[Study of the effect of sclareol glycol diterpene on the 3',5'-AMP level]

Sclareol glycol (SG) is a semisynthetic diterpene of the labdanic group. SG is tetranorlabdaniol bivalent alcohol 13, 14, 15, 16-tetranorlabdan-8 alpha, 12-diol, obtained from the plant Salvia sclarea L., grown in Bulgaria. The effects of SG were studied on the level of 3',5'-AMP in:mono-layer tissue cultures of the anterior hypophysis of the rat; in hypophysial and brain tissue during in vitro incubation; in liver microsomes of the rat during in vitro incubation and in liver perfusate of the rat. It was established that SG induced an increase in accumulation of 3,5'-AMP in the tissues from the anterior hypophyses of mature and newborn rats, in the sections of brain cortex and cerebellum of mature rats. Similar changes were found by the diterpene forskolin, studied comparatively. SG induced a reduction of accumulation of 3',5'-AMP in liver microsomes and diminished the release of 3',5'-AMP in a liver perfusate of the rat. The increased accumulation of 3',5'-AMP due to SG could be explained by postreceptor stimulation of the enzyme adenylate cyclase, binding directly to its catalytic subunit. The reduced accumulation of 3',5'-AMP in liver microsomes and its diminished release in liver perfusate could be explained either by activation of the inhibitory adenylate cyclase in hepatocytes or by desensitisation of 3',5'-AMP-generating system.