Recent advances in endocrinology / by A.T. Cameron.

  • Alexander Thomas Cameron
Date:
1933
Catalogue details

Licence: In copyright

Credit: Recent advances in endocrinology / by A.T. Cameron. Source: Wellcome Collection.

    172/402 (page 158)
    Oral Administration of Insulin. Since insulin is decom¬ posed by pepsin and trypsin, all efforts to produce a prepara¬ tion which can be used orally must be designed to protect the insulin against this digestive action. I am unaware of any method so far used clinically to which Lawrence’s comment does not apply (102) : “It has been known for years that very large doses of insulin administered by mouth in alcoholic solution or with saponin may occasionally have some slight hypoglycaemic action on the blood sugar of animals and diabetics. But this action is variable and uncertain, and depends on the absorption of some insulin before it is destroyed by the digestive enzymes, a factor over which we have no control.” It has been claimed (123) that blood serum, administered with insulin, confers protection through its “ anti-tryptic activity. It is stated that blood sugar is definitely depressed in rabbits and also in diabetic patients, following oral administration of the precipitate obtained when commercial solutions of insulin are treated with phosphotungstic acid (122). The claim has not been substantiated, and there is obviously potential danger of toxic action on the kidneys from the phosphotungstate (102). The oral use of dry insulin preparations mixed with oily or fatty mixtures, or especially with desoxycholic acid (as “ cholosulin ”) has been advocated and good clinical results claimed (161). The claim is not supported (13). Administration with liver extract is said to favour absorption from the stomach (13). Endonasal application of insulin in the form of a snuff is said to be effective. The blood sugar falls, but no hypo- glycaemia is produced. Carbohydrate tolerance is increased only in some cases (172, 82). Oral Use of Insulin Substitutes. Of various preparations whose use as insulin substitutes has been suggested within the past few years the most promising, and therefore the most disappointing, was synthalin. Watanabe (173) in studies relating to the supposed