Physiologic effects of administration of interleukin 1β in cows

Summary The immunomodulating polypeptide interleukin 1β (il-1β) has been shown to be homologous to osteoclast-activating factor and is capable of stimulating increased osteoclastic bone resorption. This effect prompted an investigation into the potential use of il-1β for prevention of parturient paresis, a disease of dairy cows characterized by hypocalcemia and poor osteoclastic resorption of bone. Six nonpregnant cows were treated with a high dosage of il-1β (166 ng/kg of body weight) every 8 hours for 4 days. The il-1β treatment significantly (P < 0.05) increased urinary hydroxyproline excretion, an index of osteoclast activity, indicating that bone calcium resorption might be stimulated by il-1β treatment of cows. However, il-1β treatment also caused transient fever, inappetence, increased pulse and respiratory rate, and diuresis. The acute, but transient, effect of il-1β treatment was to cause a decrease in plasma calcium and phosphorus concentrations. The pleiotropic effects of il-1β administration negated the positive effects on osteoclastic bone resorption, and indicates that this cytokine may be of minimal benefit for prevention of parturient paresis.