Effect of metoclopramide on serum growth hormone levels in cirrhotic men

Growth hormone (GH) secretory response to metoclopramide (MCP) administration was evaluated in 9 male patients with liver cirrhosis and in 6 normal controls. As expected, MCP did not modify serum GH concentrations in normal subjects. In contrast, a striking GH secretory response to MCP was observed in 5 out of 9 cirrhotics. In the other four patients serum GH levels did not show any variation after MCP. The different behavior between cirrhotic “responders” and “non responders” can not be interpreted on the basis of the medical history or the clinical and laboratory data. Three hypothesis are proposed: i) The effect of MCP could be promoted by estrogens and inhibited by androgens. ii) False neurochemical transmitters could affect dopaminergic system of some cirrhotics, allowing or inhibiting the GH response to MCP. iii) MCP could stimulate GH secretion by a serotonergic mechanism. These findings provide further evidence of a modification of the GH secretory pattern in patients with cirrhosis of the liver.