[Heptaminol chlorhydrate: new data].

Heptaminol hydrochloride is widely used for the treatment for orthostatic hypotension. It continues to elicit controversy as to its mode of action since Loubatières (1951) described its powerful inotropic action on an ischaemic preparation. Twenty five years later it has been suggested that this drug exerts its action by interfering with the release and uptake of catecholamines (Grobecker and Grobecker, 1976). The aim of this review was to report new experimental approaches and new data relative to the mode of action of heptaminol hydrochloride. In the rat, heptaminol hydrochloride prevented orthostatic hypotension, and increased the noradrenaline plasma concentration. In bovine chromaffin cells maintained in primary cultures, it was found to be a competitive inhibitor of noradrenaline uptake. This inhibition may partially account for its antihypotensive effect. The cardiotonic effect was studied using 31 P nuclear magnetic resonance spectroscopy and left ventricular pressure measurement in rat isolated hearts. The results suggest that the inotropic effect during moderate ischemia could be related to a restoration of internal pH possibly mediated by a stimulation of the Na+/H+ exchange. The satellite cells of adult skeletal muscles are myogenic cells involved in muscle regeneration. In culture, they differentiate into myotubes and thus mimic some aspects of the in vivo myogenic process. Heptaminol hydrochloride, which did not significantly alter the cloning efficiency or proliferation, increased the capacity of satellite cells to differentiate into myotubes.