Contact chemoreceptors on the mouthparts and legs of the blowfly Phormia regina that normally respond to aqueous solutions of sapid substances also respond to compounds in the gaseous state. Effective vapors include organic and inorganic acids and various unrelated nonpolar compounds. In general, the acids stimulate the salt receptor. Some nonpolar compounds stimulate the salt receptor while ot...

• In the vagotomized dog with deafferented peripheral chemoreceptors, hypoxia, hypercapnia, or ischemia of the central nervous system provokes reflex, positive chronotropic and inotropic effects upon the normally oxygenated heart. Bradycardia and depression of myocardial contractility are considered to be the primary reflex effects upon the canine heart elicited by stimulation of the chemorecep...

IT IS AXIOMATIC that the respiratory chemoreceptors sense and respond to changes in the composition of their immediate microenvironment.78 In humans, the ventilatory response to a step change in end-tidal CO2 yields a fast (τ ∼10 s) and a slow component τ ∼120 s).12,40 Two sets of chemoreceptors are thought to elicit these two components: the peripheral chemoreceptors, causing the fast componen...

There are afferent nerve fibers responsive to alterations of the kidney's chemical environment in the renal nerves of the rat. In anesthetized, artificially ventilated, male Sprague-Dawley rats, single unit recordings were prepared by dissection of the centrally cut nerves of the right kidney. The stimuli used included occlusion of the renal artery, systemic asphyxia, changes in renal arterial ...

Anatomical and electrophysiological techniques were employed to investigate the aortic bodies in anesthetized puppies and dogs. The microscopic appearance, location, innervation, and vasculature of the aortic bodies were investigated by microdissection and histological examination of gelatineinjected preparations. Thoracic chemoreceptor impulses were recorded from the cervical vagus nerves, the...

The peptidergic innervation of arterial chemoreceptor organs (the rat carotid body and vagal paraganglia; guinea pig carotid body) was studied immunohistochemically. Five different populations of nerve fibres in the guinea pig carotid body could be discriminated according to their origin and their chemical coding. The innervation pattern of the rat carotid body differed in some aspects. Compari...

Four chemoreceptors in Escherichia coli mediate responses to chemicals in the environment. The receptors self-associate and localize to the cell poles. This aggregation implies that interactions among receptors are important parameters of signal processing during chemotaxis. We examined this phenomenon using a receptor-coupled in vitro assay of CheA kinase activity. The ability of homogeneous p...

B acterial and archaeal microbes possess a wide array of surfacedeployed receptors for monitoring their chemical and physical surroundings. Particularly prominent among microbial chemoreceptors are the so-called methyl-accepting chemotaxis proteins (MCPs), which sense changes in the cell’s chemical environment and generate intracellular signals that control the organism’s pattern of locomotion ...