Rigor | Smooth Muscle

Studies of rigor mortis recorded in the literature have been made almost exclusively on skeletal muscle, and whatever conclusions there may be regarding its occurrence in smooth muscle seem to have been reached largely by inference from such studies, rather than by actual experimental observations. Wells’ states that all forms of muscle, striped, smooth, and cardiac, undergo rigor mortis, manifested by a shortening and thickening. SaxJ2 investigating the distribution of muscle proteins in bovine uteri, observed no difference between the analyses of tissues fresh and aft,er 24 hours. He did not see a postmortem rigidity of the seuteri. Nasse, according to this investigator, found the intestinal wall firmer several hours after death than immediately post mortem, and concluded that this is a rigor mortis contraction of the intestinal musculature. Hawk,3 referring to Saxl’s study, says there is a difference of opinion regarding the occurrence of true rigor in non-striated (smooth) muscle. Such statements in the literature are sufficiently at variance with the observed contraction