Effect of pectic substances on prolactin and growth hormone secretion in the ewe and on the induction of casein synthesis in the rat.

Pectins from apple, citrus and sugar beet injected intravenously to ewes markedly stimulated blood prolactin, growth hormone (GH) and cortisol. Pectic acid and polygalacturonic acid exhibited the same property. A preparation of oligogalacturonic acid with a polymerisation degree of 12 to 13 was also active, whereas oligomers with a smaller degree of polymerisation (congruent to 10) were devoid of activity. Pectic acid administered orally to mature virgin rats induced the accumulation of beta-casein in mammary gland. Pectins and some of their derivatives therefore had a lactogenic property and their effect probably resulted from a capacity to trigger lactogenic hormone secretion.