Evidence that catecholamines stimulate renal gluconeogenesis through an α1-type of adrenoceptor

Abstract

1. Noradrenaline stimulates gluconeogenesis through an alpha-adrenoceptor in renal cortical tubule fragments from fed rats incubated with 5 mM-lactate. 2. The selective alpha 1-adrenoreceptor agonist methoxamine stimulated gluconeogenesis, but the selective alpha 2-adrenoceptor agonist clonidine was ineffective. 3. The selective alpha 1-adrenoceptor antagonist thymoxamine blocked the stimulatory effects on gluconeogenesis of noradrenaline and of oxymetazoline (a synthetic alpha-agonist). The selective alpha 2-adrenoceptor antagonist yohimbine was ineffective in this respect. 4. It is concluded that noradrenaline and oxymetazoline stimulate gluconeogenesis in rat kidney via an alpha 1-rather than an alpha 2-type of adrenoceptor.

α1b‐Adrenoceptors mediate renal tubular sodium and water reabsorption in the rat

“…(Elhawary et al, 1992). Furthermore, SZL-49 (Elhawary et al, 1992) and the Ca2l entry blocker, nifedipine (Han et al, 1990) (Osborn & Harland, 1988), stimulation of gluconeogenesis (Kessar & Saggerson, 1980) and, increased renovascular resistance (Cooper & Malik, 1985;Wolff et al, 1987;DiBona & Sawin, 1987;Jeffries et al, u) 1987). Intrarenal arterial infusion of PE in anaesethetized rabbits, at a dose which did not alter renal haemodynamics, significantly reduced urine flow and absolute and fractional * Nat excretion by about 15, 23, and 23% respectively (Hesse & Johns, 1985).…”

Stimulation of α1‐adrenoceptors in rat kidney mediates increased inositol phospholipid hydrolysis

“…Evidence tion of these responses is seen in kidney, where activation of a,-ondary effects adrenoceptors leads to increased sodium reabsorption for multiple (Osborn et al, 1983;Hesse & Johns, 1984), prostanoid production (Cooper & Malik, 1985), gluconeogenesis (Kessar & Saggerson, 1980;McPherson & Summers, 1982), renal vasoconstriction (Schmitz et al, 1981;Smyth et al, 1984;Cooper & Malik, 1985) and inhibition of renin release (Matsumura et al, 1985). In the light of the large quantity of physiological data, it is of great interest that the present study demonstrated that renal a,-adrenoceptors are linked to PI metabolism and that the products of the PI cycle can now be investigated as possible mediators of the diverse array of physiological processes occurring in response to a,-adrenoceptor activation in the kidney.…”

“…Alternatively, arachidonic acid may be generated from other membrane phospholipids by Ca2+ stimulation of phospholipase A2 (Billah et al, 1980). Another response, gluconeogenesis, is stimulated by activation ofa,-adrenoceptors in rat kidney and is partially Ca2+-dependent (Kessar & Saggerson, 1980;McPherson & Summers, 1982). Hormonal regulation of gluconeogenesis is thought to occur at specific points (KrausFriedmann, 1984).…”

“…The indomethacin-sensitive component of the PI response may be only one component of the Ca2"-stimulated increased control levels of [3HJ-IP's. Gluconeogenesis is a calcium-dependent process stimulated by activation of a,-adrenoceptors in rat kidney (Kessar & Saggerson, 1980;McPherson & Summers, 1982). Glucose is able to cause a PI effect in liver (Fex & Lernmark, 1972) and so may also warrant consideration as a candidate for the role of an endogenous stimulant of PI turnover.…”

“…shown to be functionally relevant in that they are coupled to adenylate cyclase (Woodcock & Johnston, 1982;Chabardes et al, 1984) while stimulation of a,-adrenoceptors mediates enhanced prostanoid release (Cooper & Malik, 1985), gluconeogenesis (Kessar & Saggerson, 1980;McPherson & Summers, 1982), renal vasoconstriction (Schmitz et al, 1981;Smyth et al, 1984;Cooper & Malik, 1985) and inhibition of the release of renin (Matsumura et al, 1985). Sodium reabsorption is stimulated following administration of z,-adrenoceptor agonists in rabbit (Hesse & Johns, 1984) and dog (Osborn et al, 1983) kidney and is known to compete with gluconeogenesis for available oxidative energy in kidneys of steroid-treated rats (Silva et al, 1980).…”