The role of ranitidine infusion on glucose, insulin and C-peptide serum levels induced by oral glucose tolerance test in healthy subjects.

In 9 healthy subjects we evaluated the effect of a constant ranitidine infusion (100 mg) on glucose (mg/dl), insulin (microU/ml) and C-peptide (ng/ml) serum levels promoted by oral glucose tolerance test (75 g). Ranitidine significantly increased the area under concentration/time curves for glucose and insulin but not that of C-peptide. Our data indicate that ranitidine does not affect pancreatic insulin release nor peripheral glucose utilization and are consistent with the hypothesis that ranitidine influences the hepatic clearance of glucose and insulin both of which undergo high first-pass liver extraction.

[Diabetic neuropathy. III: Autonomic neuropathy. Genito-urinary system]. / La neuropatia diabetica. III: Neuropatia autonoma. Apparato genito-urinario.

When considering urogenital complaints occurring during diabetic autonomous neurotherapy , three clinical situations are important due to their frequency and the clinical situation, the considerable effect they have on quality of life. In addition they may also be responsible for severe complications as in the case of diabetic cystopathy . This syndrome is the cause of considerable subjective disturbances even though it may be diagnosed instrumentally in its early, completely asymptomatic stage. The complaint evolves inevitably towards bladder denervation, chronic urinary retention and more or less severe septic complications. Retrograde ejaculation may lead to the loss of procreative ability as in the case of neurogenic impotence in diabetics. These three autonomous neuropathic situations occur quite frequently, especially in older subjects who have suffered from diabetes for more than ten years. Often the three syndromes are interconnected or linked to autonomous or peripheric neuropathic complaints affecting other areas. The few therapeutic measures practised have not proved very conclusive. Only a diligent examination of signs and symptoms with the aim of early diagnosis and the maintenance of good glycometabolic balance are considered to be at all effective as preventive measures.

[Diabetic neuropathies. IV. Autonomous neuropathy. Peripheral sympathetic innervation and the cardiovascular system]. / La neuropatia diabetica. IV. Neuropatia autonoma. Innervazione simpatica periferica e apparato cardiovascolare.

The clinical conditions due to damage to the peripheral sympathetic nervous system during diabetic neuropathy mainly involve alterations to subcutaneous vasomotility , temperature body regulation and exudation, which may take form of hyper or hypoactivity. Gustatory exudation and local anhydrosis are described in detail as well as the connection with aggravating factors like long duration, poor balance and early onset of diabetes mellitus . Change in the relevant cardiovascular reflexes, commonly used in diagnosing diabetic neuropathy, are also analysed with a discussion of their physiopathological background and clinical significance. Finally the painless infarct, sudden death and abnormal response to hypoglycaemia, that are the common features of diabetic neuropathy, are also described.