about the inhibition of dark respiration and its different steps in the light.lt depends on the type of plant or on the age of leaf. 

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