Insulin levels, humans

This paper summarizes our evidence that the mechanism involves protein stimulation of insulin secretion, followed rapidly by insulin inhibition of renal calcium reabsorption. In humans, urinary calcium was proportional to peak postprandial insulin levels in several experiments, after either protein or sucrose was fed. 

In humans the possibility of mimicking caloric restriction by addition of supplements, fiber, micronutrients, and others that form the group of geronto-ceuticals (i.e., potential antiaging cocktails that may mimic the metabolic or physiological effects of CR) bodes well for the possibility that the extended life and health spans associated with lower body temperature and insulin levels may ultimately be attainable without reduced food consumption or appetite.10... 

Recently, however, an unexpected complication has been associated with the use of human insulin. The transfer of patients from porcine insulin to human insulin has been suggested by some investigators to cause the death of diabetics due to a phenomenon named hypoglycemia unawareness , where there is a loss of sensation in the patient due to a drop in the blood glucose to dangerously low levels. This phenomenon is not associated with porcine insulin, probably due to its better penetration of the blood-brain barrier because of the difference in one amino acid. The experimental evidence is controversial at this time, but will lead to a reevaluation of the safety of human insulin (Wolff, 1992). 

Postprandial glucose-dependent insulinotropic polypeptide (GIP) levels were lowered in a guar-gum-supplemented meal (Morgan et al., 1990) and may contribute to lower insulin levels. Guar delays intestinal calcium absorption in humans (Gulliford et al., 1988b). The decrease in pancreatic amylase release may simply be a result of diminished insular-exocrine axis. 

Insulin by Aerosol. Early studies showed that aerosolized insulin had a bioavailability of 57% after delivery via endotracheal tube into animals, about 10-fold higher than after instillation [125]. Human studies documented average time to peak insulin level at 40 min after aerosol inhalation by human diabetics and normalization of blood glucose [126]. Continuing research focuses on delivery systems [127-129] and particle modification [130,131] to enhance efficacy. Success of these new approaches will depend heavily upon their cost and convenience for patients. At this point, systems seem to depend upon nebulization, a distinct disadvantage for active people. Unless patients quickly recognize aerosolized insulin as distinctly superior to current therapy, e.g., subcutaneous insulin, the method will not gain acceptance. 

The combined effect of (3-CyD with absorption enhancers such as sodium glycocholate or Azone on the nasal absorption of human fibroblast interferon- 3 in powder form in rabbits has been described. HP- 3-CyD was useful as a biocompatible solubilizer for lipophilic absorption enhancers involved in the nasal preparations of peptides.When insuUn was admiifistered nasally to rats, simultaneous use of an oily penetration enhancer, HPE-101, (l-[2-(decylthio)-ethyl]azacyclopentane-2-one) or oleic acid solubilized in HP-(3-CyD showed a marked increase in serum immuno-reactive insulin levels and marked hypoglycemic (Figure 40.11). The potentiation of the enhancing effect of HPE-101 by HP-(3-CyD can be explained by the facilitated transfer of HPE-101 into the nasal mucosa. Studies on the release of membrane proteins and scanifing electron microscopic observations of rat nasal mucosa indicated that the local mucosal damage due to the combination with HP- 3-CyD may not be serious obstacles to their safe use. 

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