Disease relevance of Ranakinin

• Preincubation of adrenal cells with the phospholipase C antagonist U-73122 (1 microM; 18 min) or with pertussis toxin (10 microM; 18 h) totally blocked the ranakinin-induced [Ca2+]i rise [1].

High impact information on Ranakinin

• To elucidate the mechanism of action of ranakinin on the frog adrenal gland, we investigated the effect of ranakinin on cAMP formation and polyphosphoinositide metabolism [2].
• The stimulatory action of ranakinin on inositol phosphate formation and corticosteroid secretion is mediated through activation of a phospholipase C positively coupled to a pertussis toxin-sensitive G protein [2].
• Preincubation of the cells with the calcium channel blockers nifedipine (10 microM) and omega-conotoxin (1 microM) did not alter the response of chromaffin cells to ranakinin [1].
• The effectiveness of the tachykinins tested was: [Pro7] NKB > NKA > ranakinin > [Pro9]SP > SP > kassinin > physalaemin > NKB > [Leu3,Ile7]NKA [3].
• It is concluded that ranakinin is a preferred agonist for the mammalian NK1 tachykinin receptor subtype [4].

Biological context of Ranakinin

• Taken together, these data indicate that in the frog adrenal gland, ranakinin has no effect on the adenylyl cyclase system, but enhances polyphosphoinositide hydrolysis [2].
• The binding site recognised by [125I]BHSP prefers SP and ranakinin [5].

Anatomical context of Ranakinin

• Ranakinin, a naturally occurring tachykinin, stimulates phospholipase C activity in the frog adrenal gland [2].
• Microfluorimetric measurement of cytosolic calcium concentrations ([Ca2+]i) in cultured adrenal cells showed that ranakinin induced a dose-dependent increase in [Ca2+]i in chromaffin cells (ED50 = 2 x 10(-7) M) [6].

Associations of Ranakinin with other chemical compounds

• Taken together, our results show that the frog adrenal gland is innervated by a dense network of peptidergic fibers containing both ranakinin and [Leu3,Ile7]NKA, which, in vitro, stimulates corticosteroid secretion by adrenocortical cells through a prostaglandin-dependent mechanism [3].
• It has recently been shown that the adrenal gland of the frog Rana ridibunda is densely innervated by a network of fibers containing two novel tachykinins, i.e. ranakinin (the counterpart of substance P) and [Leu3, Ile7]neurokinin A [7].
• The selective NK-1 receptor antagonists [D-Pro4, D-Trp7,9]substance P 4-11 and CP-96,345, did not affect the stimulatory action of ranakinin [7].
• In addition, the dual NK-1/NK-2 receptor antagonist FK-224 significantly inhibited the effect of ranakinin on corticosterone (- 80%) and aldosterone secretion (- 95%) [7].

Gene context of Ranakinin

• The effect of ranakinin is mediated through activation of a phospholipase C via a pertussis toxin-sensitive G protein [1].
• Receptor binding profile of neuropeptide gamma and its fragments: comparison with the nonmammalian peptides carassin and ranakinin at three mammalian tachykinin receptors [8].

References