Cardiovascular effects of insulin.

Abstract

The reduction was small but could not be explained in terms of seasonal variation in folate intake and it suggests that smallbowel absorption may be affected by the fibre content of the diet. The mechanism might be similar to that of cholestyramine ' in lowering serum folate levels.The colonic flora may be changed by additional fibre. The urinary indican test is a crude indicator of gastrointestinal bacterial activity, but we found no consistent pattern of change.In the past dietary fibre has been considered physiologically inert. Interest in its metabolic role is now increasing, but research is still at an early stage. We hope that our findings will indicate some further lines of inquiry. In the meantime we conclude that we have not detected any metabolic effect that would contraindicate the use of bran in diverticular disease.We thank Miss P Hewitt, Mrs 0 Patrick, and Miss S Smith of the dietetic department, the nurses of Loddon ward, and the staff of the biochemistry department, Royal Berkshire Hospital, for their help; Dr E V Cox and the general surgeons for their co-operation and encouragement; Mr C Latto and Dr J I Mann for their advice; and Dr P H Coldwell for his radiological help. We are also grateful to the staff of the department of medical illustration, Radcliffe Infirmary, Oxford, for the illustrations and Mrs M Thorogood for the statistical analyses.All three studies form part of the work for an MS thesis (AJMB Medical3Journal, 1976, 1, 430-432 Summary Insulin increased the heart rates of seven diabetics with normal cardiovascular reflexes. This effect, which was not due to hypoglycaemia, was greater in the upright than in the supine position and was produced by as little as one unit given intravenously. This increase in heart rate may be a compensatory response to maintain cardiac output. IntroductionRecent observations have shown that insulin has an effect on the cardiovascular system that is independent of hypoglycaemia12; it provokes postural hypotension in diabetics with autonomic neuropathy' 2 and in patients who have had a sympathectomy.3 We aimed to determine whether a cardiovascular effect of insulin occurs in all diabetics or in only those with neuropathy.

The effect of intravenous insulin infusion on kidney function in insulin-dependent diabetes mellitus

“…The suggestion of increased sympathetic nervous activity as the dominant mechanism involved was based upon prior reports of enhanced heart rate and increased plasma noradrenalin concentration in IDD patients after an intravenous bolus injection of 6 to 20 U of insulin [9,10,11]. Heart rate did not however increase in our study (A) with plasma insulin levels within the physiological range.…”

Identification and characterization of a gene regulating enzymatic glycosylation which is induced by diabetes and hyperglycemia specifically in rat cardiac tissue.

“…It is not surprising that insulin was shown to affect gene expression in the heart since multiple studies have documented that myocardium is responsive to insulin at biochemical and physiological levels (34, 48). Clinically, insulin treatment has been reported to improve cardiac function in diabetic patients (49). At the molecular level, a great deal of information is available on insulin's action on gene regulation, not specifically on cardiomyocytes (50).…”

Catecholamines and diabetes mellitus

“…Intravenous injection of insulin increases plasma NA [32,35,70] and heart rate [70,114] and decreases peripheral blood flow [70]. However, despite the increase in plasma NA and heart rate after IV insulin, arterial blood pressure remains unchanged in subjects with an intact autonomic nervous system and may even decrease in patients with autonomic neuropathy [61, 102, 103 115].…”