[Secretion of gastric acid, gastrin and cyclic nucleotides in relation to the action of the vagus nerve].

Changes on levels gastric acidity, on serum gastrin, cAMP and cGMP levels were studied in 18 healthy volunteers after either stimulation (injection of 0.2 IU of soluble insulin/kg body weight to a group of 9 subjects) or stimulation and inhibition (injection of insulin plus atropine per os to the other group of 9 subjects) of the vagus nerve. After vagus nerve stimulation, gastric acid levels, serum gastrin and cGMP were raised and cAMP reduced.

[Cyclic GMP in the eye and its correlation with externally administered insulin].

Experiments carried on Albino rabbits for detecting cyclic GMP in the eye tissues and to observe whether cGMP is influenced through local administration of insulin to the eye, externally. Whereas, for instance, intraveinous administration of insulin does not influence, in any way, concentration of cGMP -- after 3' to 10' -- in the humour aqueous, the lens, the vitreous body and the blood serum, following administration of insulin by means of retrobulbar injection, for the same time and on the same tissues, the values of cGMP appear increased. On the other hand, results yielded by our experiments allow us to estimate that environment preparing cGMP in the eye is the retina and the choroid.