Histological Study of Effects of Relaxin on the Bovine Cervix

Abstract

Cattle were treated with relaxin following sensitization with progesterone, diethylstilbestrol, or both, and a histological study of cervical biopsies undertaken to determine the cellular changes produced by relaxin. Results were then compared with cervical changes which occur during natural parturition. Cervical tissue from cattle injected with relaxin following sensitization with progesterone showed muscle fiber elongation and a small amount of fluid infiltration; those with relaxin following injections of diethylstilbestrol showed more pronounced infiltration ; and cattle which received relaxin after being primed with both progesterone and diethylstilbestrol showed muscle fiber elongation and a large amount of fluid uptake, with consequent relaxation and dilatation of the cervical passage. Cattle which received only relaxin showed muscle fiber elongation but no fluid increase. Cervical tissue from an animal following normal parturition yielded results comparable to cervical tissues treated with relaxin following sensitization with progesterone and diethylstilbestrol. © 1966, American Dairy Science Association. All rights reserved.