Partial starvation, and “in vitro” contractions of rat uterine smooth muscle. Levels of glygogen and trigly-cerides

Abstract

The effects of a restricted-diet (50% of the normal intake during 25 days) on the isometric developed tension (IDT) of uterine horns isolated from diestrous non-cycling rats, were explored. After 60 minutes following isolation and mounting the IDT of controls suspended in glucose containing solution was higher than in preparations from underfed animals but this was no the case in the absence of glucose. Glycogen levels of controls at 60 minutes were smaller in substrate-free than in the presence of glucose whereas no change was detected in horns from restricted-diet rats. Preparations from underfed animals had a significantly augmented basal concentration of triglycerides which diminished at 60 minutes following the removal of glucose from the suspending solution. This effect was abolished by the addition of 3-O-methyl glucose and by blockers of beta-adrenoreceptors such as propranolol or MJ-1999. A similar situation occurs when the animals were injected prior killing with 6-hydroxydopamine.