Thyroxine-evoked decrease of jejunal lactase activity in adult rats.

  title={Thyroxine-evoked decrease of jejunal lactase activity in adult rats.},
  author={Paul Celano and Jocelyn Jumawan and Otakar Koldovsk{\'y}},
  volume={73 2},

Lactase activity is under hormonal control in the intestine of adult rat.

Thyroxine injection during the three days before death inhibited the stimulation of lactase activity induced by starvation without modifying sucrase activity whereas hydrocortisone injections or thyroidectomy did not modify the stimulatory effect of starvation on lact enzyme activity.

Decrease of lactase activity in the small intestine of jejunum-bypassed rats.

Lactase activity in residual ileum is not only unable to compensate for the loss of digestive-absorptive surface of jejunum, but lactase activity even decreases followingJejunum-bypass operation, suggesting that some hormonal factor(s) might be involved in the decrease of lactases activity in jejunal bypassed animals.

Early changes in brush border disaccharidase kinetics in rat jejunum following subcutaneous administration of tetraiodothyronine

The results indicate a direct effect of tetraiodothyronine on jejunal brush border disaccharidases of the rat, and an effect mediated by an altered enterocyte turnover is unlikely to occur.

Dietary induced increase of lactase activity in adult rats is independent of adrenals

Adult rats fed 10 days a low starch-high fat diet were either adrenalectomized or sham-operated and force-fed the same diet another 5 days; 14 h before sacrifice, some animals were force-fed a

Dietary sucrose enhances intestinal lactase gene expression in euthyroid rats.

Dietary sucrose is capable of enhancing lactase gene expression in starved rats when they have a sustainable thyroid hormone level, and up-regulated the LPH gene expression and lactase activity by force-feeding a sucrose diet.

Dependency of lactose absorption on lactase activity in starved rats.

It is shown that the increase of intestinal lactase activity induced by starvation of adult rats correlates with in vitro increased lactose absorption.

Adaptation of intestinal hydrolases to starvation in rats: effect of thyroid function

The results indicate that intestinal hydrolases respond non-coordinately to long-term food deprivation and suggest that the drop in plasma thyroid hormones during fasting allows a better maintenance of protein content and of hydrolase activities in the brush border membranes of the small intestine.

Thyroid hormone effects on lactase expression by rat enterocytes.

The results are discussed in relation to what is already known concerning the ability of thyroid hormones to affect intestinal development and the future need to study the physiological effects of T3 at the cellular level in the intestine.

Effects of starvation and refeeding on jejunal disaccharidase activity

In the rat, starvation lowers jejunal sucrase activity and increases or has no effect upon jejunal lactase activity. The mechanism by which starvation influences these intrinsic microvillus proteins



Thyroxine-Evoked Precocious Decrease of Acid Hydrolases in the Ileum of Suckling Rats 1

Thyroxine treatment caused a precocious decrease of acid-β-galacto-sidase, β-glucuronidase and N-acetyl-β -glucosaminidase in the ileum of the small intestine and evoked also a precocity increase of jejunal sucrase and maltase activities.

Intestinal Lactase Activity in the Suckling Rat: Influence of Hypophysectomy and Thyroidectomy

  • K. YehFlorence Moog
  • Biology, Medicine
  • 1974
The thyroid gland appears to play a previously unsuspected role in intestinal maturation, which is high in the infant rat intestine but falls to a low level by the end of the third week.

Effect of cortisone on the developmental pattern of the neutral and the acid beta-galactosidase of the small intestine of the rat.

Acid beta-galactosidase activity is decreased after cortisone treatment in 8-, 12-, 16- and 18-day-old rats, with sensitivity to cortis one increasing with the approach of weaning, and neutral beta-Galactoside activity is increased in the ileum of 8-and 12-day old rats, but only in the jejunum of 7-and-12- day old rats.

Effect of thyroidectomy on the activity of alpha-glucosidases and acid hydrolases in the small intestine of rats during weaning.

Thyroidectomy performed simultaneously with adrenalectomy on 14-day-old rats caused a further substantial delay in the maturation of the enzyme profile of the small intestine, indicating that the thyroid is involved in regulation of the hydrolases studied.

Cell migration and cortisone induction of sucrase activity in jejunum and ileum.

It was found that the sensitivity of the small intestine producing system to cortisone stimulation increased during the suckling period and this increase was due to at least three factors: increase of activity in newly differentiating cells, increased percentage of villus cells with sucrase activity and continued production or activation of suCrase activity as the cells migrate along the villi.


Feeding a lactose diet to infant rats from day 14 postnatally in the presence of the mother rat slows down the decrease in beta-galactosidase activity and this is not found with a diet containing glucose and galactose instead of lactose.


Intestinal mucosal hyperplasia following induced hyperthyroidism in the rat

The administration of thyroid hormone to the rat resulted in hypertrophy of the small intestine that involved the intestinal mucosa to a greater degree than the muscular layer, and was most marked in the jejunum.