Effect of vasopressin on the expression of genes for key enzymes of hyaluronan turnover in Wistar Albino Glaxo and Brattleboro rat kidneys

Abstract

Hyaluronan (HA), the major glycosaminoglycan of the interstitial matrix, is heterogeneously distributed within the kidney. Using real-time RT-PCR, we tested the assumption that renal HA may be involved in the long-term effect of vasopressin on water reabsorption. The expression of the genes encoding hyaluronan synthase-2 (Has2), hyaluronidase-1 and hyaluronidase-2 (Hyal1 and Hyal2) was studied in the kidneys of Wistar Albino Glaxo (WAG) and homozygous vasopressin-deficient Brattleboro rats treated with the V2 receptor-selective vasopressin analogue dDAVP (100 μg (kg body wt)(-1), i.p., twice a day for 2 days). The Has2 mRNA content was the highest in the kidney papilla of the hydrated WAG and control Brattleboro rats, devoid of vasopressin. In WAG rats, dDAVP induced a considerable decrease in Has2 mRNA content in the papilla, with less pronounced changes in the cortex. The changes elicited by dDAVP in Brattleboro rats tended to be the same as in WAG rats, but weaker. In contrast to Has2, dDAVP treatment caused a significant increase in the Hyal1 and Hyal2 mRNA content in the renal papilla of WAG and Brattleboro rats. In rats of both strains, there was a good fit between Hyal1 and Hyal2 transcriptional levels and changes in hyaluronidase activity in the renal tissue. It is suggested that vasopressin is able to inhibit the synthesis of HA and concomitantly promote its degradation in the interstitium of the renal papilla, thereby facilitating water flow between elements of the renal countercurrent system. The implications for this effect are discussed in the context of the data in the literature.

Urinary hyaluronidase activity is closely related to vasopressinergic system following an oral water load in men: a potential role in blood pressure regulation and early stages of hypertension development

“…As far as we know, this is the first time that such a result has been described. Indeed, the effects of oral water load on hyaluronidase activity have at present been studied essentially in vitro ( 37 – 39 ) or in animal models ( 19 , 23 , 40 , 41 ). In particular, in rats, Stridh et al.…”

“…Their activity is tightly regulated by several factors, including hormones involved in water balance, such as angiotensin II and AVP ( 22 ). Notably, AVP seems to accelerate HA catabolism in renal medullary by increasing both hyaluronidase synthesis and activity ( 23 ).…”

Medical Applications of Hyaluronan

“…Under the action of the ionized exposure on the saturated aqueous solution of N 2 O, practically the only radical particle formed under exposure is the OH radical [46]. Under the action of the ionized exposure on the saturated aqueous solution of N 2 O, practically the only radical particle formed under exposure is the OH radical [46].…”

“…In this regard, the pituitary hormone vasopressin helps water retention in the body by its reabsorption in the renal tubules and thus controls expression of the gene hyaluronan synthase-2 in the kidney [46]. 'Grafting' different bioactive components onto hyaluronan improves the stability of the complex.…”

Effect of NO Synthesis Blockade on the Hydrouretic Function and Extracellular Matrix of the Kidneys in Rats with Different Blood Vasopressin Levels

“…The urine-concentrating process occurs in the inner renal medulla, where the barrier on the way of water passing from the collecting duct (CD) lumen to the bloodstream is presented by not only epithelium, but also the extracellular matrix, with hyaluronan as the main component, separating the elements of the renal countercurrent mechanism [13,14]. Neurohypophyseal hormone vasopressin (VP), one of the main regulators of the renal concentrating function, realizes its antidiuretic effect by increasing the permeability of the principal epithelial cells of CD for water via translocation of aquaporins to the apical membrane [2,5,9,10] and by modulating the expression of genes encoding the key enzymes involved in hyaluronan metabolism and the state of the interstitial matrix [9].…”