Salt restriction in kidney disease—a missed therapeutic opportunity?

The importance of salt restriction in the treatment of patients with renal disease has remained highly controversial. In the following we marshal the current evidence that salt plays a definite role in the genesis of hypertension and target organ damage, point to practical problems of salt restriction, and report on novel pathomechanisms of how salt affects blood pressure and causes target organ damage

Plant cognition : ability to perceive ‘touch’ and ‘sound’

Plants’ sessile life-style has enabled them to develop enormous sensitivity towards their dynamic, tactile and clamorous surroundings. Consequently, besides a range of different stimuli, plants can even perceive subtle stimuli, like ‘touch’ and unanticipatedly ‘sound’. Importantly, touch sensitivity in plants is not just limited to sensitive plant and carnivorous species, which respond through eye-catchy movements; instead every plant and living plant cell senses and responds to mechanostimulation, whether intrinsic or extrinsic in nature. For instance, plant roots are extremely touch-sensitive, and upon encountering a barrier in soil, they are able to effectively redirect their growth to transcend it. Similarly, tendrils in climbing plants exhibit extreme sensitivity towards touch, which enable them to sense and grab a support in close vicinity. Unlike touch sensitivity, which was recognized long ago by Robert Hooke and Darwin, plants’ sensitivity towards sound has started gaining attention only recently. The past decade has seen major advances in this area of plant biology; many breakthrough discoveries were made that revealed the, otherwise debatable, ecological significance of sound perception in plants’ life. It has come to light that plants not just sense but also distinguish relevant sound among a mixture of irrelevant sound frequencies; plants distinguish buzz produced by a true pollinator among pollen thieves in the sophisticated process of buzz pollination. Similarly, plants distinguish sound typical of a herbivore for elicitation of defence response. Interestingly, plant roots can sense sound of flowing water in order to direct their growth towards the water source. Given the similarity in the physical properties of touch and sound stimuli, many recently discovered signaling events and molecular players in touch and sound perception are noted to be common. However, in view of the contrasting responses tailored according to the stimuli, plants appear to distinguish well among the two in an ecologically meaningful manner

Na⁺/K⁺-pump and neurotransmitter membrane receptors

Na+/K+-pump is an electrogenic transmembrane ATPase located in the outer plasma membrane of cells. The Na+/K+-ATPase pumps 3 sodium ions out of cells while pumping 2 potassium ions into cells. Both cations move against their concentration gradients. This enzyme’s electrogenic nature means that it has a chronic role in stabilizing the resting membrane potential of the cell, in regulating the cell volume and in the signal transduction of the cell. This review will mainly consider the role of the Na+/K+-pump in neurons, with an emphasis on its role in modulating neurotransmitter receptor. Most of the literature on the modulation of neurotransmitter receptors refers to the situation in the mammalian nervous system, but the position is likely to be similar in most, if not all, invertebrate nervous systems.</p