Involvement of endothelins in deoxycorticosterone acetate-salt hypertension through the modulation of noradrenergic transmission in the rat posterior hypothalamus.

What is the central question of this study? Does ex vivo administration of endothelin-1 and endothelin-3 regulate noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate-salt hypertensive rats compared with normotensive rats? What is the main finding and its importance? Endothelin-1 and endothelin-3 enhanced diverse mechanisms leading to increased noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate-salt hypertensive rats. Unveiling the role of brain endothelins in hypertension would probably favour the development of new therapeutic targets for the treatment of essential hypertension, which still represents a challenging disease with high mortality. Brain catecholamines participate in diverse biological functions regulated by the hypothalamus.

Enhanced assymetrical noradrenergic transmission in the olfactory bulb of deoxycorticosterone acetate-salt hypertensive rats.

The ablation of olfactory bulb induces critical changes in dopamine, and monoamine oxidase activity in the brain stem. Growing evidence supports the participation of this telencephalic region in the regulation blood pressure and cardiovascular activity but little is known about its contribution to hypertension. We have previously reported that in the olfactory bulb of normotensive rats endothelins enhance noradrenergic activity by increasing tyrosine hydroxylase activity and norepinephrine release.

Calcium-dependent mechanisms involved in the modulation of tyrosine hydroxylase by endothelins in the olfactory bulb of normotensive rats.

Endothelins (ETs) are widely expressed in the olfactory bulb (OB) and other brain areas where they function as neuropeptides. In a previous study we reported that in the OB ET-1 and ET-3 participate in the long-term regulation of tyrosine hydroxylase (TH), the key enzyme in catecholamine biosynthesis. ETs stimulate TH activity by increasing total and phosphorylated enzyme levels as well as its mRNA.

Atrial natriuretic factor stimulates efflux of cAMP in rat exocrine pancreas via multidrug resistance-associated proteins.

Background & Aims: Atrial natriuretic factor (ANF) prevents increases in intracellular levels of cAMP that are induced by secretin in the exocrine pancreas. We investigated the contribution of cyclic adenosine monophosphate (cAMP) efflux to ANF inhibition of secretin signaling.

Methods: Intracellular and extracellular cAMP were measured by radio-binding assays in isolated pancreatic acini exposed to secretin and other secretagogues, alone or with ANF.

Mechanisms involved in the long-term modulation of tyrosine hydroxylase by endothelins in the olfactory bulb of normotensive rats.

The olfactory bulbs play a relevant role in the interaction between the animal and its environment. The existence of endothelin-1 and -3 in the rat olfactory bulbs suggests their role in the control of diverse functions regulated at this level. Tyrosine hydroxylase, a crucial enzyme in catecholamine biosynthesis, is tightly regulated by short- and long-term mechanisms.

Endothelins participate in the central and peripheral regulation of submandibular gland secretion in the rat.

We previously reported that endothelins (ETs) are involved in the rat central and peripheral regulation of bile secretion. In this study we sought to establish whether ET-1 and ET-3 modulated submandibular gland secretion when locally or centrally applied. Animals were prepared with gland duct cannulation to collect saliva samples and jugular cannulation to administer sialogogues.

Culture and characterization of human hepatocytes obtained after graft reduction for liver transplantation: a reliable source of cells for a bioartificial liver.

This article describes results obtained when human liver cells obtained from reduced grafts are cultured in a chemically defined medium. Remnants of livers after reduction for pediatric transplantation were processed by a multiple cannulation system through the existing vasculature, which allowed the homogeneous perfusion of collagenase. The graft weight ranged between 55 and 1000 g (median value: 145.